Conservation implications of habitat transformation

and pesticides on arthropod diversity and abundance

in the Elgin district, southwestern Cape Province,

South Africa

A.B.R. Witt

Percy FitzPatrick Institute of African Ornithology

University of Cape Town

Rondebosch, 7701

Cape Town, South Africa.

Supervisors: Prof Tim Crowe, Dr Rob Little

Thesis submitted in partial fulfilment of the requirements for the degree of Master of

Science in Conservation Biology, University of Cape Town.

June 1994

The copyright of this thesis rests with the University of Cape Town. No

quotation from it or information derived from it is to be published

without full acknowledgement of the source. The thesis is to be used

for private study or non-commercial research purposes only.

Univers

ity of

Cap

e Tow

n

I

Conservation implications of habitat transformation and pesticides on arthropod

diversity and abundance in the Elgin district, southwestern Cape Province,

South Africa

by

A.B.R. Witt

FitzPatrick Institute, University of Cape Town

Rondebosch 7700, South Africa

ABSTRACT

The impact of habitat transformation on arthropod taxa and the effect of

pesticides on non-target arthropods generally has been ignored, especially in

southern Africa. In this study the arthropod diversity of a patch of natural

vegetation (fynbos) is compared to that of two apple orchards, one under

intensive pest management ("sprayedIf) and the other exposed to fungicide

treatments only ("unsprayed"). Samples obtained from pitfall traps and a D­

Vac Sampler revealed that 221 insect species or morphospecies were present in

the fynbos compared to 152 and 106 in the unsprayed and sprayed orchards,

respectively. Comparative spider (Araneae) species richness was 38

.morphospecies in fynbos, 24 in unsprayed and 17 in sprayed orchards.4

Hemipterans, hymenopterans, and orthopterans were' the most speciose insect

taYtJI in fynbos. The number of coleopteran species or morphospecies were

sifhilar for all sites, whereas the other insect orders were represented by more

taxa, in the unsprayed compared to the sprayed orchard. The introduced, ,

Argentine ant Linepithema humile was the most abundant species in both

orchards. Diplopodsand especially isopods were more abundant in the

unsprayed compared to the sprayed orchard. Arthropod species richness and

abundance was influenced by the presence of host plants, the structural diversity

of the vegetation, the availability of microhabitats and the intensity of pest

management. Although transformed habitats have lower species richness than

areas of natural vegetation, arthropod diversity in apple orchards can be

enhanced, by..increasingthestructural and plant diversity of the cover crop and

by using selective insecticides.I I

1

INTRODUCTION

The greatest threat to global biodiversity is habit alteration and destruction

brought about by the expansion of human populations and their activities

(perrings etal. 1992; Kim 1993; Samways 1993). If current trends continue it

is estimated that one million animal species will become extinct by the year

2000 (Myers 1980). The majority of extinctions would occur within the

arthropoda since they are the most diverse and abundant taxa in the animal

kingdom (Kim 1993). From an ecological perspective this may have far

reaching ramifications, since insects play an important role in the provision of

ecological services like .pollination, decomposition; seed dispersal, biological

control and as a food source for a myriad of other organisms (Majer 1987;

Wilson 1987; Samways 1993).

Unfortunately, due to taxonomic impediments (Samways 1993), it is not known

how many insect species, with the exception of butterflies, recently have

become extinct in southern Africa. Agricultural development and alien invasive

plant species in the Cape Floristic Region not only pose the largest threat to

indigenous plant species (Rebelo 1992), but also their associated insect fauna.

If one considers that 68% of the more than 8500 indigenous plant species in the

Cape Floristic Region are endemic. (Bond and Goldblatt 1984), it becomes

apparent that the region probably contains a myriad of endemic insect taxa.

