biological management

8/9/2019 Biological Management

1/27

Biological Control of Weeds on the PrairiesUpdated: March 2004IntroductionThere are some very tough weeds on the prairies. They compete with valuable crop and forage plants and threatenmany native plant species.Many of these weeds have been very expensive and difficult if not impossible to control with more traditionalmethods. !n some instances the chemicals used for control are non"selective compounds which will also damagenon"target plants and may leach out of sandy or gravelly soils or compounds that give top growth control only. !naddition because of leaching chemicals cannot be used on weeds that grow close to bodies of water.Many problem weeds are abundant in rangeland and along riverban#s and gullies so the use of non"chemical controlmethods such as mowing or cultivation can be limited by the topography and si$e of these areas. These difficultieshave prompted scientists to investigate a third alternative: the biological control of weeds.

What is biological control?%iological control covers two #ey concepts: the deliberate use of a weed&s 'natural enemies' to suppress itspopulation and the use of these live organisms to maintain this lower population density. ( weed&s natural enemiesmay be arthropods )insects mites and their relatives* bacteria or fungi. These 'control agents' feed upon or causedisease in the weed thereby limiting its growth reproduction and spread.There are two distinct primary approaches to weed biocontrol: classical and inundative.+lassical )inoculative* biocontrol involves the release of a relatively small number of control agents. These agentsfeed on the weed reproduce and gradually suppress the weed as their population grows. ,or this approach

arthropods are generally used as control agents.!nundative biocontrol. !n this type of biological control large -uantities of a control agent generally a pathogen )abacteria or fungus that causes disease in a weed* are applied to weeds in much the same manner as a chemicalherbicide would be.

How are biological control agents identified and introduced?tep /: !dentifying target weeds To be considered a good candidate for biological control a weed should be:

/. non"native

2. present in numbers and densities greater than in its native range and numerous enough to causeenvironmental or economic damage. The weed should also be

. present over a broad geographic rangehave few or no redeeming or beneficial -ualities

4. have taxonomic characteristics sufficiently distinct from those of economically important and native plantspecies

1. for classical biocontrol the weed should occur in relatively undisturbed areas to allow for the establishmentof biological control agents. +ultivation mowing and other disturbances can have a destructive effect on manyarthropod biocontrol agents. !nundative biocontrol agents such as bacteria and fungi are less sensitive tothese types of disturbances so may be used in cropland.

tep 2: !dentifying control agents and assessing level of speciali$ation cientists observe weeds in their areas oforigin )(sia and urope in the case of many weeds in +anada* and collect the insects and other organisms attac#ing

the plants and affecting their survival. Most of the pathogens being examined as biocontrol agents are native to 3orth(merica.These organisms are subected to a multi"level screening process to assess their host range and their effect on theweed. These screening efforts do two things: they ensure the safety of any valuable crop forage or native plantspecies that the agents may encounter when released and they assess the efficacy of the agent.

(ssessing the host range )how specific the potential biocontrol agent is to a particular plant* is probably the mostimportant step in this process. 5ver very long periods some plants and herbivores have evolved to form very closeassociations. 6lants have developed a number of defenses such as toxic chemicals that plant"eating organisms)herbivores* must overcome. ome herbivores have evolved the ability to bypass only certain host plantTMs defensessuch that they cannot feed or develop on anything else.


2/27

To find out how speciali$ed a particular agent is scientists collect and expose them to a wide assortment of plants.These plants include crop and forage species as well as species native to the intended release area especially if thespecies are close relatives of the weed. creening potential biological control agents ensures that only those with avery narrow host range )i.e. those that represent no threat to crop forage or native species* are released.tep : +ontrolled release (ll biological control agents must be approved under the 6lant 6rotection (ct and arereviewed by an advisory panel of (griculture and (gri",ood +anada before they can be released. ,ollowing federalapproval the agents are released on their target weeds at selected experimental sites which are closely monitored.

7ata from these sites help to assess both the agentsTM

potential for survival under field conditions in western +anadaand their potential to cause damage to the target weed.tep 4: ,ull release and identifying optimal release sites !f the agents survive our harsh climate and damage orsuppress the weeds in the controlled tests they can be released on other weed infestations.The agents are released on as many varied sites as agent numbers time and resources will permit. 3ote thatinstructions for the proper method and timing of agent releases should be followed closely and these instructions willvary with the species of agent. The agents are then carefully monitored. 8elease on a large variety of sites allowsscientists to find the habitats best suited to each species.Many types of biological control agents spend at least part of their lives underground and can be very sensitive to thesoil types and conditions present in the various areas. ,or example the blac# dot leafy spurge beetle (phthonanigriscutis spends its entire larval stage underground feeding on leafy spurge roots. !nformation gathered from anumber of release sites indicates that these beetles prefer dry sandy soils and will not do nearly as well in soils withhigher moisture levels.tep 1: Monitoring release sites )classical* 8elease sites should be monitored periodically to assess the si$e of thebiological control agent population and the effect of the agent on the weed. ( sweep net is particularly useful for

sampling insect biological control agents that feed on the foliage of the weed. ),igure /*.

,igure /. ( sweep net helps in monitoring.

Monitoring release sites is very important to determine if agents have established on a site. ome insect biocontrol

agents may need two to five years before their populations increase to a sufficient si$e to have a visible impact onweed numbers.9hen the classical control agent is establishing on a weed infestation and increasing its numbers the site should notbe mowed or disturbed. erbicide may be used along the boundaries of the weed infestation to help contain the weedwhile the biological agent is increasing in population and spread.tep ;: 8edistribution )classical* !f a biological control agent is released on a site with favourable conditions itspopulation can grow -uic#ly.

( large number of insects can suppress the weed in this area and may allow for the establishment of an 'insectary'.This is an area where the insect population has grown to the point where the insects can be collected in very largenumbers. !nsects collected from these sites can be distributed to other weed"infested areas. 5nce established theinsects can suppress the weeds in these areas as well. (n important point to remember is that it can ta#e yearsbefore a biocontrol agent.s population reaches this si$e. The agents should not be collected for redistribution beforethis time.

,igure 2. 8elative weed and biological control agent population si$e


3/27

tep there is little danger of damage to non"target plantspecies. %iological control agents are also very effective in inaccessible areas.

(nother attractive feature of biological control is its negligible environmental impact. This weed control method doesnot bring any of the problems associated with herbicide residues contaminated groundwater and weed resistance toherbicides.!ndividual applications of classical biological control are also potentially much less expensive over time. ( smallnumber of biocontrol agents can once established grow to very high densities and provide continuous control of aweed over a large area.9hen the cost of development is considered classical biocontrol is generally less expensive than chemical control.+lassical biological control does have its limitations however. !t lac#s the immediacy of chemical control. 6opulationsre-uire time to become established so signs of weed suppression are rarely evident in the first year. creening wor#)determining the selectivity and effectiveness of a biocontrol agent* is also very time consuming and is subect tolimited funding.

A prairie success story

,igure . ?eafy spurge biocontrol )dmonton*

erbivorous insects have shown the greatest potential as classical biological control agents and most of the wor# on

the biological control of weeds on the prairies involves their use ),igure *.valuating the effectiveness of these insects to control some of the worst weeds on the prairies is the focus of muchresearch by (lberta (griculture ,ood and 8ural 7evelopment as#atchewan (griculture and ,ood Manitoba

(griculture the (lberta 8esearch +ouncil and (griculture and (gri",ood +anada in cooperation with agencies fromaround the world.The most successful insect to be used in the prairies is the black dot spurge beetle)Aphthona nigriscutis*. 8eleaseof these insects on leafy spurge has resulted in a @@ per cent reduction in spurge stand density in one area and acorresponding 0"fold increase in grass biomass after four years.

,igure 4. ?eafy spurge has become a serious problem

eafy !purge)Euphorbia esula* is a deep"rooted noxious perennial weed that was accidentally introduced to 3orth(merica in the early /A00&s ),igure 4*. The plants grow to a height of / metre have long thin dar# green leaves andcan be identified from a distance by their distinctive yellow"green flowers. ince its introduction it has spread tobecome a very serious problem on rangeland pasture and grassland throughout the southern prairies and is


4/27

gradually wor#ing its way north. year. ach adult female is capable of producing about /10 offspring in a growingseason. This control agent does best in dry sandy soils ),igure ;*.?eafy spurge is very competitive and easily out"competes many forage and native plant species. The uice of theplant is a white mil#y latex that may cause mouth and throat blistering in cattle and contact dermatitis in people.!ngestion of large amounts of leafy spurge has been suspected of causing death in cattle.+attle avoid spurge"infested areas greatly reducing the livestoc# carrying capacity of infested range and pastureland.?eafy spurge has proven to be very difficult and expensive to control with herbicides and virtually impossible to

control with cultural techni-ues.

,igure 1. %lac# dot spurge beetle

5riginating in urope the blac# dot spurge beetle )Aphthona nigriscutis* measures 2 to mm in length. (dult beetlesfeed on the foliage of the weed and larvae feed on the roots ),igure 1*.

,igure ;. Bood blac# dot spurge beetle release site

The larvae cause most of the damage to the plant both directly through their root and root hair feeding andsecondarily by creating feeding wounds that provide an entry for various disease"causing organisms. The blac#"dotspurge beetle produces one generation per year. ach adult female is capable of producing about /10 offspring in agrowing season. This control agent does best in dry sandy soils ),igure ;*.

,igure


5/27

yellow toadflax )Linaria vulgaris* and 7almatian toadflax )?. dalmatica* with the stem"mining weevil Mecinus

anthinus and yellow toadflax with the root" mining moth teobalea serratella ),igure /0*

field bindweed )Convolvulus arvensis* with the gall" forming mite (ceria malherbae

cleavers )Galium spurium* with the gall mite +ecidophyes rouhollahi

hound&s"tongue )Cynoglossum officinale* with the root weevil Mogulones cruciger

purple loosestrife )Lythrum salicaria* with foliage feeding beetles of the genus Balerucella

,igure A. centless chamomile )Matricaria perforata* with the seed weevil 5mphalapion hoo#eri

,igure @. %ladder campion )ilene vulgaris* with the foliage flower and seed"feeding tortoise beetle +assida a$urea

,igure /0. Cellow toadflax )?inaria vulgaris* with the stem" mining weevil )Mecinus anthinus*

#ansy )Tanacetum vulgare* is being evaluated as a possible candidate for biological control.Trials focusing on inundative biological control are also underway. The first pathogen to be registered as abioherbicide was the fungus +olletotrichum gloeosporioides f.sp malvae ),igure //* for control of round"leavedmallow )Malva pusilla* in field crops ),igure /2*. This bioherbicide was formerly licensed for commerciali$ation underthe tradename %ioMal. +urrently it is licensed to ncore Technologies ??+ with a tradename to be determined for

commercial release in the near future.5ther target weeds for inundative biological control are wild oat green foxtail +anada thistle cleavers and scentlesschamomile.


