use of biopesticides
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Use of Biopesticides for the Control of Insect Pests
Use of Biopesticides for the Control of Insect Pests
Dr. R.C.SihagDr. R.C.SihagProfessorProfessor
Department of Zoology & Department of Zoology & Aquaculture,Aquaculture,
CCS Haryana Agricultural University,CCS Haryana Agricultural University,Hisar-125004, IndiaHisar-125004, India
Table:1 History of Table:1 History of Development of PesticidesDevelopment of Pesticides
YEAR CHEMICAL LOCATION
900 ARSENICALS CHINA
1090 TOBACCO & SOAPS EUROPE
1800 PYRETHRINS CAUCASUS
1867 PARIS GREEN U.S.A.
1883 BOURDEAUX MIXTURE FRANCE
MODERN ERA
1939-40 DDT-TOXIC PROPERTIES DISCOVERED SWITZERLAND
1941-42 BHC- TOXIC PROPERTIES DISCOVERED FRANCE, U. K.
1942-60 CYCLODIENES, CARBAMATES AND EUROPE, U. S. A.
OP COMPOUNDS
1962 RACHEL CARSON'S BOOK SILENT U. S. A.
SPRING APPEARS
1970- 71 TRIALS AGAINST DDT BEGINS SWEEDEN
1975-80 SYNTHETIC PYRETHROIDS JAPAN
1980-81 CHITIN INHIBITORS U. S. A.
1981 BIO-PESTICIDES AND TRANSGENIC U. S. A..
ONWARDS PLANTS
BiopesticidesBiopesticides► Constitute the pest control agents of Constitute the pest control agents of
biological origin biological origin ► Microbials: bacteria, fungi, viruses, protozoaMicrobials: bacteria, fungi, viruses, protozoa► Pheromones/semiochemicals: message-Pheromones/semiochemicals: message-
bearing substances produced by plants and bearing substances produced by plants and animals (interfere with mating or disrupt animals (interfere with mating or disrupt pest insect behaviour)pest insect behaviour)
► Invertebrate Biological Control Agents Invertebrate Biological Control Agents (macro organisms): parasitoids, predators (macro organisms): parasitoids, predators and parasitesand parasites
► Botanical pesticidesBotanical pesticides► Transgenic cropsTransgenic crops
Table:2 Table:2 Agrochemicals Vs. Agrochemicals Vs. BiologicalsBiologicals
Factors Agrochemicals Agri-biologicals
Cost effectiveness Cheap but increased spraying cost
Costlier but reduced number of applications
Persistence and residual effect
High Low, mostly Bio-degradable and self perpetuating
Knockdown effect Immediate Delayed
Handling and Bulkiness Easy but danger and Hazardous
Bulky : Carrier basedEasy : Liquid formulation
Pest resurgence More Less
Resistance More prone Less prone
Effect on Beneficial flora At times destruction of friendly pest
Less harmful on beneficial pests
Target specificity Mostly broad spectrum Mostly host specific
Waiting time Very high Almost nil
Nature of control Curative Preventive
Shelf life More Less
(Source : agriculture Today. Nov. 2005)
Microbial Microbial insecticidesinsecticides
► Consist of a microorganism as the active Consist of a microorganism as the active ingredient (e.g., bacterium, fungus, virus or ingredient (e.g., bacterium, fungus, virus or protozoan)protozoan)
► About 3000 reported to cause diseases in About 3000 reported to cause diseases in insectsinsects
► Viruses isolated from 1000 species of insectsViruses isolated from 1000 species of insects► More than 100 bacteria identified as pathogensMore than 100 bacteria identified as pathogens► Over 800 fungal species belonging to 100 Over 800 fungal species belonging to 100
genera recognizedgenera recognized► More than 100 protozoans identified as More than 100 protozoans identified as
pathogenspathogens
VirusVirus►Set of one or more nucleic acid Set of one or more nucleic acid
template molecules, normally encased template molecules, normally encased in a protective coat or coats of protein in a protective coat or coats of protein or lipoprotein that is able to organize or lipoprotein that is able to organize its own replication only within suitable its own replication only within suitable host cellshost cells
Table:3 Table:3 Characteristics of Viruses Characteristics of Viruses found in insectsfound in insects
Virus Virus Nucleic acidNucleic acid Virus Virus particleparticle
Inclusion body Inclusion body shapeshape
Subgroups and Subgroups and common namescommon names
Ascoviridae Ds DNA Allantoid None -
Baculoviridae Ds DNA Bacilliform Polyhedral NPV
Cigar- shaped capsules
GV
Calciviridae ss RNA Isometric None -
Iridoviridae ss DNA Isometric None Iridscent
Nodaviridae ss RNA Isometric None -
Parvoviridae ss DNA Isometric None -
Picornaviridae ss RNA Isometric None -
Polydnaviridae ssDNA Ovoid None -
Poxviridae Ds DNA Ovoid or brick shaped
Spheroid Entomopox viruses
Reoviridae Ds DNA Isometric Polyhedral Cytoplasmic polyhedrosis
Rabhdoviridae ss RNA Helical None -
BaculovirusesBaculoviruses► Rod-shaped, double stranded DNA genomes of 88-Rod-shaped, double stranded DNA genomes of 88-
153 kbp 153 kbp ► Causes infection by mouthCauses infection by mouth► Replicate rapidly & causes extensive cell and tissue Replicate rapidly & causes extensive cell and tissue