-Lycaenids, endemic to the region are threatened, probably because they require.~

the presence of a specific host ant and plant (Hennig and Hennig 1989).

rever, .not all phytophagous insects are restricted to a single host, since

many harbivorous taxa and feed on both indigenous and introduced plants (Liss

letal. 1986). These generalist taxa can colonize and persist in cultivated areas

with .a host of other insects including predators, parasitoids, detritivores,

coprophagous, saprophagous and mycophagous insects provided their life

history strategies are adapted to the conditions and resources available in these

habitats (Liss et al. 1986). Arthropod diversity and abundance within

transformed habitats, especially agricultural areas, is influenced by the

architecture or structural diversity of the crop plant itself (Lawton 1983), the

variety or diversity of crops within an area (Perrin and Phillips 1978; Tonhasca

1993), the abundance, diversity and management of noncrop vegetation (Morris

and Lakhani 1979; Altiera and Schmidt 1985; Liss 1986; Sheehan 1986; GoodI

and Giller 1991), the distance from and the diversity of adjacent vegetation

(Liss et ale 1986; Whalon and Croft 1986; Szentkiralyi and Kozar 1991) and the

intensity of pest management (Mansour et al. 1981; Samways 1981; Basedow et

2

al. 1985; Shires 1985; Cole 1986; Szentkiralyi and Kozar 1991). In the

southwestern Cape the abundance and diversity of apple pests and, to a lesser

extent, their natural enemies is generally known (K.L. Pringle pers. comm.).

However, the impact of various management practices on other arthropods in

apple orchards has not been ascertained. In addition, few studies have

attempted to describe the total insect fauna of apple orchards (Kozar 1987 in

Szentkiralyi and Kozar 1991). The alms of this study are to compare arthropod,

particularly insect, diversity between Mountain fynbos, a vegetation type in the

Cape Floristic Region, with that of apple orchards, under high and low intensity

pest management.

MATERIALS AND METHODS

Study area

The study area was located on the Elgin Experimental Farm, approximately 1

km north of Grabouw (34°05'S;19°05'E), southwestern Cape Province, South

Africa. The study site consisted of two adjacent 31-year old apple orchards

(cultivar Granny Smith), similar in size, and a tract of Mountain Fynbos

approximately 0.75 hectares in extent (Fig.1). One of the apple orchards

(hereafter referred to as unsprayed) received only fungicide treatments whereas

the other orchard received an additional 12 insecticide treatments (hereafter

'referred to as sprayed) between 10 October 1993 and 3 January 1994 (Appendix~

1). Both apple orchards were identical in terms of management of the cover

f'

cr · which included mowing and the use of herbicides. The fynbos patch,

aIt ough small in extent, was relatively undisturbed and was similar to large,

pnfragmented tracts in the general district.

Sampling methods

Pitfall traps and the Dietrick Vacuum (D-Vac) Sampler (Dietrick et al. 1960)

were used to sample arthropods. Pitfall traps are commonly employed to obtain

a rapid census of the epigaeic invertebrate fauna (Majer and Greenslade 1988),

while Dvvac samples are particularly efficient at sampling hemipterans, adult

dipterans and adult hymenopterans (Johnson et al. 1957). To reduce any

possible edge effects.vsamples.iathe .apple orchards were only taken from the

area surrounding 72 trees (72 x 36 m) in the centre of each orchard. An area

was selected for sampling, similar in size to that in the orchards, in the centre of

the fynbos patch (Fig. 1).

3

Eight of the 72 trees in each orchard were selected at random. Four pitfall traps

were placed at 75, 150,225 and 360 ern from the base of each selected tree, at

90° to each other, using the orientation of the tree row as the main reference

line (0°) (pig. 1). However, since insect diversity is influenced by a

combination of factors including shading, aspect and the type of ground cover

the traps were rotated as shown in Table 1. Eight points were selected at

random in the fynbos patch. Trap placement was similar to that used in

orchards. Each pitfall trap consisted of a test tube (25 x 150 mm) within a

plastic pipe which was sunk into the ground so that the lip of the tube was flush

with the soil surface. Each tube was filled with 40 ml of water and

approximately three drops of detergent to break the water tension. Alcohol was

not used since it may act asa repellant to certain arthropod taxa (Southwood

1966). Pitfall traps were set up at least one week before sampling commenced

and sealed with a rubber stopper when not in use. Each trapping period

extended over 10 days, after which all the invertebrates were collected and

placed in vials containing alcohol. Pitfall traps remained sealed for

approximately 20 days before they were reopened for another 10-day period.

The traps were surveyed three times over a 50-day period on 24 November, 15

December 1993 and 4 January 1994.