6/27

,igure /2. ?entils treated with +olletotrichum gloeosporioides f.sp. malvae )lower left* and the untreated control )lower right* three wee#s

after application.

How to obtain biological control agents,armers ranchers and landowners with any -uestions or an interest in obtaining these biological control agentsshould contact:

local provincial government crop specialist or extension agrologist

municipal agricultural fieldman

7r. (lec Mc+lay (lberta 8esearch +ouncil )Degreville* )


7/27

oil is a reservoir !or "any plant patho#ens and plants are under constant attac$ by these

soilborne or#anis"s% I! conditions beco"e !avorable !or in!ection, plants will develop

disease% Population levels o! soilborne patho#ens, includin# bacteria, !un#i,ne"atodes, and

so"e viruses can be reduced in the soil by appropriate treat"ents%

&earn which patho#ens attac$ the crop to be #rown% 'a"inethe crop re#ularly, at least

wee$ly, !or sy"pto"s o! disease or si#ns o! patho#ens% o "onitor !or root diseases, select

a !ew plants !ro" di!!erent locations and re"ove plants !ro" their containers or #ently

scrape or wash away soil% 'a"ine rootsand crowns !or brownin#, so!tness, or other early

indications o! disease% *lso loo$ !or discolored or wiltedplants and !un#al #rowths

above#round, which "ay indicate "ore advanced sta#es o! disease% est $its are available

!or detectin# Pythium, Rhizoctonia,and Phytophthora!un#i in!ectin# #reenhouse and

container+#rown nursery plants% owever, $eep in "ind that so"e test $its do not

speci!ically test !or patho#enic species- in such cases, nonpatho#ens could result in a !alse

positive result% .se test $its in co"bination with other in!or"ation to "a$e #ood pest

"ana#e"ent%

.nderstand the conditions and practices that pro"ote disease and re#ularly ea"ine !or and

re"edy disease+pro"otin# conditions and practices%Poor sanitation, inadeuate draina#e,

and i"proper irri#ationare the pri"ary conditions that pro"ote diseases o! roots%

Re"ove crop residueand old or low+uality plantsthat will not be "ar$eted%

Soil Solarization% In war"er cli"atic areas, solariationhas been e!!ective !or disin!estin#

containeried soil or #rowin# "ediu" and soil in cold !ra"es, as well as soil in open !ields%

1or soil in containers, "onitor the te"peratures o! the #rowin# "ediu" closely to ensure

that it is hi#h enou#h to control pests by placin# a soil ther"o"eter into the center o! the

"ass o! the soil "i% Plantin# "edia can be solaried either in ba#s or !lats covered with

transparent plastic or in layers 3+ to 9+inches wide sandwiched between two sheets o!

plastic% * double layer o! plastic can increase soil te"perature by up to 201% In war"er

areas o! 4ali!ornia, soil inside blac$ plastic sleeves can reach 5261 (704) durin#

solariation, euivalent to tar#et te"peratures !or soil disin!estation by aerated stea"% *t

this te"perature, soil is e!!ectively solaried within 30 "inutes% *t 5801 (04), soil is

solaried in 5 hour%

In open !ields, soil is "ore easily covered with a sin#le layer o! plastic% oil te"peratures

will be lower ecept at the sur!ace, so plastic should be le!t in place !or 8 to wee$s% 1or

"ai"u" e!!ectiveness and treat"ent predictability, solarie open !ields only in war"er

cli"atic areas, unless previous testin# has #iven consistently desirable results% olariation

is acceptable !or or#anic production%

Heat% eatin# the soilis very e!!ective and has the advanta#e over che"ical treat"ent in

that the soil can be planted i""ediately a!ter coolin#% any plant patho#ens are $illed by

short eposures to hi#h te"peratures- however, eperience has shown that the soil

te"peratures should be "aintained !or approi"ately 30 "inutes% ost plant patho#ens

can be $illed by te"peratures o! 5801 (04) !or 30 "inutes- however, so"e viruses (as

well as weed seeds) "ay survive this treat"ent% (;here weed seeds are a proble", a
http://www.ipm.ucdavis.edu/PMG/P/N-LS-PPEN-AD.001.htmlhttp://www.ipm.ucdavis.edu/PMG/F/M-PE-FADV-AK.001.htmlhttp://www.ipm.ucdavis.edu/PMG/F/M-PE-FADV-JK.005.htmlhttp://www.ipm.ucdavis.edu/PMG/P/D-FL-PSPP-FO.004.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.008.htmlhttp://www.ipm.ucdavis.edu/PMG/L/W-LM-LMIN-IF.006.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-IR.007.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.025.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.002.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-NC-CULT-SR.010.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.037.htmlhttp://www.ipm.ucdavis.edu/PMG/P/N-LS-PPEN-AD.001.htmlhttp://www.ipm.ucdavis.edu/PMG/F/M-PE-FADV-AK.001.htmlhttp://www.ipm.ucdavis.edu/PMG/F/M-PE-FADV-JK.005.htmlhttp://www.ipm.ucdavis.edu/PMG/P/D-FL-PSPP-FO.004.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.008.htmlhttp://www.ipm.ucdavis.edu/PMG/L/W-LM-LMIN-IF.006.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-IR.007.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.025.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.002.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-NC-CULT-SR.010.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.037.html


8/27

hi#her treat"ent te"perature is reuired, but the tobacco "osaic virus and so"e

weed seeds still will not be $illed by the hi#her te"perature%)

*lthou#h pure stea"at sea level is at ?5?1 (5004), the te"perature at which stea" is

used to treat soil is usually about 5601 because o! air that is present in the stea" or in the

soil bein# treated% I! air is "ied with stea", the te"perature o! the stea"+air "iture can

be closely controlled, dependin# on the ratio o! air to stea"% It has been de"onstrated that

so"e diseases, such as Rhioctonia da"pin#+o!!, are "uch less severe in soil that has been

treated at 5801 rather than at 5601% 'perience will tell the #rower at @ust what

te"perature to treat soil% *s a startin# point try 5801 (04) !or 30 "inutes%

I! a ce"ent "ier is used to heat a bul$ uantity o! soil, #enerally it is not necessary to

introduce air into the stea" because a lar#e a"ount o! air is present in the "ier and the

te"perature can be controlled by si"ply re#ulatin# the !low o! stea"% 'pensive air blowers

are not reuired !or this "ethod%

tea" heatin# o! containers !illed with soil in vaults li$ewise "ay not reuire the

introduction o! air into the stea" to control the te"perature% owever, circulation within thevault to insure even distribution o! heat is i"portant% 4irculatin# !ans can be located within

or eternal to the vault and the stea" can be introduced into the recirculatin# air% &eave

space between the vaults and chec$ te"peratures throu#hout the vault to insure that there

is #ood circulation o! stea" air%

Soil Fumigants% he "ost use!ul soil !u"i#ants are "ethyl bro"ide and chloropicrin% (he

?007 4ritical .se 'e"ption list allows use o! "ethyl bro"ide !or "oderate+to+severe

patho#en in!estation%) *lthou#h re#istered !or use, "eta"+sodiu" (=apa"), and dao"et

(Aasa"id) are not very e!!ective !or controllin# "any soilborne patho#ens,

includin# Verticilliumand Fusarium oxysporum.1u"i#ants such as "ethyl bro"ide are a

source o! volatile or#anic co"pounds (=B4s) but are not reactive with other airconta"inants that !or" oone- "ethyl bro"ide depletes oone% 1u"i#ate only as a last

resort when other "ana#e"ent strate#ies have not been success!ul or are not available%

ethyl bro"ide is a #as at te"peratures over 801% It escapes rapidly !ro" soil i! not

applied under a #as+proo! cover% Polyethylene sheetin#is co""only used to con!ine "ethyl

bro"ide, althou#h the #as does slowly escape throu#h polyethylene% ethyl bro"ide is

probably the "ost versatile o! the soil !u"i#ants because o! its ability to di!!use rapidly

throu#h the soil and $ill "any $inds o! or#anis"s, weeds, and "any seeds% oil #enerally

can be planted in @ust a !ew days a!ter re"oval o! plastic covers, althou#h there are

eceptions% * !ew plants such asAllium spp%, carnations, and snapdra#ons are sensitive to

and "ay be da"a#ed by inor#anic bro"ide that re"ains in the soil !ollowin# !u"i#ation%

&eachin# the soil with water be!ore plantin# is help!ul in reducin# the a"ount o! bro"ide inthe rootin# area% ethyl bro"ide alone usually does not $ill all o! the "icrosclerotia

o!Verticillium dahliae,the !un#us that is the causal a#ent o! =erticilliu" wilt% ;hen this

!un#us occurs it is o!ten necessary to include chloropicrin in the !u"i#ant%

ethyl bro"ide "ay be in@ected by chisels i! the soil is covered i""ediately by plastic% It is

the only soil !u"i#ant that needs to be applied under plastic covers% his is a restricted use

"aterial and reuires a per"it !ro" the county a#ricultural co""issioner to be purchased
http://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.023.htmlhttp://www.ipm.ucdavis.edu/PMG/F/C-AP-FUMI-AR.010.htmlhttp://www.ipm.ucdavis.edu/PMG/C/S-FL-CULT-SA.023.htmlhttp://www.ipm.ucdavis.edu/PMG/F/C-AP-FUMI-AR.010.html


9/27

and/or applied% ;ith the i"pendin# loss o! "ethyl bro"ide as a re#istered !uni#ant,

research is bein# conducted to !ind viable alternatives because o! oone depletion concerns%

4hloropicrin (trichloronitro"ethane) "ust be in@ected into soil% It is the best !u"i#ant !or

controllin# Verticillium dahliae.It #enerally is co"bined with "ethyl bro"ide in various

"itures dependin# upon the or#anis"s in the soil% I! used alone, a water seal "ay be used

to con!ine the #as- however, the #as is very ob@ectionable and irritatin# (it is co""only