destruction in host celldestruction in host cell► Mostly found in nucleus of host cellsMostly found in nucleus of host cells► Virions are contained within proteinaceous particles Virions are contained within proteinaceous particles
called occlusion bodiescalled occlusion bodies► Can be mass produced by single cottage industriesCan be mass produced by single cottage industries► Highly host specific and have been isolated only from Highly host specific and have been isolated only from
invertebratesinvertebrates► Primarily pathogens of insects of order Lepidoptera Primarily pathogens of insects of order Lepidoptera
but can also infect Hymenoptera, Diptera, Coleoptera but can also infect Hymenoptera, Diptera, Coleoptera and Trichopteraand Trichoptera
► Apprx. 60 percent of Apprx. 60 percent of 1200 known insect 1200 known insect viruses belongs to viruses belongs to family baculoviridaefamily baculoviridae
► Baculovirus infection Baculovirus infection described in 700 described in 700 species of species of invertebratesinvertebrates
OrderOrder SpeciesSpecies
LepidopteraLepidoptera 455455
HymenopteraHymenoptera 3131
DipteraDiptera 2727
ColeopteraColeoptera 55
NeuropteraNeuroptera 22
TrichopteraTrichoptera 11
ThysanopteraThysanoptera 11
SphanopteraSphanoptera 11
Baculovirus
NPVMany virions within occlusion body called polyhedra, occurs in nucleus
GVOne or two virions within occlusion
body called granules, occurs in nuclear- cytoplasmic milieu after
rupture of nuclear membrane
SNPV Single packaging
of nucleocapsid in virion
MNPVmultiple packaging
of nucleocapsid in virion
Mode of Action
Table:4 Efficacy of Table:4 Efficacy of Baculoviruses against Baculoviruses against
insect pestsinsect pestsVirus Dose Pest Mortality (%)
Reference
HzNPV 100-250 LE/ha
Helicoverpa zea
90- 96 Dhaliwal et al., 2007
SINPV 375 LE/ha Spodoptera litura
95.00 Arora et al., 2003
HaNPV 1 X 108 OB’s Helicoverpa armigera
90.60 Snegapriya and Manjula, 2008
AgNPV 50 LE/ha Anticarsia gemmatalis
80.00 Dhaliwal et al., 2007
SNPV - Helicoverpa armigera
Effective control
Hu et al., 2003
SfNPV 2.5X 1011 OB’s
Spodoptera frugiperda
Effective control
Dhaliwal et al., 2007
Genetic Genetic ImprovementImprovement
►To combine pathogenecity of virus with To combine pathogenecity of virus with insecticidal action of a toxin, hormone insecticidal action of a toxin, hormone or enzymeor enzyme
►To improve production, modifying host To improve production, modifying host range & enhancing utility range & enhancing utility
►To reduce the time from infection with To reduce the time from infection with recombinant virus to death of infect recombinant virus to death of infect such that feeding damage is below such that feeding damage is below economic threshold economic threshold
Recombinant DNA Technology
Viral Genomic DNA Plasmid
Cultured insect cells
b
A B
a
Foreign gene
b
a b
Viral DNA
Transfer vector
Homologous recombination
Allelic replacement
Screening by Plaque assay selection of recombinant virus
ExamplesExamples► Buthus eupeus Buthus eupeus insect toxin- 1 (BeIt) is an insect insect toxin- 1 (BeIt) is an insect
specific paralytic neurotoxin isolated from scorpion specific paralytic neurotoxin isolated from scorpion Buthus eupeus, Buthus eupeus, was inserted into AcMNPV was inserted into AcMNPV ((Autographa californica Autographa californica multiple nuclear multiple nuclear polyhedrosis virus) genome under control of polyhedrosis virus) genome under control of polyhedrin gene promoterpolyhedrin gene promoter
► Juvenile hormone esterase (JHE) gene from tobacco Juvenile hormone esterase (JHE) gene from tobacco hornworm, hornworm, Heliothis virescensHeliothis virescens genome into AcMNPV genome into AcMNPV genome. In late instar lepidopterous larvae, genome. In late instar lepidopterous larvae, juvenile hormone is inactivated by an increase in juvenile hormone is inactivated by an increase in JHE level, this reduction in JH titers initiates JHE level, this reduction in JH titers initiates metamorphosis to the pupal stage and to a metamorphosis to the pupal stage and to a cessation of feedingcessation of feeding
Kaushik, 2008
Field Stability and Field Stability and PersistencePersistence
► Highly susceptible to damage by desiccation Highly susceptible to damage by desiccation and by exposure to sunlight or UV radiationsand by exposure to sunlight or UV radiations
► Additives like Charcoal, egg albumin, Additives like Charcoal, egg albumin, molasses, optical brighteners and sugarmolasses, optical brighteners and sugar
► Addition of crude sugar (15%) to HaNPV Addition of crude sugar (15%) to HaNPV spray fluid increased persistence of virus spray fluid increased persistence of virus both under natural sunlight and shadeboth under natural sunlight and shade
► Brighteners reduces the LCBrighteners reduces the LC5050 of gypsy moth of gypsy moth Lymantia disparLymantia dispar NPV by 800- 1300 fold NPV by 800- 1300 fold
► Evening sprayEvening spray
Baculoviruses are Baculoviruses are safesafe