Fifteen Dsvac samples were taken in each of the orchards and in the fynbos

"patch.' Five samples were taken from randomly selected 1m2 quadrats, directly4

under the trees, between the trees within a row and in the work area between

thfows., The ground cover under the trees consisted mainly of leaf litter, the

area between the trees within a row was mainly bare with some leaf litter, while

Ithe work row had a weed and grass cover. Sampling was done between 10hOO

and lShOO' on warm and calm days when insects were most active. Since insect

activity is main~y influenced by temperature and other abiotic factors, five

consecutive samples were taken in a particular site before moving to another

site. The sites and'.quadrats were sampled in random order. All samples

collected, together with the debris, were placed in separate plastic bags. Filter

paper, dipped in ethyl acetate was placed in each bag to kill all arthropods.

Samples were collected on 14 November, 5 December and 24 December 1993.

Identification (All arthropods, excluding collembolans, were sorted and identified to class or

order level. Aranids and insects were identified to species or morphospecies

but, insects were the only taxa identified to family level. Morphospecies were

4

generally based on external morphology only, although genitalia were used in

determining morphospecies in taxa like ground beetles where species are known

to be very similar morphologically. Dimorphic taxa like dermapterans and

polymorphic . taxa like aphids and formicides were split into separate

morphospecies as were taxa which exhibited holometabolous development.

Many insect nymphs could not be associated with any adult taxa collected

during the study and were therefore classified as morphospecies. Although the

use of morphospecies has been criticised (Kim 1993), the use of recognisable

taxonomic units (RTU's) in rapid biodiversity assessments has its merits

especially during preliminary surveys (Oliver and Beattie 1993). In addition,

particular life stages within a single species may be more sensitive to habitat

transformation and pesticides than other instars. If one also considers the

taxonomic impediment (Samways 1993) and the need to rapidly estimate

biodiversity and the effect of habitat destruction (Oliver and Beattie 1993) the

use of morphospecies is warranted. In the remainder of the text morphospecies

will be referred to as species unless stated otherwise. The nomenclature for

insects follows that of Scholtz and Holm (1985), and voucher specimens are

lodged in the Department of Entomology, University of Stellenbosch, South

Africa.

Dataanalysis'The .data obtained from pitfall traps and D-vac samples were combined for all

4

analyses. Correspondence analysis (Greenacre 1986) was used to compare thethi sites-in terms of ~e number of species in each of ~e insect orders

sampled. Psocopterans, trichopterans, neuropterans and phasmids were grouped

together since they were restricted to only one of the three sites.

Correspondence analysis is useful since it graphically illustrates which taxa are

contributing to the separation of sites.

Diversity profiles were used to compare insect diversity in the three study sites.

The method used by De Kock et ale (1992) and devised by Patil and Taille

(1976, 1979) has many desirable properties in that three diversity indices which

are popular amongst ecologists (Dennis et ale 1979) can be graphically

5

represented on the same pair of axes. Dennis et at. (1979) use the following

expression to generate a series of diversity indices:

N86 = L Pi(1 - P,.6)/13, i = 1,2,•... N,

i=l

where N = number of species,

Pi = proportion of individuals in species i, and

13 = measure of the weight attached to eveness.

If 13 is in the range -1 to + 1, then for

13 = -1, .6-1 = N - 1, or the species count, and for

13 approaching 0,.60 = -LP;lnPi , or the Shannon-Weaver Diversity

Index and for

13 = +1,.6+1 = 1 - LP,2, or the Simpson's Species Evenness Index.

The index was modified to standardise it to a scale of between 0 and 1 as

follows (K.L. Pringle pers. comm.):T

.613 = 1 LPi(1-P,.6)/13, i= 1,2,....T,[1 - (P6]/13 i=l

whereT =:= the total number of species recorded during the study period.

U~,g thestandardized values one can compare species richness (left side of

grl.t>h) and species eveness (right side of graph) between the insects and aranids;- !f~

in sprayed, unsprayed and fynbos sites. The contribution of intermediate and

'dominant species within the sites can also be compared (De Kock et al. 1992).

In the' present analysis the most dominant species, the introduced Argentine ant

Linepithema humile Mayr was included in one diversity profile and excluded in

the other to ascertain what effect this species was having on species eveness in

the three communities.

RESULTS

Fourteen orders, 113 families, and 354 species or morphospecies were collected

in the apple orchards and fynbos patch over a period of two months (Table 2).