$nown as tear #as) and, i! not e!!ectively con!ined, it "ay dri!t to inhabited areas% his is a

restricted use "aterial and reuires a per"it !ro" the county a#ricultural co""issioner to

be purchased and/or applied%

Soil Fungicides% o"e !un#icides wor$ best i! incorporated be!ore plantin#% Bthers "ay be

incorporated or applied a!ter sowin# or plantin#% o"e soil !un#icides control a narrow

ran#e o! or#anis"s while others control a wide ran#e o! or#anis"s% o"e o! the narrow

ran#e che"icals are the "ost e!!ective in controllin# a speci!ic or#anis"% 4o"binations are

used to increase the nu"ber o! or#anis"s controlled%

1osetyl+*l (*liette) is active a#ainst Phytophthoraspecies and so"e Pythium species% It isapplied as a soil drench or as a !oliar spray but is "ore e!!ective as a !oliar spray% It is

absorbed by !olia#e and "oves into roots% It is used as a drench at 0%6 to 5% lb a%i%/5000

s !t usin# 0%2 to 5%2 pt water/s !t% *s a !oliar spray it is applied at ? to 8 lb a%i%/500 #al

water%

he active in#redient in oilGard is Gliocladium virens,a soilborne !un#us that under certain

conditions helps provide control o! PythiumandRhizoctonia!un#i%

Iprodione (4hipco ?059) is used at 0%? lb a%i%/500 #al water applied as a drench (5C? pt/s

!t) at seedin# or transplantin#% It is e!!ective a#ainst Rhioctonia da"pin#+o!!, clerotinia,

and #ray "old% o"e iprodione is absorbed by plant parts%

e!enoa" (ubdue a) is active a#ainst Pythium, Phytophthora, and downy "ildews but

is not e!!ective a#ainst patho#ens outside o! this #roup o! or#anis"s% his "aterial replaces

the !un#icide "etalayl% It is applied at plantin# as a drench and periodically therea!ter as

needed% e!enoa" is also available in a #ranular !or"ulation to use be!ore plantin#% It is

water+soluble and readily leached !ro" soil% It is absorbed by plant parts includin# roots-

"ove"ent in the plant is pri"arily in the yle"% .se o! this "aterial over a period o! ti"e

"ay lead to resistance%

P4DA (erraclor), also called uintoene, is very active a#ainst diseases caused

by Rhizoctonia solaniand Sclerotiniaspp% and is the best available "aterial !or southern wilt

caused by Sclerotium rolfsii.It is insoluble in water and "ust be thorou#hly "ied with soil

to reach its desired depth o! control% It wor$s throu#h vapor action and has #ood residual

action% It is inactive a#ainst Pythiumpatho#ens% It is used at 0%2 to 5 lb a%i%/5000 s !t and

"ied into the top ? inches o! soil !or control o! Rhioctonia da"pin#+o!!% Ger"ination o!

so"e seeds "ay be inhibited and s"all plants "ay be stunted by this !un#icide%

Streptomyces griseoviridis(ycostop) is a bio!un#icide reported to help control seed rot,

root and ste" rot, and wilt caused byAlternariaandPhomopsisin container+#rown


10/27

orna"entals% In the #reenhouse it "ay suppress Aotrytis #ray "olds and root rots

o! Pythium, Phytophthora,andRhizoctonia.

hiophanate+"ethyl (1un#o1lo, 4learyEs 333, Fyban, ystec, etc%) is #enerally applied a!ter

sowin#% It helps to control Rhioctonia diseases, cottony rot, hielaviopsis rots, and so"e

4ylindrocladiu" diseases% It is not e!!ective

a#ainst Pythiumspp%, Phytophthora spp%, Sclerotium rolfsii, otrytisspp%, or Fusariumspp%

It is used at 0%2 lb a%i% or less/500 #al water and applied as a drench or heavy spray (5+?

pt/s !t)% hiophanate+"ethyl is absorbed by plant parts eposed to the che"ical% Roots

"ay absorb the !un#icide (or its brea$down product carbendai"), which "oves in the

yle" to transpirin# leaves%

!richodermaspp% (Garden olutions, Root Guardian) is a biolo#ical !un#icide reported to

help provide control o! root diseases caused by Pythium, Rhizoctonia,and Fusariumin

nursery and #reenhouse crops% It is !or"ulated as a seed protectant, a soil drench, and as

#ranules%

ri!lu"iole (erraGuard) is a protectant !un#icide used as a cuttin# soa$, soil drench, !oliarspray, or throu#h che"i#ation !or control o!"ylindrocladiumspp% Its use is restricted to

enclosed co""ercial structures such as #reenhouses and shade houses%

Seed Treatments% Streptomyces griseoviridis(ycostop) is used as a seed treat"ent !or

da"pin#+o!! and early root rots !or orna"entals planted in !ields or #reenhouse% 4aptan and

thira" are also seed treat"ents- they are #enerally applied at rates o! 5 to 8 o/500 lb

seed, but they o!!er only a s"all de#ree o! protection%

aterials used !or bulb or cor" dips include thiabendaole (ertect), which controls

1usariu" basal rot and Penicilliu" blue "old%

Treatment of Containers and Equipment% ebris, soil, and plant "aterial clin# to

containers and euip"ent- thorou#hly wash euip"ent to re"ove all soil or plantin# "i

particles% eat treat"ent is e!!ective in $illin# the plant patho#ens that adhere to containers

or that are in the debris% ;here stea" is not available, hot water or solariation can be very

e!!ective% ost plastic can be treated with hot water at te"peratures that cause "ini"al

so!tenin#% he "ini"u" water te"perature should be 5801 (04) whenever possible%

reat"ent ti"e can be as short as 5 "inute% &on#er treat"ent ti"es are "ore reliable and

the container or euip"ent "ust reach at least 5801 (04)% 1or solariation, containers

should be "oistened, stac$ed, and placed beneath a double+layer tent% Incubate !or 30

"inutes at or above 5261 (704) or 5 hour at or above 5801 (04)%

odiu" hypochlorite (the active in#redient in bleach) is e!!ective in $illin# so"e types o!

!un#al spores and bacteria% It penetrates clin#in# soil and plant "aterial very poorly% It is

e!!ective only as a sur!ace disin!ectant, so containers, tools, etc% "ust be !ree o! soil and

plant "aterial and clean be!ore treat"ent% odiu" hypochlorite is #enerally used as a

sur!ace disin!ectant at 0%2H% o achieve this concentration o! sodiu" hypochlorite,

household bleach can be diluted 5 part bleach to 50 parts water% 1or $nown conta"inated

"aterials, a stron#er solution diluted 5 part bleach to 2 parts water (5H sodiu"

hypochlorite), "ay be "ore e!!ective in $illin# patho#ens% *llow the solution to be in contact


11/27


12/27

o 2. Micro"organisms

2../ %acteria

2..2 ,ungi

2.. Diruses

o 2.4 +ombined use of parasitoids and pathogens

o 2.1 6lants

o 2.; !ndirect control

ffects of biological control

o ./ ffects on native biodiversity

o .2 ffects on invasive species

4 Brower education

1 ee also

; 8eferences

< ,urther reading

A xternal lin#s

Types of biological pest controlGeditH

There are three basic types of biological pest control strategies: importation )sometimes called

classical biological control* augmentation and conservation. G2H

ImportationGeditH

!mportation )or 'classical biological control'* involves the introduction of a pest&s natural enemies to a

new locale where they do not occur naturally. This is usually done by government authorities. !nmany instances the complex of natural enemies associated with a pest may be inade-uate a

situation that can occur when a pest is accidentally introduced into a new geographic area without

its associated natural enemies. These introduced pests are referred to as exotic pests and comprise

about 40I of the insect pests in the United tates.Gcitation neededH

The process of importation involves determining the origin of the introduced pest and then collecting

appropriate natural enemies associated with the pest or closely related species. elected natural
http://en.wikipedia.org/wiki/Biological_pest_control#Micro-organismshttp://en.wikipedia.org/wiki/Biological_pest_control#Bacteriahttp://en.wikipedia.org/wiki/Biological_pest_control#Fungihttp://en.wikipedia.org/wiki/Biological_pest_control#Viruseshttp://en.wikipedia.org/wiki/Biological_pest_control#Combined_use_of_parasitoids_and_pathogenshttp://en.wikipedia.org/wiki/Biological_pest_control#Plantshttp://en.wikipedia.org/wiki/Biological_pest_control#Indirect_controlhttp://en.wikipedia.org/wiki/Biological_pest_control#Effects_of_biological_controlhttp://en.wikipedia.org/wiki/Biological_pest_control#Effects_on_native_biodiversityhttp://en.wikipedia.org/wiki/Biological_pest_control#Effects_on_invasive_specieshttp://en.wikipedia.org/wiki/Biological_pest_control#Grower_educationhttp://en.wikipedia.org/wiki/Biological_pest_control#See_alsohttp://en.wikipedia.org/wiki/Biological_pest_control#Referenceshttp://en.wikipedia.org/wiki/Biological_pest_control#Further_readinghttp://en.wikipedia.org/wiki/Biological_pest_control#External_linkshttp://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=1http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-2http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=2http://en.wikipedia.org/wiki/United_Stateshttp://en.wikipedia.org/wiki/United_Stateshttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Biological_pest_control#Micro-organismshttp://en.wikipedia.org/wiki/Biological_pest_control#Bacteriahttp://en.wikipedia.org/wiki/Biological_pest_control#Fungihttp://en.wikipedia.org/wiki/Biological_pest_control#Viruseshttp://en.wikipedia.org/wiki/Biological_pest_control#Combined_use_of_parasitoids_and_pathogenshttp://en.wikipedia.org/wiki/Biological_pest_control#Plantshttp://en.wikipedia.org/wiki/Biological_pest_control#Indirect_controlhttp://en.wikipedia.org/wiki/Biological_pest_control#Effects_of_biological_controlhttp://en.wikipedia.org/wiki/Biological_pest_control#Effects_on_native_biodiversityhttp://en.wikipedia.org/wiki/Biological_pest_control#Effects_on_invasive_specieshttp://en.wikipedia.org/wiki/Biological_pest_control#Grower_educationhttp://en.wikipedia.org/wiki/Biological_pest_control#See_alsohttp://en.wikipedia.org/wiki/Biological_pest_control#Referenceshttp://en.wikipedia.org/wiki/Biological_pest_control#Further_readinghttp://en.wikipedia.org/wiki/Biological_pest_control#External_linkshttp://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=1http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-2http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=2http://en.wikipedia.org/wiki/United_Stateshttp://en.wikipedia.org/wiki/Wikipedia:Citation_needed


13/27

enemies are then passed through a rigorous assessment testing and -uarantineprocess to ensure

that they will wor# and that no unwanted organisms )such as hyperparasitoids* are introduced. !f

these procedures are passed the selected natural enemies are mass"produced and then released.