►Only found in insects (mainly Only found in insects (mainly lepidopterean species)lepidopterean species)
►Narrow host range, high selectivityNarrow host range, high selectivity►No production of metabolites or toxinsNo production of metabolites or toxins►Baculoviruses are safe and cause no Baculoviruses are safe and cause no
hazards to human healthhazards to human health
ProtozoansProtozoans► More than 1000 species pathogenic to More than 1000 species pathogenic to
insectsinsects► Chronic nature of infection so limited Chronic nature of infection so limited
efficiencyefficiency► Few are Highly virulent or fast acting so Few are Highly virulent or fast acting so
more appropriate for long term control more appropriate for long term control programmes with high economic injury programmes with high economic injury levellevel
► Sarcomastigophora, Apicomplexa, Sarcomastigophora, Apicomplexa, Microspora and CiliophoraMicrospora and Ciliophora
Table:Table:5 Protozoans 5 Protozoans considered for control of considered for control of
insect pestsinsect pestsParasiteParasite HostHost
MicrosporidiansMicrosporidians
Nosema acridophagous, N. Nosema acridophagous, N. cuneatum, N. locustaecuneatum, N. locustae
GrasshoppersGrasshoppers
N. algeraeN. algerae Anopheles albimanus, Culex Anopheles albimanus, Culex tritaeniorhynchustritaeniorhynchus
N. fumifueranaeN. fumifueranae Spruce budwormSpruce budworm
N. heliothidisN. heliothidis Helicoverpa zeaHelicoverpa zea
N. pyraustaN. pyrausta Ostrinia nubialisOstrinia nubialis
N. whiteiN. whitei Tribolium castaneumTribolium castaneum
N. N. spp.spp. Helicoverpa armigera, Spodoptera Helicoverpa armigera, Spodoptera litura litura
Vairimorpha necatrixVairimorpha necatrix Agrotis ipsilon, Helicoverpa zeaAgrotis ipsilon, Helicoverpa zea
Contd….Contd….ParasiteParasite HostHost
Septate gregarines
Gregarina garnhani Schistocera gregaria
G. polymorpha Tenebrio molitor
Aseptate gregarines
Ascogregarina culicis, A. geniculati
Aedes aegypti
Neogregarines
Mattesia trogodermae Trogoderma granarium
Farinocystis tribolii Tribolium castaneum
Mode of ActionMode of Action► Similar to that of virusesSimilar to that of viruses► N. N. spp. normally invade fat body and spp. normally invade fat body and
pericardiumpericardium► Pathogenecity expression:Pathogenecity expression: Increased Increased
mortality rates, reduced fecundity, delayed mortality rates, reduced fecundity, delayed development, decreased activity and reduced development, decreased activity and reduced food consumptionfood consumption
► Cytopathological effects:Cytopathological effects: Nuclear and cellular Nuclear and cellular hypertrophy, extensive alteration of hypertrophy, extensive alteration of cytoplasmic organelles like ER, Mitochondria, cytoplasmic organelles like ER, Mitochondria, ribosome bodies, protein granules and ribosome bodies, protein granules and vacuolesvacuoles
Metarhizium anisopliae Beauveria bassiana infection of Clover Worm
Beauveria bassiana infection of worm within woody substrate
Fungi
Table:6 Entomopathogens used Table:6 Entomopathogens used for the control of pestsfor the control of pests
ProductProduct FungusFungus TargetTarget
Mycotol, Vertalec Verticillium lecanii Whitefly, thrips and aphids
Meta guard, Metarhizium anisopliae Termites
Biogreen Metarhizium anisopliae Locusts
Bio-Path Metarhizium anisopliae Cockroaches
Bio-Blast Metarhizium anisopliae Termites
Cobicant Metarhizium anisopliae Sugarcane spittle bug
Bio-Cane Metarhizium anisopliae Cane grubs
Green Muscle Metarhizium anisopliae Locusts, grasshoppers
Conidia Beauveria bassiana Coffee berry borer
Cornguard Beauveria bassiana European corn borer
Naturalis- L Beauveria bassiana Cotton pests
Mycotrol GH Beauveria bassiana Locusts, grasshoppers
Mycotrol WH and Botanigard
Beauveria bassiana Whitefly, aphids, thrips
PFR- 97, Pae- Sin Paecilomyces fumosoroseus
Whitefly
Entomopathogenic fungi -in Insect Control
Entomopathogenic fungi -in Insect Control
Tea Mites
Rice bugs
Helicoverpa Beauveria infected Helicoverpa
Paecilomyces infected tea mites
Metarhizium infected rice bugs
The Pests which are difficult to control by Pesticides can be controlled by Biopesticides
Mode of action of Mode of action of Entomopathogenic fungiEntomopathogenic fungi
Table: 7 Table: 7 Selected Selected metabolites of importantmetabolites of important Entomopathogenic fungiEntomopathogenic fungi
Pathogen Metabolite
Metarhizium anisopliae Destruxins (>27 types), cytochalasin
Beauveria bassiana Bassianin, beauvericin, bassianolide, tenellin
Beauveria brogniartii Oosporein
Paecilomyces fumosoroseus Beauvericin, beauverolies, pyridine-2,6-dicarboxylic acid
Verticillium lecanii Dipcolonic acid, hydroxycarboxylic acid,
vertilecannins, bassianolide
Tolypocladium spp. Cyclosporin, efrapeptins (5 types)
Hirustella thompsonii Hirsutellin A, hirsutellin B, phomalatone