Hymenopterans and dipterans were represented by the most number of families

(Appendix 2). The most speciose orders were the Hemiptera and Coleoptera

which together accounted for more than 51% of the total numbers of species

sampled. The Argentine ant was numerically the most abundant species with

6

over 66% of all insects sampled belonging to this invasive alien. Of the other

arthropod taxa sampled, isopods were the most abundant (Table 2).

The fynbos patch was the most species rich with 221 insect species compared to

the 152 and 106 species recorded in the unsprayed and sprayed orchards,

respectively. There were more orthopteran, hemipteran, hymenopteran and to a

lesser extent, phasmid, mantid, thysanopteran and psocopteran species in the

fynbos site compared to both orchards (Table 3). These observations are

supported by correspondence analyses which indicate a close association

between the fynbos site and the most speciose insect orders found in the fynbos

patch (Fig. ~). Of the 221 species in the fynbos 32% were hemipterans.

Lygaeids and cicadellids were the most speciose hemipteran families (Appendix

2). Of the 62 hymenopteran species sampled in the fynbos patch 25 were

parasitoids compared to only 11 and 12 in the unsprayed and sprayed orchards,

respectively. Although most taxa in the fynbos had higher species richness,

dermapterans and aphids were two insect orders with more species in the

unsprayed orchard. Most taxa in the sprayed orchard had fewer species than in

the other two sites with the exception of adult carabids and staphylinids.

However, the total number of coleopteran species was similar for all three sites

." (Table 3). The close association of coleopterans with the sprayed orchard in the

correspondence analysis (Fig. 2) thus should be viewed with caution.

A

Almost three and four times as many individual insects were sampled in the

una'rayed .orohard compared to the fynbos and sprayed sites, respectively

('~ble 3). Hymenopterans, coleopterans, dipterans and dermapterans were the

most abundant taxa in the unsprayed area while hemipterans and lepidopteransI

were ~orecommon in the fynbos. Coleopterans and dipterans were more

abundant in the sprayed orchard than in fynbas (Table 3). Other arthropod taxa

like Isopods, diplopods and chilopods were more numerous in the unsprayed

orchard with acarides being more common in fynbos (Table 3). Although

spiders were numerically more abundant in the unsprayed orchard, 38 species

were sampled in the fynbos compared to the 24 and 17 in the unsprayed and

sprayed orchard, respectively.

Species diversity is a combination of species number and their relative(

abundance. The species richness index confirms the earlier results that more

insect species were sampled in the fynhos patch. In addition, the species

eveness index shows that the fynbos patch is not dominated by any species

7

unlike the orchard insect community which had very low eveness indices (Fig.

3A). However, removal of L. humile workers from the analysis increased the

species eveness indices for.both orchards indicating the complete dominance of

this species in transformed habitats (Fig. 3B). Aranids were, most speciose in

fynbos and had the.most equal distribution of individuals per species, hence the

larger species eveness index compared to the orchards (Fig. 3C).

DISCUSSION

The absence of host plants, a reduction in the structural diversity of vegetation,

the availability of microhabitats, and pest management practices were the main

factors which influenced arthropod species richness and abundance in the three

study sites. Many species which were abundant in the fynbos site were rare or

absent in the transformed habitats. The absence of host plants and a reduction

in the structural diversity of the vegetation within the orchard environment may

have been responsible for this finding. Many insects are host plant specific

(Hennig and Hennig 1989), often exploiting very restricted parts' of their host

(Addicott 1978; Stiling 1980; Lawton 1983). The structural diversity of host

and other plant species in the fynbos patch may also have contributed to

arthropod species richness. Increased vertical stratification in the vegetation

,. increases .the availability of various resources and living space (Lawton 1983).

This was confirmed.by Morris and Lakhani ·(1979) who found that hemipteran

'species richness was reduced on grazed and experimentally mown chalk4

grasslands. Foliage-dwelling aranids also are sensitive to cover crop

~agemeIit since itresults in the destruction of microhabitats and egg-sacs

(~yffeler and Benz 1987). Taxa like formicids which generally do not require

,Plants for food, shelterand/or oviposition sites were also less speciose in the

orchard environment. Of the 16 species (not morphospecies) of formicids

recorded in the f~nbos patch, nine were sampled in the unsprayed orchard. This

is in agreement with Altieri and Schmidt (1986) who found more formicid

species in abandoned than managed orchards. Fungicides probably also

contributed to lower species richness in the unsprayed orchard (Theiling and

Croft 1989).