,ollow"up studies are conducted to determine if the natural enemy becomes successfully

established at the site of release and to assess the long"term benefit of its presence. Gcitation neededH

To be most effective at controlling a pest a biological control agent re-uires a coloni$ing ability

which will allow it to #eep pace with the spatial and temporal disruption of the habitat. !ts control of

the pest will also be greatest if it has temporal persistence so that it can maintain its population even

in the temporary absence of the target species and if it is an opportunistic forager enabling it to

rapidly exploit a pest population.GHowever an agent with such attributes is li#ely to be non"host

specific which is not ideal when considering its overall ecological impact as it may have unintended

effects on non"target organisms.Gcitation neededH

There are many examples of successful importation programs including:

Eoseph 3eedhamnoted a +hinese text dating from 04(7 &ecords of the 'lants and Treesof the (outhern &egions by si an which describes mandarin oranges protected by biologicalpest control techni-ues that are still in use today.

5ne of the earliest successes in the west was in controlling )cerya purchasi the cottony

cushion scale a pest that was devastating the+aliforniacitrus industry in the late /@th century.( predatory insect &odolia cardinalis)the Dedalia %eetle* and a parasitoid fly were introducedfrom (ustralia by+harles Dalentine 8iley. 9ithin a few years the cottony cushion scale wascompletely controlled by these introduced natural enemies.

7amage from*ypera posticaByllenhal the alfalfa weevil a serious introduced pest of

forage was substantially reduced by the introduction of several natural enemies. 20 years after

their introduction the population ofweevilsin the alfalfaarea treated for alfalfa weevil inthe 3ortheastern United tateswas reduced by


14/27

AugmentationGeditH

(ugmentation involves the supplemental release of natural enemies boosting the naturally occurring

population. 8elatively few natural enemies may be released at a critical time of the season

)inoculative release* or millions may be released )inundative release*. (n example of inoculative

release occurs in greenhouse production of several crops. 6eriodic releases of theparasitoidEncarsia formosa are used to control greenhouse whiteflyand the predatory

mite 'hytoseiulus persimilisis used for control of the two"spotted spider mite. ?ady beetles

lacewings or parasitoids such as those from the genusTrichogrammaare fre-uently released in

large numbers )inundative release*. 8ecommended release rates for Trichogramma in vegetable or

field crops range from 1000 to 200000 per acre )/ to 10 per s-uare metre* per wee# depending on

level of pest infestation. imilarly entomopathogenic nematodesare released at rates of millions

and even billions per acre for control of certain soil"dwelling insect pests.

ippodamia convergens the convergent lady beetle is commonly sold for biological control ofaphids.

The spraying of octopamine analogues)such as",M+* has been suggested as a way to boost the

effectiveness of augmentation.Gcitation neededH

5ctopamine regarded as the invertebratecounterpartof dopamineplays a role in activating the insects& flight"or"fight response. The idea behind using

octopamine analogues to augment biological control is that natural enemies will be more effective in

their eradication of the pest since the pest will be behaving in an unnatural way because its flight"or"

fight mechanism has been activated.Gclarification neededH5ctopamine analogues are purported to have two

desirable characteristics for this type of application: )/* they affect insects at very low dosages )2*

they do not have a physiological effect in humans )or other vertebrates*. G4HGdubious,discussH

ConservationGeditH

The conservation of existing natural enemies in an environment is the third method of biological pest

control. 3atural enemies are already adapted to the habitatand to the target pest and theirconservation can be simple and cost"effective. ?acewingslady beetleshover flylarvae and

parasiti$ed aphidmummies are almost always present in aphid colonies.
http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=3http://en.wikipedia.org/wiki/Encarsia_formosahttp://en.wikipedia.org/wiki/Encarsia_formosahttp://en.wikipedia.org/wiki/Whiteflyhttp://en.wikipedia.org/wiki/Whiteflyhttp://en.wikipedia.org/wiki/Phytoseiulus_persimilishttp://en.wikipedia.org/wiki/Trichogrammahttp://en.wikipedia.org/wiki/Trichogrammahttp://en.wikipedia.org/wiki/Nematodeshttp://en.wikipedia.org/wiki/Hippodamia_convergenshttp://en.wikipedia.org/wiki/Aphidshttp://en.wikipedia.org/wiki/Aphidshttp://en.wikipedia.org/wiki/Octopamine_analogueshttp://en.wikipedia.org/wiki/3-FMChttp://en.wikipedia.org/wiki/3-FMChttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Octopaminehttp://en.wikipedia.org/wiki/Invertebratehttp://en.wikipedia.org/wiki/Dopaminehttp://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-4http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-4http://en.wikipedia.org/wiki/Wikipedia:Disputed_statementhttp://en.wikipedia.org/wiki/Wikipedia:Disputed_statementhttp://en.wikipedia.org/wiki/Talk:Biological_pest_control#Dubioushttp://en.wikipedia.org/wiki/Talk:Biological_pest_control#Dubioushttp://en.wikipedia.org/wiki/Talk:Biological_pest_control#Dubioushttp://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=4http://en.wikipedia.org/wiki/Habitathttp://en.wikipedia.org/wiki/Lacewinghttp://en.wikipedia.org/wiki/Lady_beetlehttp://en.wikipedia.org/wiki/Lady_beetlehttp://en.wikipedia.org/wiki/Hover_flyhttp://en.wikipedia.org/wiki/Hover_flyhttp://en.wikipedia.org/wiki/Hover_flyhttp://en.wikipedia.org/wiki/Aphidhttp://en.wikipedia.org/wiki/Aphidhttp://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=3http://en.wikipedia.org/wiki/Encarsia_formosahttp://en.wikipedia.org/wiki/Whiteflyhttp://en.wikipedia.org/wiki/Phytoseiulus_persimilishttp://en.wikipedia.org/wiki/Trichogrammahttp://en.wikipedia.org/wiki/Nematodeshttp://en.wikipedia.org/wiki/Hippodamia_convergenshttp://en.wikipedia.org/wiki/Aphidshttp://en.wikipedia.org/wiki/Octopamine_analogueshttp://en.wikipedia.org/wiki/3-FMChttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Octopaminehttp://en.wikipedia.org/wiki/Invertebratehttp://en.wikipedia.org/wiki/Dopaminehttp://en.wikipedia.org/wiki/Wikipedia:Please_clarifyhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-4http://en.wikipedia.org/wiki/Wikipedia:Disputed_statementhttp://en.wikipedia.org/wiki/Talk:Biological_pest_control#Dubioushttp://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=4http://en.wikipedia.org/wiki/Habitathttp://en.wikipedia.org/wiki/Lacewinghttp://en.wikipedia.org/wiki/Lady_beetlehttp://en.wikipedia.org/wiki/Hover_flyhttp://en.wikipedia.org/wiki/Aphid


15/27

( turnaround flowerpot filled with straw to attract7ermaptera"species

+ropping systems can be modified to favor the natural enemies a practice sometimes referred to as

habitat manipulation. 6roviding a suitable habitat such as a shelterbelt hedgerow or beetle

ban#where beneficial insects can live and reproduce can help ensure the survival of populations of

natural enemies. Things as simple as leaving a layer of fallen down leaves or mulch in place

provides a suitable food source for worms and provides a shelter for small insects in turn also

providing a food source for hedgehogsandshrew mice.+ompost pile)s* and containers for ma#ing

leaf compost also provide shelter as long as they are accessible by the animals )not fully closed*. (

stac# of wood may provide a shelter for voleshedgehogs shrew mice some species of

butterflies ... ?ong grass andpondsprovide shelters for frogs and toads )which themselves eat

snails*. 3ot cutting any annual or other non"hardy plants before winter )but instead in spring* allows

many insects to ma#e use of their hollow stems during winter.G1H!n +alifornia prune trees aresometimes planted in grape vineyards to provide an improved overwintering habitat or refuge for a

#ey grape pest parasitoid. The prune trees harbor an alternate host for the parasitoid which could

previously overwinter only at great distances from most vineyards. The provisioning of artificial

shelters in the form of wooden cas#ets boxesor flowerpotsis also sometimes underta#en

particularly in gardens to ma#e a cropped area more attractive to natural enemies. ,or example the

stimulation of the natural predator!ermapterais done in gardens by hanging upside"

down flowerpotsfilled with strawor wood wool. Breen lacewings are given housing by using plastic

bottles with an open bottom and a roll of cardboard inside of it.G1H%irdhouses provide housing for

birds some of whom eat certain pests. (ttracting the most useful birds can be done by using a

correct diameter opening in the birdhouse )ust large enough for the specific species of bird that

needs to be attracted to fit through but not other species of birds*.