► Destruxins :Destruxins : cyclic peptides, biological activity cyclic peptides, biological activity includes disruption of calcium balance in cells and includes disruption of calcium balance in cells and inhibition of vacuolar ATPasesinhibition of vacuolar ATPases
► Beauvericin:Beauvericin: hexadepsipeptide produced by hexadepsipeptide produced by Beauveria bassiana, Paecilomyces fumosoroseus Beauveria bassiana, Paecilomyces fumosoroseus and Fusariumand Fusarium spp. It shows antibiotic activity spp. It shows antibiotic activity against several species of bacteria and moderate against several species of bacteria and moderate insecticidal activityinsecticidal activity
► Bassianolide:Bassianolide: Lethal at high doses but induce Lethal at high doses but induce atonical symptoms at low doses in silkwormatonical symptoms at low doses in silkworm
► Bassianin and Tenellin:Bassianin and Tenellin: non-peptide toxins non-peptide toxins inhibits erythrocyte membrane ATPasesinhibits erythrocyte membrane ATPases
► Hirsutellin:Hirsutellin: Antigenic, thermostable protein. Antigenic, thermostable protein. Hirsutellin A Hirsutellin A is highly toxic to larvae of wax is highly toxic to larvae of wax moth and mosquitoesmoth and mosquitoes
► Efrapeptins:Efrapeptins: produced byproduced by Tolypocladium Tolypocladium spp.,spp., iinsecticidal and miticidal activity, limited nsecticidal and miticidal activity, limited antimicrobial activityantimicrobial activity
Factors influencing Factors influencing fungal efficacyfungal efficacy
►The PathogenThe Pathogen►The Insect hostThe Insect host►The EnvironmentThe Environment
The PathogenThe Pathogen► Virulent strain must be compatible with the Virulent strain must be compatible with the
hosthost► Spore density must be highSpore density must be high► Virulent strain must have low LDVirulent strain must have low LD50 50 & LT& LT5050
► Ecologically fit strains Ecologically fit strains persists well in fieldpersists well in fieldmore tolerant to UV radiationmore tolerant to UV radiationresist desiccation, microbial attackresist desiccation, microbial attackhave sufficient endogenous reserves to have sufficient endogenous reserves to survive adverse conditions survive adverse conditions
Insect hostInsect host► Stress Stress
Starved Starved Plutella xylostella Plutella xylostella larvae more larvae more susceptible than fed larvae tosusceptible than fed larvae to Paecilomyces Paecilomyces fumosoroseus fumosoroseus (Altre and Vandenberg, 2001)(Altre and Vandenberg, 2001)
► Developmental stage Developmental stage ► Insect densityInsect density► Insect behaviour (foraging & grooming)Insect behaviour (foraging & grooming)
Conidia of Conidia of M. anisopliae M. anisopliae are spread among are spread among individual termites by groomingindividual termites by groomingForaging coccinellids transfer conidia from Foraging coccinellids transfer conidia from sporulating cadavers to healthy aphids sporulating cadavers to healthy aphids inducing significant mortalities in aphid inducing significant mortalities in aphid populationpopulation
EnvironmentEnvironment►Solar radiations Solar radiations ►TemperatureTemperature►Relative humidityRelative humidity►RainfallRainfall►Host plantHost plant
Table:8 Efficacy of Fungi Table:8 Efficacy of Fungi against pestsagainst pests FungusFungus ConcentrationConcentration
(conidia/ ml)(conidia/ ml)Pests (Crop)Pests (Crop) Mortality Mortality
(%)(%)ReferenceReference
Beauveria bassiana 1 X 108 Lygus lineeolaris 77.47 Sabbahi et al., 2008
1 X 108 Anthonomus signatus 60.35
1 X 108 Otiorhynchus ovatus 54.50
1 X 1010 Holotrichia consanguinea
56.67 Jat and Choudhary, 2006
5 X 109 Holotrichia consanguinea
53.33
1 X 107 Varroa destructor 100.00 Meikle et al., 2006
Metarhizium anisopliae
1 X 107 Varroa destructor 75.00 Meikle et al., 2006
Beauveria bassiana 4 X 1012 to 5 X 1012
Nilaparvata lugens 63- 98 Dhaliwal et al., 2007
2 X 1012 Helicoverpa armigera 100.00 Gulati et al., 2008
2X 1012 Spodoptera litura 100.00 Gulati et al., 2008
1X 109 Pieris brassicae 50.00 Gulati et al., 2008
Nomurea rileyi 1 X 108 Helicoverpa armigera 82.10 Snegapriya and Manjula, 2008
1 X 109 Helicoverpa armigera 70.00 Manjula and krishnamurthy, 2005
1 X 109 Spodoptera litura 53.40 Manjula and krishnamurthy, 2005
Crystal
Sporulated culture
Bacillus thuringiensisBacillus thuringiensis (Bt) (Bt)
Bacteria
Insecticidal toxin of Bacillus thuringiensis B. thuringiensis is an aerobic spore-forming
bacterium which produces a toxin (Bt toxin or Cry) that kills certain insects
The Bt toxin or Cry is produced when the bacteria sporulates and is present in the parasporal crystal
Several different strains and subspecies of B. thuringiensis exist and produce different toxins that kill specific insects
They have no toxicity to human & there is no withholding period on produce sprayed with Bt
Table:9 Some properties of the insecticidal toxins from various strains of B. thuringiensisStrain/subsp. Protein size Target
InsectsCry #
berliner 130-140 kDa Lepidoptera CryI (Cry1Aa)
kurstaki KTP, HD1
130-140 kDa Lepidoptera CryI (Cry1Ab)
entomocidus 6.01
130-140 kDa Lepidoptera CryI (Cry1Ba)
aizawai 7.29 130-140 kDa Lepidoptera CryI (Cry1Ca)
aizawai IC 1 135 kDa Lepidoptera, Diptera
CryII (Cry1Da)
kurstaki HD-1 71 kDa Lepidoptera, Diptera
CryII (Cry2Ab)
tenebrionis (sd) 66-73 kDa Coleoptera CryIII (Cry3Aa)
morrisoni PG14 125-145 kDa Diptera CryIV (Cry4Aa)
israelensis 68 kDa Diptera CryIV (Cry4Ba)
Cry protein: mode of action The Cry protein is made as an inactive protoxin Conversion of the protoxin (e.g., 130 kDa) into the
active toxin (e.g., 68 kDa) requires the combination of a slightly alkaline pH (7.5-8) and the action of a specific protease(s) found in the insect gut
The active toxin binds to protein receptors on the insect gut epithelial cell membrane
The toxin forms an ion channel between the cell cytoplasm and the external environment, leading to loss of cellular ATP and insect death
Bt strain Trade name Uses
Bt var. aizurai Florback, Centari Diamondback moth
Bt var. galleriae Certan Wax moth larvae in honey combs
Bt var. israelensis Bactimos, Bactis, Thurimos, Vectobac
Larvae of mosqitoes and balckflies
Bt var. kurstaki Bt, Biobit, Dipel, Delfin, Javelin
Lepidopterous larvae
Bt var. sandiego Diterra, M- one plus
Beetles and weevils
Bt var. thuringenesis Muscabac, Thuricide
Flies, Lepidopterous larvae
Table:10Table:10 Bt based commercially available pesticides
Mechanism of Resistance Lower level of toxin activation
Bt resistant strain of Plodia interpunctella displayed slower processing and activation of Cry 1 protoxinsHeliothis virescens exhibited slow activation as well as faster degradation of toxin by midgut extracts
Reduced binding to midgut membraneP. interpunctella was found to highly resistant to Cry 1Aa, Cry 1Ab and Cry 1Ac but not to Cry 1B, Cry 1C and Cry 1D.
How to prevent it? Production of hybrid Bt toxins Stacking of Bt toxin genes Use of Bt toxins in combination with other
insecticidal proteins such as chitinase and Cyt1A
In plants, the planting of crop buffer zones with non-genetically engineered Bt plants to maintain an insect susceptible population
Bt and Human Health Risks The toxicology pathway
– Hazard is ubiquitous – Exposure (contact) is not unusual – Doses are low (below threshold for response) Results of mammalian, human studies – No effects at doses > 5,000 mg/kg Cry proteins Contrast with other insecticides – Response follows the dose
Registered MicrobialActive Ingredients Agrobacterium radiobacter Bacillus thuringiensis subsp. kurstaki Bacillus thuringiensis subsp. Israelensis Bacillus thuringiensis subsp. tenebrionis Colletotrichum gloeosporioides f.sp. malvae Cydia pomonella Granulovirus Chondrostereum purpureum Strain HQ1
Gypsy Moth Nucleopolyhedrovirus (NPV) Red-Headed Sawfly NPV HaNPV Pseudozyma flocculosa Streptomyces griseoviridis Strain K61 Ophiostoma piliferum(pending) Beauveria bassiana Metarhizium anisoplia Verticillium lecanii Nomurea rileyi
Safety testing of microbials
Necessary to know what are the hazards infection of man, livestock, useful animals and plantsPoisoning, allergy, carcinogenesis by toxins
Routes of hazards oral (by food)RespirationParenterel in woundsDermal (through skin)Might occur during production, packaging and storage of pathogens, application to crops, operations during post- harvest crop storage, consumption of treated crop & by environmental pollution
3- tier testingTier I : Includes acute oral, inhalation, intraperitoneal, dermal and ocular application plus allergenicity tests and mutagenecity screensTier II: Quantification of the effects and expanded mutagenecity testsTier III: Tetratogenecity and long term tests
Microbials are non-toxic to man and vertebrates because digestion of proteins is at low ph. Stomach enzyme pepsin (ph=2) degrades the endotoxin into atoxic compound
Table:11 Summary of desirable characteristics required by microbial pesticidesCharacteristic Bacteria Fungi Viruses Protozoa
Time to kill Good Poor Poor Poor
Easy to apply Yes Yes Yes Yes
Storage Characteristics
Good Poor Good Poor
Environmental stability
Poor Poor Poor Poor
Safe to non target organisms
Yes Yes Yes Yes
Easy to produce Yes Yes Poor Poor
BotanicalsBotanicals
Allium cepa
Chrysanthemum sp. Annona squamosa Tagetes erecta
Ricinus communis Ipomoea fistulosa
► Pesticides derived from plants Pesticides derived from plants ► Generally act in one of two ways: Generally act in one of two ways:
contact poisoncontact poison
stomach poisonstomach poison► About 2,50,000 plant species evaluatedAbout 2,50,000 plant species evaluated► 2121 useful in pest management2121 useful in pest management
1005 exhibited insecticidal activity1005 exhibited insecticidal activity
384 antifeedants384 antifeedants
297 repellents297 repellents
27 attractants27 attractants
31 growth inhibiting properties31 growth inhibiting properties
Purohit and Vyas, 2004