%esides the provisioning of natural or artificial housing the providing of nectar"rich plants is also

beneficial. 5ften many species of plants are used so as to provide food for many natural predators

and this for a long period of time )this is done by using different types of plants as each species only

blooms for a short period*. !t should be mentioned that many natural predators are nectivorous

during the adult stage but parasitic or predatory as larvae. ( good example of this is the soldier

beetle which is fre-uently found on flowers as an adult but whose larvae eat aphids caterpillars
http://en.wikipedia.org/wiki/Dermapterahttp://en.wikipedia.org/wiki/Dermapterahttp://en.wikipedia.org/wiki/Dermapterahttp://en.wikipedia.org/wiki/Windbreakhttp://en.wikipedia.org/wiki/Hedgerowhttp://en.wikipedia.org/wiki/Beetle_bankhttp://en.wikipedia.org/wiki/Beetle_bankhttp://en.wikipedia.org/wiki/Hedgehoghttp://en.wikipedia.org/wiki/Hedgehoghttp://en.wikipedia.org/wiki/Shrewhttp://en.wikipedia.org/wiki/Shrewhttp://en.wikipedia.org/wiki/Compost_pilehttp://en.wikipedia.org/wiki/Compost_pilehttp://en.wikipedia.org/wiki/Volehttp://en.wikipedia.org/wiki/Volehttp://en.wikipedia.org/wiki/Pondhttp://en.wikipedia.org/wiki/Pondhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-ReferenceA-5http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-ReferenceA-5http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-ReferenceA-5http://en.wikipedia.org/wiki/Boxhttp://en.wikipedia.org/wiki/Flowerpothttp://en.wikipedia.org/wiki/Dermapterahttp://en.wikipedia.org/wiki/Dermapterahttp://en.wikipedia.org/wiki/Flowerpothttp://en.wikipedia.org/wiki/Strawhttp://en.wikipedia.org/wiki/Wood_woolhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-ReferenceA-5http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-ReferenceA-5http://en.wikipedia.org/wiki/Dermapterahttp://en.wikipedia.org/wiki/Windbreakhttp://en.wikipedia.org/wiki/Hedgerowhttp://en.wikipedia.org/wiki/Beetle_bankhttp://en.wikipedia.org/wiki/Beetle_bankhttp://en.wikipedia.org/wiki/Hedgehoghttp://en.wikipedia.org/wiki/Shrewhttp://en.wikipedia.org/wiki/Compost_pilehttp://en.wikipedia.org/wiki/Volehttp://en.wikipedia.org/wiki/Pondhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-ReferenceA-5http://en.wikipedia.org/wiki/Boxhttp://en.wikipedia.org/wiki/Flowerpothttp://en.wikipedia.org/wiki/Dermapterahttp://en.wikipedia.org/wiki/Flowerpothttp://en.wikipedia.org/wiki/Strawhttp://en.wikipedia.org/wiki/Wood_woolhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-ReferenceA-5


16/27

grasshopper eggs and other beetles. ?etting certain plants )as elianthus spp 8udbec#ia spp

7ipsacus spp chinacea spp* come into seed is also advised to supply food for birds. aving some

trees or shrubs in place that carry berries is also practiced and provide a source of food for birds.

5ften treesJshrubs are used that do not produce berries fit for human consumption avoiding food

competition. xamples are orbus spp (melanchier spp +rataegus spp ambucus nigra !lex

a-uifolium 8hamnus frangula. 5bviously for this to wor# these trees can not be prunedJtrimmeduntil after the birds and other animals have eaten all of the berries.

(lso the providing of host plants)plants on which organisms can lay their eggs* may also be

necessairy. These organisms for which host plants can be foreseen can be certain natural predators

caterpillars and even a limited amount of host plants for pests can be tolerated. The latter ensures

that natural predators remain in the vicinity and tolerating a certain amount of loss to pests would be

needed anyhow since no chemical pesticides can be used )organic pesticides can be used but often

can on itself not eliminate all pests during an infestation*. This as natural predators are susceptible

to the same pesticidesused to target pests. 6lants for caterpillars are optional and only ensure that

sufficient amounts of moths are produced which form a source of food to bats. %ats may be wanted

as they also consume large amounts of mos-uitoes which despite not targeting any plants can stillbe a nuisance to people in areas where there is much standing water nearby )i.e. pond cree# ...*.

+onservation strategies such as mixed plantings and the provision of flowering borders can be more

difficult to accommodate in large"scale crop production. There may also be some conflict with pest

control for the large producer because of the difficulty of targeting the pest species also refuges

may be utilised by the pest insects as well as by natural enemies. ome plants that are attractive to

natural enemies may also be hosts for certain plant diseases especially plant viruses that could be

vectored by insect pests to the crop.

Biological control agentsGeditH

PredatorsGeditH

?acewingsare available from biocontrol dealers.
http://en.wikipedia.org/wiki/Host_(biology)http://en.wikipedia.org/wiki/Pesticidehttp://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=5http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=6http://en.wikipedia.org/wiki/Chrysopidaehttp://en.wikipedia.org/wiki/Chrysopidaehttp://en.wikipedia.org/wiki/Host_(biology)http://en.wikipedia.org/wiki/Pesticidehttp://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=5http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=6http://en.wikipedia.org/wiki/Chrysopidae


17/27

6redators are mainly free"living species that directly consume a large number of preyduring their

whole lifetime.

?adybugs and in particular their larvae which are active between May and Euly in the northern

hemisphere are voracious predators ofaphids and will also consume mitesscale insectsand

smallcaterpillars.

The larvae of many hoverflyspecies principally feed upon greenfly one larva devouring up to fifty a

day or /000 in its lifetime. They also eat fruit treespider mitesand small caterpillars. (dults feed on

nectar andpollen which they re-uire for egg production.

6redatory6olisteswasploo#ing for bollworms or other caterpillarson a cotton plant

7ragonfliesare important predators of mos-uitoes both in the water where the

dragonfly naiadseatmos-uitolarvae and in the air where adult dragonflies capture and eat adult

mos-uitoes. +ommunity"wide mos-uito control programs that spray adult mos-uitoes also #ill

dragonflies thus reducing an important biocontrol agent.

everal species of entomopathogenic nematodeare important predators of insect pests.G;H'hasmarhabditis hermaphroditais a microscopic nematodethat #ills slugs thereafter feeding and

reproducing inside. The nematode is applied by watering onto moist soil and gives protection for up

to six wee#s in optimum conditions.

5ther useful garden predators include lacewingspirate bugs rove and ground beetles aphid

midgecentipedesspiders predatory mites as well as larger fauna such

as frogstoads li$ards hedgehogsslow"wormsand birds. +ats and rat terriers #ill field mice rats

Eune bugs and birds.7achshundsare bred specifically to fit inside tunnels underground to

#ill badgers.

More examples:

'hytoseiulus persimilis)against spider mites*

Amblyseius californicus)against spider mites*
http://en.wikipedia.org/wiki/Preyhttp://en.wikipedia.org/wiki/Ladybugshttp://en.wikipedia.org/wiki/Aphidhttp://en.wikipedia.org/wiki/Miteshttp://en.wikipedia.org/wiki/Miteshttp://en.wikipedia.org/wiki/Scale_insecthttp://en.wikipedia.org/wiki/Scale_insecthttp://en.wikipedia.org/wiki/Caterpillarhttp://en.wikipedia.org/wiki/Caterpillarhttp://en.wikipedia.org/wiki/Caterpillarhttp://en.wikipedia.org/wiki/Hoverflyhttp://en.wikipedia.org/wiki/Spider_mitehttp://en.wikipedia.org/wiki/Spider_mitehttp://en.wikipedia.org/wiki/Pollenhttp://en.wikipedia.org/wiki/Pollenhttp://en.wikipedia.org/wiki/Predatorhttp://en.wikipedia.org/wiki/Predatorhttp://en.wikipedia.org/wiki/Paper_wasphttp://en.wikipedia.org/wiki/Paper_wasphttp://en.wikipedia.org/wiki/Vespidhttp://en.wikipedia.org/wiki/Vespidhttp://en.wikipedia.org/wiki/Caterpillarhttp://en.wikipedia.org/wiki/Caterpillarhttp://en.wikipedia.org/wiki/Dragonflyhttp://en.wikipedia.org/wiki/Nymph_(biology)http://en.wikipedia.org/wiki/Mosquitohttp://en.wikipedia.org/wiki/Mosquitohttp://en.wikipedia.org/wiki/Larvahttp://en.wikipedia.org/wiki/Entomopathogenic_nematodehttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-6http://en.wikipedia.org/wiki/Phasmarhabditis_hermaphroditahttp://en.wikipedia.org/wiki/Nematodehttp://en.wikipedia.org/wiki/Chrysopidaehttp://en.wikipedia.org/wiki/Chrysopidaehttp://en.wikipedia.org/wiki/Anthocoridaehttp://en.wikipedia.org/wiki/Aphidoletes_aphidomyzahttp://en.wikipedia.org/wiki/Aphidoletes_aphidomyzahttp://en.wikipedia.org/wiki/Centipedehttp://en.wikipedia.org/wiki/Centipedehttp://en.wikipedia.org/wiki/Centipedehttp://en.wikipedia.org/wiki/Spiderhttp://en.wikipedia.org/w/index.php?title=Predatory_mite&action=edit&redlink=1http://en.wikipedia.org/wiki/Froghttp://en.wikipedia.org/wiki/Froghttp://en.wikipedia.org/wiki/Toadhttp://en.wikipedia.org/wiki/Lizardhttp://en.wikipedia.org/wiki/Hedgehoghttp://en.wikipedia.org/wiki/Slow-wormhttp://en.wikipedia.org/wiki/Slow-wormhttp://en.wikipedia.org/wiki/Dachshundhttp://en.wikipedia.org/wiki/Dachshundhttp://en.wikipedia.org/wiki/Badgershttp://en.wikipedia.org/wiki/Phytoseiulus_persimilishttp://en.wikipedia.org/wiki/Phytoseiulus_persimilishttp://en.wikipedia.org/w/index.php?title=Amblyseius_californicus&action=edit&redlink=1http://en.wikipedia.org/wiki/Preyhttp://en.wikipedia.org/wiki/Ladybugshttp://en.wikipedia.org/wiki/Aphidhttp://en.wikipedia.org/wiki/Miteshttp://en.wikipedia.org/wiki/Scale_insecthttp://en.wikipedia.org/wiki/Caterpillarhttp://en.wikipedia.org/wiki/Hoverflyhttp://en.wikipedia.org/wiki/Spider_mitehttp://en.wikipedia.org/wiki/Pollenhttp://en.wikipedia.org/wiki/Predatorhttp://en.wikipedia.org/wiki/Paper_wasphttp://en.wikipedia.org/wiki/Vespidhttp://en.wikipedia.org/wiki/Caterpillarhttp://en.wikipedia.org/wiki/Dragonflyhttp://en.wikipedia.org/wiki/Nymph_(biology)http://en.wikipedia.org/wiki/Mosquitohttp://en.wikipedia.org/wiki/Larvahttp://en.wikipedia.org/wiki/Entomopathogenic_nematodehttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-6http://en.wikipedia.org/wiki/Phasmarhabditis_hermaphroditahttp://en.wikipedia.org/wiki/Nematodehttp://en.wikipedia.org/wiki/Chrysopidaehttp://en.wikipedia.org/wiki/Anthocoridaehttp://en.wikipedia.org/wiki/Aphidoletes_aphidomyzahttp://en.wikipedia.org/wiki/Aphidoletes_aphidomyzahttp://en.wikipedia.org/wiki/Centipedehttp://en.wikipedia.org/wiki/Spiderhttp://en.wikipedia.org/w/index.php?title=Predatory_mite&action=edit&redlink=1http://en.wikipedia.org/wiki/Froghttp://en.wikipedia.org/wiki/Toadhttp://en.wikipedia.org/wiki/Lizardhttp://en.wikipedia.org/wiki/Hedgehoghttp://en.wikipedia.org/wiki/Slow-wormhttp://en.wikipedia.org/wiki/Dachshundhttp://en.wikipedia.org/wiki/Badgershttp://en.wikipedia.org/wiki/Phytoseiulus_persimilishttp://en.wikipedia.org/w/index.php?title=Amblyseius_californicus&action=edit&redlink=1


18/27

Amblyseius cucumeris)against spider mites*G


19/27

7iagram illustrating the life cycles of Breenhouse whitefly and its parasitoid wasp ncarsia formosa

Encarsia formosa( small predatory chalcid waspwhich is a parasitoid of whitefly a sap"

feeding insect which can cause wilting andblac# sooty moulds. !t is most effective when dealingwith low level infestations giving protection over a long period of time. The wasp lays its eggs inyoung whitefly &scales& turning them blac# as the parasite larvae pupates.