Table:12Table:12 Characteristics of major Characteristics of major traditional botanicalstraditional botanicals
Botanical insecticide
Source plant (s) Mode of action Toxicity Uses
Pyrethrins Flowers of pyrethrum daisy, Tanacetum
(Chrysanthemum) cinerariaefolium
Interferes with Na & k ion movement in
nerve axons
Mammalian oral
LD50 >1000, some allergic reactions can
occur
On pests and humans to control fleas, ticks ,
lice Breaks down rapidly
Rotenone Roots of Derris, Lonchocarpus, other
tropical legumes
Disrupts energy metabolism in mitochondria
Oral LD50 =25-3000
Dermal>1000
In gardens& orchards against many insects
especially beetles. Persists effectively for 4-5 days or more. Use
as a fish poison
Sabadilla Seeds of tropical lily Schoenocaulon officinale and european Veratrum
album
Interferes with Na & k ion movement in
nerve axons. Irritates skin and
mucous membranes, potent inducer of sneezing
Oral LD50 near 4000
In vegetables and fruits against bugs and citrus
thrips. Breaks down rapidly
Ryania Wood stems of Ryania speciosa
Activate Ca++ ion release channels
and causes paralysis in
muscles of insects and vertebrates
Oral LD50 near 1000 Dermal
near 4000
In fields &fruit crops against caterpilllars
&thrips. Often combine with rotenone &
pyrethrins in commercial mixtures
for garden use
Nicotine Tobacco, Nicotiana sp., Duboisia, Anabasis, Asclepis, Equistem,
Lycopodium
Mimics acetylcholine & overstimulates
receptor cells to cause
convulsions & paralysis
Oral LD50= 3-
188 Dermal near 50
Very toxic to
humans
Mostly in greenhouses &
gardens. Nicotine
fumigations target aphids, thrips &mites
Neem Leaves, bark, seeds of neem (Azadirachta indica)
& chinaberry (Melia azedarach )
Biochemical nature of feeding
deterrence, repellance,
growth regulation
effects are not well described
Oral LD50 > 13000
Use medicinally in humans. On
many crops & landscape
plants especially
against soft bodied&
secondary pests. Very
short persistence on treated plants
Limonene/
Linalool
Citrus oils Causes spontaneous stimulation of
sensory nerves, biochemical
mode of action
Limonene oral LD50
>5000Dermal>3500
Mostly in pet shampoos, dip & sprays to kill fleas & ticks.
Very short persistence on treated plants
Source: Weinzierl (2000)
Mode of action of BotanicalsMode of action of Botanicals Ovipositional deterrentOvipositional deterrent► affects the egg laying and egg hatchingaffects the egg laying and egg hatching► may be due to strong odour of product or presence of may be due to strong odour of product or presence of
substance which causes malfunctioning of ovariole in substance which causes malfunctioning of ovariole in females. eg. females. eg. Pongamia pinnataPongamia pinnata, , Annona squamosaAnnona squamosa
OvicidalOvicidal► kill eggs and disrupts embryonic development so kill eggs and disrupts embryonic development so
prevents hatching of eggs. Eg. prevents hatching of eggs. Eg. Annona squamosa, Annona squamosa, Parthenium Parthenium sp.sp.
Attractants eg. Attractants eg. RepellentsRepellents eg. Fennel ( eg. Fennel (Foeniculum vulgareFoeniculum vulgare), ),
Eucalyptus globulus, Moringa oleifera, Allium cepa, Eucalyptus globulus, Moringa oleifera, Allium cepa, MenthaMentha
Feeding deterrents/ AntifeedantsFeeding deterrents/ Antifeedants► Gustatory substances which causes the pest to stop Gustatory substances which causes the pest to stop
feeding and starve to death or causes cessation of feeding and starve to death or causes cessation of feeding. Eg. feeding. Eg. Melia azedarach, Melia azedarach, Neem, Garlic, Datura Neem, Garlic, Datura
Contd….Contd…. Antigonadal agentsAntigonadal agents ► Vapours of oil of Vapours of oil of Acorus calamusAcorus calamus reported to inhibit reported to inhibit
the development of ovaries of a no. of stored grain the development of ovaries of a no. of stored grain pests pests
► In male insects it showed sperm malformation and In male insects it showed sperm malformation and agglutinationagglutination
Insect growth regulators Insect growth regulators eg. eg. Lantana Lantana sp., sp., Pongamia Pongamia pinnatapinnata
Physiological effectsPhysiological effects► slow necrosis of mid gut epithelial cellsslow necrosis of mid gut epithelial cells► reduction in size and no. of cellsreduction in size and no. of cells► Malformation of circular and longitudinal muscles or Malformation of circular and longitudinal muscles or
welling of organelles when taken as stomach poisonwelling of organelles when taken as stomach poison NeurotoxinNeurotoxin
Which type of plants Which type of plants should we use?should we use?
The plant should be a perennialThe plant should be a perennial It should have a wide distribution & be present It should have a wide distribution & be present
in large numbers in nature otherwise it should in large numbers in nature otherwise it should be possible to grow it by agricultural practices.be possible to grow it by agricultural practices.
The plant parts used should be removable: The plant parts used should be removable: leaves, flowers or fruitleaves, flowers or fruit
Harvesting should not mean destruction of the Harvesting should not mean destruction of the plantplant
Plants should require small space, reduced Plants should require small space, reduced management, little water and fertilizationmanagement, little water and fertilization
Plant should not otherwise have a high Plant should not otherwise have a high economic valueeconomic value
The active ingredient should be effective at The active ingredient should be effective at low rateslow rates
Table:13Table:13 Important plants with Important plants with pesticidal activitypesticidal activity
Common name
Scientific name Plant parts used
Active principle
Custard apple
Annona squamosa Leaves and bark Annonin, squamocin
Pongam Pongamia glabra Leaves, fruits, seeds, oil roots and flowers
Pongamol, Pongapin, pongone, karanjanin
Eucalyptus Eucalyptus globulus Leaf and oil Camphene, limonene, linalool, α- terpienol
Moringa Moringa olefifera Leaves, flowers Moringyne
Clerodenderon
Clerodenderon indicum
Leaves Trans- decalin, clerodin
Ipomoea Ipomoea fistulosa Leaves, flowers and whole plant
Ipomomin, isoergin, ergine, ipalbdinium
Murraya Murraya koenigii Leaves and bark Murraxonin, murrayanone
Jatropha Jatropha curcas Leaves, seed, seed cake, oil
Jatrophin, curcusone, jatrophol
Common name
Scientific name Plant parts used Active principle
Datura Datura strmonium Leaves, fruits, dried seeds, roots
Atropine, hyoscyamine
Tobacco Nicotiana tabacum Leaves, whole plant Nicotine, nornicotine, anabasine
Sweet flag Acorus calamus Rhizomes Calamol, α asarone, β asarone
Lantana Lantana camera Leaves, whole plant Lantonolic acid, lantic acid
Indian Aloe Aloe vera Leaves, rhizomes Aloesin, aloin
Calotopis Calotropis gigantea Leaves, roots Calatropin, calatoxin
Mint Mentha spicata Leaves, flowers, whole plant, oil
Menthole, limonene, menthone
Ocimum Ocimum sanctum, O. basilicium
Leaves, stems, whole plants, oil
Juvocimene- I, II, ocimin
Onion Allium cepa Bulb Oleic acid, cepocode- D, α and β tocopherols
Common name
Scientific name Plant parts used Active principle
Garlic Allium sativum Leaves, flowers, whole plant, bulbs
Allicin, diallyl sulphide
Chilli Capsicum annum Leaves and fruits Capsacin
Marigold Tegetes erecta Leaves, flowers, roots
Mycene, tagetone. allopatulein
Lemon grass
Cymbopogon marginatus
Leaves and roots Cymbopogon, Cymbopogonal
Turmeric Curcuma longa Rhizomes Curcumol, curcumin
Ginger Zingiber officinali Rhizomes Gingerols, arcurcumene
Khejiri Prosopis julifora Leaves and seeds Juliprosopine, prosopidione, juliflorinine
Ardusa Ailanthus excelsa Leaves Ailanthone
Castor Ricinus communis Leaves and oil Ricin, ricinnie
Source: Dodia et al. (2008)
Pest resistance to Pest resistance to phytochemicalsphytochemicals
►Neem tree itself is attacked by about Neem tree itself is attacked by about 60 species of insects besides mites, 60 species of insects besides mites, nematodes and 16 phytopathogens nematodes and 16 phytopathogens like like Aonidiella orientalis, Pulvinaria Aonidiella orientalis, Pulvinaria maxima maxima etcetc
►Some resistance to pyrethrins has Some resistance to pyrethrins has been reported among a few been reported among a few agricultural pests, particularly those agricultural pests, particularly those with resistance to organochlorines, with resistance to organochlorines, orgaophosphates and carbamatesorgaophosphates and carbamates
Table:14 Efficacy of botanicals Table:14 Efficacy of botanicals against non insect pestsagainst non insect pests
Plant material Activity of material
Against Disease/ organism
Reference
Leaf extract of Datura
Inhibits mycelial growth
Aspergilllus flavus Satish et al., 2002
Inhibits mycelial growth
Die back of chilli Gehlot, 2005
Fungicidal activity
Paddy diseases Krishnappa et al., 2005
Garlic bulb extract Fungicidal activity
Mustard white rust powdery mildew, Club rot of sarson
Chattopadhayet al., 2005
Ethanol extract of garlic bulb
Inhibits mycelial growth
Root rot & web blight of french bean
Sharma and Gupta, 2003
Garlic, Neem, Onion, Datura, Tulsi, Mint
Antifungal activity
Alternaria of Senna Tetarwal and Rai, 2007
Onion, Ginger, Tulsi, Lantana
Antifungal activity
Penicillium expansum rot on apples
Singh and Sumbali, 2007
Plant material Activity of material Against Disease/ organism Reference
Jatropha extract - Cowpea aphid born mosaic virus
Patel, 1999
Onion, Garlic, Tulsi, Lantana
- Cowpea aphid born mosaic virus
Patel, 1999
Onion, Neem, Turmeric, Ginger
Antibacterial activity
Black gram leaf crinkle virus Thirumalaisang and Rathi, 2007
Garlic, Amaltas, Anola, Castor, Peepal, Marigold, Jatropha, Jamun,
Antibacterial activity
Soft rot of radish Raju et al., 2007
Essential oils of aguaribay, anden thyme. Pepeeine, camoline and pennyroyal
Antibacterial activity
Paenibacillus larvae Fuselli et al., 2006
Ocimum basilicum, Lavandula officinalis
repellent, toxic and ovipositional deterrent
Tetranychus urticae Refaat et al. (2002
Pongamia pinnata seed extract
Acaricidal activity Tetranychus urticae Monikaet al., 2009
Rotenone Varroa destructor Eguaras et al., 2005
Some medicinal plantsSome medicinal plants► Alangium salvifolium Alangium salvifolium (L.f.) Wang.(L.f.) Wang. Local name: Ooduga chettuLocal name: Ooduga chettu Medicinal uses: Medicinal uses: fruits are used as antiometicfruits are used as antiometic► Annona squamosaAnnona squamosa Linn.Linn. Local name: SethafalamLocal name: Sethafalam Medicinal uses: Medicinal uses: leaf paste is applied over joints to get relief leaf paste is applied over joints to get relief
from pain and 5 grams of seed powder along from pain and 5 grams of seed powder along with milk taken against gastric colic with milk taken against gastric colic
► Azadirachta indicaAzadirachta indica A.Juss. A.Juss. Local name: NeemLocal name: Neem Medicinal Uses: Medicinal Uses: leaf smoke is used for the control of leaf smoke is used for the control of
mosquitoes and leaf paste is used to cure skin diseases.mosquitoes and leaf paste is used to cure skin diseases.► Ailanthus excelsaAilanthus excelsa Roxb. Roxb. Local name: Pedda vepaLocal name: Pedda vepa Medicinal uses: Medicinal uses: bark and leaf smoke is used for control of bark and leaf smoke is used for control of
mosquitoesmosquitoes
► Balanites aegyptiacaBalanites aegyptiaca (L.) Del. (L.) Del. Local name: GareLocal name: Gare Medicinal uses: Medicinal uses: small twigs are kept in the ventilators to avoid the small twigs are kept in the ventilators to avoid the
entry of microbes. Dried leaf smoke is used to control the houseflies entry of microbes. Dried leaf smoke is used to control the houseflies inside the home. Fruit pulp is taken orally to control the loose motions.inside the home. Fruit pulp is taken orally to control the loose motions.