Eretmocerusspp. )against white flies*GAH

Aphidius colemani)against aphids*

Gonatocerus ashmeadi)ymenoptera: Mymaridae* has been introduced to control

the glassy"winged sharpshooter*omalodisca vitripennis)emipterae: +icadellidae* in,rench6olynesiaand has successfully controlled @1I of the pest density.G@H

6arasitoids are one of the most widely used biological control agents. +ommercially there are twotypes of rearing systems: short"term daily output with high production of parasitoids per day and

long"term low daily output with a range in production of 4"/000million female parasitoids per wee#.G/0H?arger production facilities produce on a yearlong basis whereas some facilities will produce only

seasonally.

8earing facilities are usually a significant distance from where the agents will be used in the field

and transporting the parasitoids from the point of production to the point of use can pose problems.

hipping conditions can be too hot and even vibrations from planes or truc#s can disrupt the

parasitoids.G/0H

$icro%organismsGeditHFurther informationbiopesticide

6athogenic micro"organisms include bacteriafungiandviruses. They #ill or debilitate their host and

are relatively host"specific. Dariousmicrobialinsect diseases occur naturally but may also be used

asbiological pesticides. 9hen naturally occurring these outbrea#s are density"dependent in that

they generally only occur as insect populations become denser.
http://en.wikipedia.org/wiki/Encarsia_formosahttp://en.wikipedia.org/wiki/Encarsia_formosahttp://en.wikipedia.org/wiki/Chalcid_wasphttp://en.wikipedia.org/wiki/Whiteflyhttp://en.wikipedia.org/wiki/Sooty_Moldhttp://en.wikipedia.org/w/index.php?title=Eretmocerus&action=edit&redlink=1http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-8http://en.wikipedia.org/w/index.php?title=Aphidius_colemani&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Aphidius_colemani&action=edit&redlink=1http://en.wikipedia.org/wiki/Hymenopterahttp://en.wikipedia.org/wiki/Mymaridaehttp://en.wikipedia.org/wiki/Glassy-winged_sharpshooterhttp://en.wikipedia.org/wiki/Homalodisca_vitripennishttp://en.wikipedia.org/wiki/Homalodisca_vitripennishttp://en.wikipedia.org/wiki/Homalodisca_vitripennishttp://en.wikipedia.org/wiki/French_Polynesiahttp://en.wikipedia.org/wiki/French_Polynesiahttp://en.wikipedia.org/wiki/French_Polynesiahttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-9http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-9http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-smith-10http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-smith-10http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=8http://en.wikipedia.org/wiki/Biopesticidehttp://en.wikipedia.org/wiki/Biopesticidehttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Fungihttp://en.wikipedia.org/wiki/Fungihttp://en.wikipedia.org/wiki/Fungihttp://en.wikipedia.org/wiki/Viruseshttp://en.wikipedia.org/wiki/Viruseshttp://en.wikipedia.org/wiki/Microbialhttp://en.wikipedia.org/wiki/Microbialhttp://en.wikipedia.org/wiki/Biological_pesticidehttp://en.wikipedia.org/wiki/Encarsia_formosahttp://en.wikipedia.org/wiki/Encarsia_formosahttp://en.wikipedia.org/wiki/Chalcid_wasphttp://en.wikipedia.org/wiki/Whiteflyhttp://en.wikipedia.org/wiki/Sooty_Moldhttp://en.wikipedia.org/w/index.php?title=Eretmocerus&action=edit&redlink=1http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-8http://en.wikipedia.org/w/index.php?title=Aphidius_colemani&action=edit&redlink=1http://en.wikipedia.org/wiki/Hymenopterahttp://en.wikipedia.org/wiki/Mymaridaehttp://en.wikipedia.org/wiki/Glassy-winged_sharpshooterhttp://en.wikipedia.org/wiki/Homalodisca_vitripennishttp://en.wikipedia.org/wiki/French_Polynesiahttp://en.wikipedia.org/wiki/French_Polynesiahttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-9http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-smith-10http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-smith-10http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=8http://en.wikipedia.org/wiki/Biopesticidehttp://en.wikipedia.org/wiki/Bacteriahttp://en.wikipedia.org/wiki/Fungihttp://en.wikipedia.org/wiki/Viruseshttp://en.wikipedia.org/wiki/Microbialhttp://en.wikipedia.org/wiki/Biological_pesticide


20/27

Bacteriaedit/

%acteria used for biological control infect insects via their digestive tracts so insects with suc#ing

mouth parts li#e aphids and scale insects are difficult to control with bacterial biological control.G//H0acillus thuringiensisis the most widely applied species of bacteria used for biological control

with at least four sub"species used to control ?epidopteran)mothbutterfly* +oleopteran)beetle*and7ipteran)true flies* insect pests. The bacteria is available in sachets of dried spores which are

mixed with water and sprayed onto vulnerable plants such asbrassicasandfruit trees.%acillus

thuringiensis has also been incorporated into crops ma#ing them resistant to these pests and thus

reducing the use of pesticides.

Fungiedit/

,ungi that cause disease in insects are #nown as entomopathogenic fungi including at least

fourteen species that attac# aphids.G/2H0eauveria bassianais used to manage a wide variety of insect

pests including: whiteflies thrips aphids and weevils. ( remar#able additional feature of some fungi

is their effect on plant fitness. Trichodermaspecies may enhance biomass production promoting rootdevelopment dissolving insoluble phosphate containing minerals. Gcitation neededH

xamples of entomopathogenic fungi:

0eauveria bassiana)against white fliesthrips aphids and weevils*

'aecilomyces fumosoroseus)against white flies thripsand aphids*

Metarhi1iumspp. )against beetles locusts and grasshoppersemiptera spider mitesand

other pests*

Lecanicilliumspp. )against white flies thrips and aphids*

Cordycepsspecies )includesteleomorphsof the above genera: that infect a wide spectrum

of arthropods*

Trichodermaspecies are used to manage certain plant pathogens. Trichoderma viridehas

been used against 7utch lm disease and to treat the spread of fungal and bacterial growth ontree wounds. !t may also have potential as a means of combatingsilver leaf disease.

everal members of +hytridiomycotaand%lastocladiomycotahave been explored as agents of

biological control. ,rom+hytridiomycota(ynchytrium solstitialeis being considered as a control

agent of theyellow star thistle )Centaurea solstitialis*in the United tates.G/H(ynchytrium

minutumoccasionally parasiti$es#ud$uand was considered as a control agent against this weed

outside of its native range but (. minutumparasiti$es agricultural crop plants more fre-uently than it

parasiti$es #ud$u.G/4H%atrachochytrium dendrobatidiswas briefly considered and soundly reected as

a means of controlling invasive frog populations in awaii.G/1H,rom %lastocladiomycotacertain

members of+oelomomyceswere explored as possible agents of biological control of mos-uitoes.G/;H
http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=9http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=9http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=9http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-11http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-11http://en.wikipedia.org/wiki/Bacillus_thuringiensishttp://en.wikipedia.org/wiki/Bacillus_thuringiensishttp://en.wikipedia.org/wiki/Lepidopterahttp://en.wikipedia.org/wiki/Mothhttp://en.wikipedia.org/wiki/Mothhttp://en.wikipedia.org/wiki/Butterflyhttp://en.wikipedia.org/wiki/Coleopterahttp://en.wikipedia.org/wiki/Dipterahttp://en.wikipedia.org/wiki/Dipterahttp://en.wikipedia.org/wiki/Dipterahttp://en.wikipedia.org/wiki/Brassicahttp://en.wikipedia.org/wiki/Fruit_treehttp://en.wikipedia.org/wiki/Fruit_treehttp://en.wikipedia.org/wiki/Fruit_treehttp://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=10http://en.wikipedia.org/wiki/Entomopathogenic_fungihttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-12http://en.wikipedia.org/wiki/Beauveria_bassianahttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Entomopathogenic_fungihttp://en.wikipedia.org/wiki/Beauveria_bassianahttp://en.wikipedia.org/wiki/Beauveria_bassianahttp://en.wikipedia.org/wiki/Thriphttp://en.wikipedia.org/wiki/Thriphttp://en.wikipedia.org/wiki/Paecilomyces_fumosoroseushttp://en.wikipedia.org/wiki/Thriphttp://en.wikipedia.org/wiki/Metarhiziumhttp://en.wikipedia.org/wiki/Metarhiziumhttp://en.wikipedia.org/wiki/Hemipterahttp://en.wikipedia.org/wiki/Hemipterahttp://en.wikipedia.org/wiki/Spider_miteshttp://en.wikipedia.org/wiki/Spider_miteshttp://en.wikipedia.org/wiki/Lecanicilliumhttp://en.wikipedia.org/wiki/Cordycepshttp://en.wikipedia.org/wiki/Cordycepshttp://en.wikipedia.org/wiki/Teleomorphhttp://en.wikipedia.org/wiki/Teleomorphhttp://en.wikipedia.org/wiki/Teleomorphhttp://en.wikipedia.org/wiki/Trichodermahttp://en.wikipedia.org/wiki/Trichodermahttp://en.wikipedia.org/wiki/Dutch_Elm_diseasehttp://en.wikipedia.org/wiki/Chondrostereum_purpureumhttp://en.wikipedia.org/wiki/Chondrostereum_purpureumhttp://en.wikipedia.org/wiki/Chytridiomycotahttp://en.wikipedia.org/wiki/Chytridiomycotahttp://en.wikipedia.org/wiki/Blastocladiomycotahttp://en.wikipedia.org/wiki/Blastocladiomycotahttp://en.wikipedia.org/wiki/Chytridiomycotahttp://en.wikipedia.org/wiki/Chytridiomycotahttp://en.wikipedia.org/wiki/Synchytriumhttp://en.wikipedia.org/wiki/Synchytriumhttp://en.wikipedia.org/wiki/Centaurea_solstitialishttp://en.wikipedia.org/wiki/Centaurea_solstitialishttp://en.wikipedia.org/wiki/Centaurea_solstitialishttp://en.wikipedia.org/wiki/Centaurea_solstitialishttp://en.wikipedia.org/wiki/Centaurea_solstitialishttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Gleason-13http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Gleason-13http://en.wikipedia.org/wiki/Kudzuhttp://en.wikipedia.org/wiki/Kudzuhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Li-14http://en.wikipedia.org/wiki/Batrachochytrium_dendrobatidishttp://en.wikipedia.org/wiki/Batrachochytrium_dendrobatidishttp://en.wikipedia.org/wiki/Batrachochytrium_dendrobatidishttp://en.wikipedia.org/wiki/Hawaiihttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Frog-15http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Frog-15http://en.wikipedia.org/wiki/Blastocladiomycotahttp://en.wikipedia.org/wiki/Blastocladiomycotahttp://en.wikipedia.org/w/index.php?title=Coelomomyces&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Coelomomyces&action=edit&redlink=1http://en.wikipedia.org/wiki/Mosquitoeshttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Sparrow1960-16http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Sparrow1960-16http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=9http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-11http://en.wikipedia.org/wiki/Bacillus_thuringiensishttp://en.wikipedia.org/wiki/Lepidopterahttp://en.wikipedia.org/wiki/Mothhttp://en.wikipedia.org/wiki/Butterflyhttp://en.wikipedia.org/wiki/Coleopterahttp://en.wikipedia.org/wiki/Dipterahttp://en.wikipedia.org/wiki/Brassicahttp://en.wikipedia.org/wiki/Fruit_treehttp://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=10http://en.wikipedia.org/wiki/Entomopathogenic_fungihttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-12http://en.wikipedia.org/wiki/Beauveria_bassianahttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Entomopathogenic_fungihttp://en.wikipedia.org/wiki/Beauveria_bassianahttp://en.wikipedia.org/wiki/Thriphttp://en.wikipedia.org/wiki/Paecilomyces_fumosoroseushttp://en.wikipedia.org/wiki/Thriphttp://en.wikipedia.org/wiki/Metarhiziumhttp://en.wikipedia.org/wiki/Hemipterahttp://en.wikipedia.org/wiki/Spider_miteshttp://en.wikipedia.org/wiki/Lecanicilliumhttp://en.wikipedia.org/wiki/Cordycepshttp://en.wikipedia.org/wiki/Teleomorphhttp://en.wikipedia.org/wiki/Trichodermahttp://en.wikipedia.org/wiki/Dutch_Elm_diseasehttp://en.wikipedia.org/wiki/Chondrostereum_purpureumhttp://en.wikipedia.org/wiki/Chytridiomycotahttp://en.wikipedia.org/wiki/Blastocladiomycotahttp://en.wikipedia.org/wiki/Chytridiomycotahttp://en.wikipedia.org/wiki/Synchytriumhttp://en.wikipedia.org/wiki/Centaurea_solstitialishttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Gleason-13http://en.wikipedia.org/wiki/Kudzuhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Li-14http://en.wikipedia.org/wiki/Batrachochytrium_dendrobatidishttp://en.wikipedia.org/wiki/Hawaiihttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Frog-15http://en.wikipedia.org/wiki/Blastocladiomycotahttp://en.wikipedia.org/w/index.php?title=Coelomomyces&action=edit&redlink=1http://en.wikipedia.org/wiki/Mosquitoeshttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-Sparrow1960-16


21/27

Virusesedit/

The uropean 8abbit )+ryctolagus cuniculus* is seen as a maor pest in (ustralia and 3ew Nealand.

( viral biological control that can be introduced in order to control the overpopulationof uropean rabbitin (ustralia is the rabbit haemorrhagic disease virusthat causes therabbithaemorrhagic disease.

Combined use of parasitoids and pathogensGeditH

!n cases of massive and severe infection of invasive pests techni-ues of pest control are often used

in combination. (n example being that of theemerald ash borer)Agrilus planipennis,airmaire

family%uprestidae* an invasive beetlefrom+hina which has destroyed tens of millions ofash

treesin its introduced range in3orth (merica. (s part of the campaign against the emerald ash

borer )(%* (merican scientists in conunction with the +hinese (cademy of ,orestrysearched

since 200 for its natural enemies in the wild leading to the discovery of several parasitoid wasps

namely Tetrastichus planipennisi a gregarious larval endoparasitoid+obius agrili a solitaryparthenogenic egg parasitoid and (pathius agrili a gregarious larval ectoparasitoid. These have

been introduced and released into theUnited tates of (mericaas a possible biological control of the

emerald ash borer. !nitial results have shown promise with Tetrastichus planipennisiand it is now

being released along with 0eauveria bassianaa fungalpathogenwith #nown insecticidal properties.G/


22/27

breed. Therefore the(ustralian 7ung %eetle 6roect)/@;1K/@A1* led by 7r. Beorge %ornemiss$aof

the+ommonwealth cientific and !ndustrial 8esearch 5rganisation released forty"nine species

of dung beetleG22Hwith the aim of reducing the amount of dung and therefore also breeding sites of

the fly.G2H

Effects of biological controlGeditH&ffects on native biodiversityGeditH

The cane toad0ufo marinus

%iological control can potentially have positive and negative effects on biodiversity.GHThe most

common problems with biological control occur via predation parasitism pathogenicity competition

or other attac#s on non"target species. G24H5ften a biological control agent is imported into an area to

reduce the competitive advantage of an exotic speciesthat has previously invadedor

been introducedthere the aim being to thereby protect the existing native speciesand ecology.

owever the introduced control does not always target only the intended species> it can also target

native species.G21H!n awaii during the /@40s parasitic wasps were introduced to control a

lepidopteran pest and the wasps are still found there today. This may have a negative impact on the

native ecosystem however host range and impacts need to be studied before declaring their impacton the environment.G2;H

5ver the past /1 years with the rise in biological control interest there has become a greater focus

on the non"target impacts that could occur.GH!n the past many biological control releases were not

thoroughly examined and agents of biological control were released without any consideration.

9hen introducing a biological control agent to a new area a primary concern is its host"specificity.

Beneralist feeders )control agents that are not restricted to preying on a single species or a small

range of species* often ma#e poor biological control agents and may become invasive species

themselves. ,or this reason potential biological control agents should be subect to extensive testing

and-uarantinebefore release into any new environment. !f a species is introduced and attac#s a

native species the biodiversity in that area can change dramatically. 9hen one native species isremoved from an area it may have filled an essential ecological niche. 9hen this niche is absent it

may directly affect the entire ecosystem.Gcitation neededH

Dertebrate animals tend to be generalist feeders and seldom ma#e good biological control agents>

many of the classic cases of 'biocontrol gone awry' involve vertebrates. ,or example the cane

toad 0ufo marinuswas intentionally introduced to(ustraliato control the introduced ,rench&s +ane

%eetleand the Breybac# +ane %eetleG2


23/27

from awaiiand bred in captivity to increase their numbers until they were released into the sugar

cane fields of the tropic north in /@1. !t was later discovered that the toads could not ump very high

and so they could not eat the cane beetles which stayed up on the upper stal#s of the cane plants.

owever the toad thrived by feeding on other insects and it soon spread very rapidly> it too# over

native amphibianhabitatand brought foreign disease to nativetoadsandfrogs dramatically

reducing their populations. (lso when it is threatened or handled the cane toadreleasespoisonfromparotid glandson its shoulders> native (ustralian species such

as goannastiger sna#es dingosand northern -uollsthat attempted to eat the toad were harmed or

#illed.G2AHThis example shows how small mis"introduced organismscan alter the nativebiodiversityin

large ecosystems. !f native species are reduced or eradicated a domino effectcan ta#e place until a

new e-uilibriumis reached.

5ther examples of biological control agents that subse-uently crossed over to native species are:

&hinocyllus conicusa seed"feeding weevil was introduced to 3orth (merica to control

exoticthistles)Mus# and +anadian*. owever the weevil does not target only the exotic thistles>it also targets native thistles that are essential to various native insects which rely solely onnative thistles and do not adapt to other plant species.

The mongoosewas introduced to awaiiin order to control the ratpopulation. owever it

preyed on theendemic birds of awaii especially their eggs more often than it ate the rats.)3ote however that the introduction of the mongoose was not underta#en based on scientificOor perhaps anyOunderstanding of the conse-uences of such an action. The introduction of ageneralist mammal for biocontrol of anything would be unthin#able by any reasonable standardstoday.*

1 cats brought to the subantarctic6rince dward !slandsto catch mice in /@4@ multiplied to

400 in about two decades and started to threaten local extinction of birds. They had to beinfected withfeline distempervirus. The rest were shot and completely eliminated by the /@@0s.