► Bambusa arundinacea Bambusa arundinacea (Retz.) Willd.(Retz.) Willd. Local name: VeduruLocal name: Veduru Medicinal uses: Medicinal uses: stem stripes are used to bind the fractured bonesstem stripes are used to bind the fractured bones..► Calotropis procera Calotropis procera (Ait.) Aitf.(Ait.) Aitf. Local name: jelladuLocal name: jelladu Medicinal uses: Medicinal uses: leaves are pounded with caster oil and banded over leaves are pounded with caster oil and banded over
knee joints to get relief from joint painknee joints to get relief from joint pain► Eucalyptus globulusEucalyptus globulus Local name: SafedaLocal name: Safeda Medicinal uses: Medicinal uses: Externally for athlete’s foot disease, dandruff, Externally for athlete’s foot disease, dandruff,
inhalation for asthmainhalation for asthma► Ginkgo bilobaGinkgo biloba Local name: ginkgoLocal name: ginkgo Medicinal uses: Medicinal uses: Relieves asthma, treat cerebral disordersRelieves asthma, treat cerebral disorders► Vitex negundo Vitex negundo Local name: Local name: VaviliVavili Medicinal uses: Medicinal uses: Malaria, poisonous bites, leukemia, reduce blood Malaria, poisonous bites, leukemia, reduce blood
pressurepressure
Advantages of Advantages of BiopesticidesBiopesticides
Difficult for insects to develop resistance to these Difficult for insects to develop resistance to these pesticidespesticides
Safe to natural enemies and higher organisms Safe to natural enemies and higher organisms Biodegradable :Biodegradable : Rapid degradation of the active Rapid degradation of the active
ingredient make it more acceptable. ingredient make it more acceptable. In cotton residues of In cotton residues of Azadirachtin dissipated within 12 hr when applied @ 20 & Azadirachtin dissipated within 12 hr when applied @ 20 & 40 ppm concentrations40 ppm concentrations (Indumathi, 2002) (Indumathi, 2002)
Cheaper, renewable, can be handled safelyCheaper, renewable, can be handled safely Often have other uses like household insect repellents or Often have other uses like household insect repellents or
are plants with medicinal properties are plants with medicinal properties Most are compatible with insecticides and microbial Most are compatible with insecticides and microbial
agentsagents There is great demand for residue free cotton garments, There is great demand for residue free cotton garments,
fruits, vegetables and beverages, large scale utilization of fruits, vegetables and beverages, large scale utilization of botanical pesticides will certainly help us in meeting botanical pesticides will certainly help us in meeting international standards of quality and safety in these international standards of quality and safety in these productsproducts
Disadvantages ofDisadvantages of BiopesticidesBiopesticides
Slow effectSlow effect Lack persistence and wide spectrum activityLack persistence and wide spectrum activity Rapidly degraded by UV light so residual action is Rapidly degraded by UV light so residual action is
slow. slow. Half lives of pyrethrins on tomato and bell Half lives of pyrethrins on tomato and bell pepper fruits were 2 hrs or lesspepper fruits were 2 hrs or less (Antonious, 2004) (Antonious, 2004)
Effective dose is higher i. e. 30 ml/10L especially in Effective dose is higher i. e. 30 ml/10L especially in neemneem
Seasonal availability of plant products indicates the Seasonal availability of plant products indicates the need for their storageneed for their storage
Not easily available everywhereNot easily available everywhere Poor water solubility and are generally not Poor water solubility and are generally not
systemic in naturesystemic in nature All products applied followed by growers have not All products applied followed by growers have not
been scientifically verifiedbeen scientifically verified
1. Inherently less harmful than conventional pesticides
2. Suppress, rather than eliminate, a pest population, so leaves the vulnerable population to natural enemies
3. Effective and often quickly biodegradable and present no residue problems
4. Mostly self perpetuating
5. Safe for non target organisms and human
Conclusion
Future prospective
Ecological studies on dynamics of diseases in insect populations are necessary
Efforts should be made to minimize the loss of infectivity of certain pathogens due to photoinactiavtion
Extension work needs to be geared up among the farming community to make them aware about the use and benefits of biopesticides
Biotechnological approaches could be useful for obtaining bioactive products on large scale
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