The sturdy and prolific mos-uito fishwas introduced from around the Bulf of Mexico to

around the world in the /@0s and 40s to combat malaria>however it was found to cause thedecline of local fish and frogs through competition of other food source as well as eating theireggs.G2@H)eeMos-uitofish in (ustralia*

?iving organisms through the process of evolution may achieve increased resistance to biological

chemical and physical methods of control over time. !n the event the target pest population is not

completely exterminated or is still capable of reproduction )were the pest control means a form of

sterili$ation* the surviving population could ac-uire a tolerance to the applied pressures " this can

result in an evolutionary arms racewith the control method. uccessful biological control reduces

thepopulation densityof the target species over several years thus providing the potential for nativespecies to re"establish. !n addition regeneration and reestablishment programs can aid the recovery

of native species. To develop or find a biological control that exerts control only on the targeted

species is a very lengthy process of researchand experiments.
http://en.wikipedia.org/wiki/Hawaiihttp://en.wikipedia.org/wiki/Hawaiihttp://en.wikipedia.org/wiki/Amphibianhttp://en.wikipedia.org/wiki/Habitathttp://en.wikipedia.org/wiki/Habitathttp://en.wikipedia.org/wiki/Toadhttp://en.wikipedia.org/wiki/Toadhttp://en.wikipedia.org/wiki/Toadhttp://en.wikipedia.org/wiki/Froghttp://en.wikipedia.org/wiki/Froghttp://en.wikipedia.org/wiki/Poisonhttp://en.wikipedia.org/wiki/Poisonhttp://en.wikipedia.org/wiki/Parotid_glandshttp://en.wikipedia.org/wiki/Parotid_glandshttp://en.wikipedia.org/wiki/Parotid_glandshttp://en.wikipedia.org/wiki/Goannahttp://en.wikipedia.org/wiki/Goannahttp://en.wikipedia.org/wiki/Tiger_snakehttp://en.wikipedia.org/wiki/Dingohttp://en.wikipedia.org/wiki/Northern_quollhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-28http://en.wikipedia.org/wiki/Organismshttp://en.wikipedia.org/wiki/Organismshttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Ecosystemshttp://en.wikipedia.org/wiki/Domino_effecthttp://en.wiktionary.org/wiki/equilibriumhttp://en.wikipedia.org/wiki/Rhinocyllus_conicushttp://en.wikipedia.org/wiki/Rhinocyllus_conicushttp://en.wikipedia.org/wiki/Thistlehttp://en.wikipedia.org/wiki/Thistlehttp://en.wikipedia.org/wiki/Thistlehttp://en.wikipedia.org/wiki/Mongoosehttp://en.wikipedia.org/wiki/Hawaiihttp://en.wikipedia.org/wiki/Rathttp://en.wikipedia.org/wiki/Endemic_birds_of_Hawaiihttp://en.wikipedia.org/wiki/Endemic_birds_of_Hawaiihttp://en.wikipedia.org/wiki/Egg_(biology)http://en.wikipedia.org/wiki/Subantarctichttp://en.wikipedia.org/wiki/Subantarctichttp://en.wikipedia.org/wiki/Prince_Edward_Islandshttp://en.wikipedia.org/wiki/Feline_distemperhttp://en.wikipedia.org/wiki/Feline_distemperhttp://en.wikipedia.org/wiki/Gambusia_holbrookihttp://en.wikipedia.org/wiki/Gambusia_holbrookihttp://en.wikipedia.org/wiki/Malariahttp://en.wikipedia.org/wiki/Malariahttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-29http://en.wikipedia.org/wiki/Mosquitofish_in_Australiahttp://en.wikipedia.org/wiki/Mosquitofish_in_Australiahttp://en.wikipedia.org/wiki/Evolutionary_arms_racehttp://en.wikipedia.org/wiki/Population_densityhttp://en.wikipedia.org/wiki/Population_densityhttp://en.wikipedia.org/wiki/Population_densityhttp://en.wikipedia.org/wiki/Researchhttp://en.wikipedia.org/wiki/Experimenthttp://en.wikipedia.org/wiki/Hawaiihttp://en.wikipedia.org/wiki/Amphibianhttp://en.wikipedia.org/wiki/Habitathttp://en.wikipedia.org/wiki/Toadhttp://en.wikipedia.org/wiki/Froghttp://en.wikipedia.org/wiki/Poisonhttp://en.wikipedia.org/wiki/Parotid_glandshttp://en.wikipedia.org/wiki/Goannahttp://en.wikipedia.org/wiki/Tiger_snakehttp://en.wikipedia.org/wiki/Dingohttp://en.wikipedia.org/wiki/Northern_quollhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-28http://en.wikipedia.org/wiki/Organismshttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Ecosystemshttp://en.wikipedia.org/wiki/Domino_effecthttp://en.wiktionary.org/wiki/equilibriumhttp://en.wikipedia.org/wiki/Rhinocyllus_conicushttp://en.wikipedia.org/wiki/Thistlehttp://en.wikipedia.org/wiki/Mongoosehttp://en.wikipedia.org/wiki/Hawaiihttp://en.wikipedia.org/wiki/Rathttp://en.wikipedia.org/wiki/Endemic_birds_of_Hawaiihttp://en.wikipedia.org/wiki/Egg_(biology)http://en.wikipedia.org/wiki/Subantarctichttp://en.wikipedia.org/wiki/Prince_Edward_Islandshttp://en.wikipedia.org/wiki/Feline_distemperhttp://en.wikipedia.org/wiki/Gambusia_holbrookihttp://en.wikipedia.org/wiki/Malariahttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-29http://en.wikipedia.org/wiki/Mosquitofish_in_Australiahttp://en.wikipedia.org/wiki/Evolutionary_arms_racehttp://en.wikipedia.org/wiki/Population_densityhttp://en.wikipedia.org/wiki/Researchhttp://en.wikipedia.org/wiki/Experiment


24/27

&ffects on invasive speciesGeditH

The invasive speciesAlternanthera philo2eroides)alligator weed* was controlled in,lorida)U..* by the

introduction ofAgasicles hygrophila)alligator weed flea beetle*

%iological control programs aim to reduce or eliminate populations of ecologically and agriculturally

harmful invasive species. xamples where this has been achieved include:

The alligator weedG0Hwas introduced to the United tates from outh (merica.This a-uatic

weed spreads rapidly and causes many problems in la#es and rivers. The weed ta#es root inshallow water causing maor problems fornavigationirrigationandflood control. Thealligatorweed flea beetleand two other biological controls were released in,lorida. %ecause of theirsuccess ,lorida banned the use of herbicides to control alligator weed three years after thecontrols were introduced.G/H

Galerucella calmariensisa leaf beetle has been introduced in 3orth (merica as a control

agent for purple loosestrife )Lythrum salicaria*.

!n the late /@th century cottony cushion scalewas discovered in the

+alifornian citrusindustry and it was feared that severe economic losses would result. oweverthe vedalia beetleand subse-uently Cryptochaetum iceryae a parasitoid fly were introduced to

control the pest. 9ithin a few years the cottony cushion scale was controlled and the citrusindustry suffered little financial loss.Gcitation neededH

(alvinia molestais a maor a-uatic weed. !t covers many waterways causing damage to

water flow and the ecosystem. This weed was incorrectly identified at first. cientists foundweevils eating this weed. They named this species of weevils C. salviniae. The weevils havebecome a great biological control success for all countries.G2H

6ric#ly pear cacti 5puntia spp. were introduced into Pueensland (ustralia as an

ornamental plant. !t -uic#ly spread to cover over 21 million hectares of (ustralia. Two controlagents were used to help control the spread of the plant. These were C. cactorum a?epidopteran species and 7actylopius spp. a emipteran species. GH

Grower educationGeditH

( potential obstacle to the adoption of biological pest control measures is growers stic#ing to the

familiar use of pesticides particularly since it has been claimed that many of the pests that are

controlled today using pesticides actually became pests because pesticide use reduced or

eliminated natural predators.G4H( method of increasing grower adoption of biocontrol involves letting
http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=17http://en.wikipedia.org/wiki/Alternanthera_philoxeroideshttp://en.wikipedia.org/wiki/Alternanthera_philoxeroideshttp://en.wikipedia.org/wiki/Alternanthera_philoxeroideshttp://en.wikipedia.org/wiki/Floridahttp://en.wikipedia.org/wiki/Floridahttp://en.wikipedia.org/wiki/Agasicles_hygrophilahttp://en.wikipedia.org/wiki/Agasicles_hygrophilahttp://en.wikipedia.org/wiki/Alligator_weedhttp://en.wikipedia.org/wiki/Alligator_weedhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-30http://en.wikipedia.org/wiki/South_Americahttp://en.wikipedia.org/wiki/South_Americahttp://en.wikipedia.org/wiki/Navigationhttp://en.wikipedia.org/wiki/Navigationhttp://en.wikipedia.org/wiki/Navigationhttp://en.wikipedia.org/wiki/Irrigationhttp://en.wikipedia.org/wiki/Irrigationhttp://en.wikipedia.org/wiki/Flood_controlhttp://en.wikipedia.org/wiki/Flood_controlhttp://en.wikipedia.org/wiki/Agasicles_hygrophilahttp://en.wikipedia.org/wiki/Agasicles_hygrophilahttp://en.wikipedia.org/wiki/Agasicles_hygrophilahttp://en.wikipedia.org/wiki/Floridahttp://en.wikipedia.org/wiki/Floridahttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-31http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-31http://en.wikipedia.org/wiki/Galerucella_calmariensishttp://en.wikipedia.org/wiki/Galerucella_calmariensishttp://en.wikipedia.org/wiki/Lythrum_salicariahttp://en.wikipedia.org/wiki/Icerya_purchasihttp://en.wikipedia.org/wiki/Icerya_purchasihttp://en.wikipedia.org/wiki/Citrushttp://en.wikipedia.org/wiki/Citrushttp://en.wikipedia.org/wiki/Vedalia_beetlehttp://en.wikipedia.org/w/index.php?title=Cryptochaetum_iceryae&action=edit&redlink=1http://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-32http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-33http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=18http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=18http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-34http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=17http://en.wikipedia.org/wiki/Alternanthera_philoxeroideshttp://en.wikipedia.org/wiki/Floridahttp://en.wikipedia.org/wiki/Agasicles_hygrophilahttp://en.wikipedia.org/wiki/Alligator_weedhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-30http://en.wikipedia.org/wiki/South_Americahttp://en.wikipedia.org/wiki/Navigationhttp://en.wikipedia.org/wiki/Irrigationhttp://en.wikipedia.org/wiki/Flood_controlhttp://en.wikipedia.org/wiki/Agasicles_hygrophilahttp://en.wikipedia.org/wiki/Agasicles_hygrophilahttp://en.wikipedia.org/wiki/Floridahttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-31http://en.wikipedia.org/wiki/Galerucella_calmariensishttp://en.wikipedia.org/wiki/Lythrum_salicariahttp://en.wikipedia.org/wiki/Icerya_purchasihttp://en.wikipedia.org/wiki/Citrushttp://en.wikipedia.org/wiki/Vedalia_beetlehttp://en.wikipedia.org/w/index.php?title=Cryptochaetum_iceryae&action=edit&redlink=1http://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Biological_pest_control#cite_note-32http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-33http://en.wikipedia.org/w/index.php?title=Biological_pest_control&action=edit&section=18http://en.wikipedia.org/wiki/Biological_pest_control#cite_note-34


25/27

growers learn by doing for example showing them simple field experiments having observations of

live predation of pests or collections of parasitised pests. !n the 6hilippines early season sprays

against leaf folder caterpillars were common practice but growers were as#ed to follow a &rule of

thumb& of not spraying against leaf folders for the first 0 days after transplanting> participation in this

resulted in a reduction of insecticide use by /J and a change in grower perception of insecticide

u

biological management

Documents