Disturbed. habitats often consist of a single. or a small number of extremely

abundant taxa.. A number of factors may be responsible for this observation.I

Monocultural food-plant patches supply more favourable conditions to apple

pests (Szentkiralyiand Kozar 1991), "release" from competitors and predators

generally result.in population explosions in most species, and microhabitats in

8

transformed environments often provide the optimum conditions for an array of

opportunistic arthropod taxa. Either one or all of these factors contributed to

the abundance of most taxa in the unsprayed orchard. A large amount of leaf

litter and the fact that orchards were frequently irrigated provided the ideal

habitat for arthropods prone to dessiccation. The Argentine ant which was the

most abundant species in the orchards, favours habitats with high ambient

moisture (Witt 1993), while aphids and some curculionid taxa are crop pests

which thrive in situations wheir there natural enemies and/or competitors are

absent. Many taxa are also attracted to rotting plant material which is more

abundant in the orchard environment.

Insecticides applied in orchards generally are not specific and have a large

impact on non-target species. The impact of insecticides on certain species is

influenced by the behaviour, activity patterns, physiology, and location of the

organism at the time of application (Jepson 1989). The method of application

and the type of chemical used may have different impacts on the arthropod

community. Arthropods residing on the upper strata of vegetation would be

more exposed to the toxic effects of pesticides than would those under leaf litter

or in the soil. Although this is confirmed by the large numbers of cydnids,

staphylinids and carabids in the sprayed orchard, taxa which inhabit leaf litter

like diplopods, and specifically isopods, were virtually absent from the sprayed

~ , 'environment. The results from this study are contrary to other research which4

has found that staphylinid and carabid populations are reduced by the use of

pe~cides'(Dunning ~t al. 1975; Vickerman and Sunderland 1977; Good and

G~ler 1981; Shires 1985), although not all insecticides have a negative effect on

jhese predatory beetles (Basedow et al. 1985).

Arthropod species richness and abundance in apple orchards can be enhanced by

increasing the structural diversity of the cover crop and by applying more

selective insecticides; In addition, pest resistance and the cost involved in

developing new pesticides (Dover and Croft 1985) has resulted in a move

toward integrated pest management (IPM), which includes less disruptive

methods of pest control, whereby parasitoids, predators and pathogens are used

in conjunction with other pest control measures to control insect crop pests.

According to A~ltieri and Schmidt (1985), the number of enemy species can be

enhanced by increasing the diversity of the cover crop. Natural enemy species

also were more abundant in orchards surounded by diverse vegetation

(Szentkiralyi and Kozar 1991). Although, this could not be confirmed from

9

f

results obtained in this particular study, it was evident that parasitoids were

more speciose and abundant in the fynbos patch. Brown et ale (in Szentkiralyi

and Kozar 1991) found twice as many natural enemies in abandoned orchards

compared to 'managed apple orchards.

The retention of patches of indigenous vegetation adjacent to apple orchards

should. be encouraged since they remain a source of potential colonists. Various

life history stages of some arthropod taxa within the orchard may also be

dependent on the fynbos patch. In addition, many insect taxa in southern Africa

are endemic to the region (Samways 1993) and should be conserved. Future

research should concentrate on the effectiveness of orchard cover crop

diversification in order to improve the habitat for all arthropods, particularly

predatory and parasitic taxa. The importance of fynbos patches as a source pool

for beneficial insects should also he addressed.

10

ACKNOWLEDGEMENTS

I would like to thank Miss A. den Breeyen for assisting with the collection of

data. Thanks also to Dr.R. Geertsema, Dr. R. G. Robertson and Dr. S. van

Noord for helping with the identification of taxa. Special thanks to Mr. C.

Louw of the Elgin Experimental farm and the African Gamebird Research and

Development Trust (AGRED) for financial and logistical support. My thanks

also to Dr. R.M. Little and Dr. P. Ryan for valuable comments during the

course of the project. I am also grateful to the staff of the Department of

Entomology, University of Stellenbosch who made their facilities available

during my research.

11

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d -

Shires,S.W,' 1985. A comparison of the effects of cypermethrin, parathion-

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15

Szentkiralyi, F. and F. Kozar. 1991. How many species are there in apple

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utersityof Stellenbosch.,; ~/

16

I

Table 1. The distance of pitfall traps from

the base of the tree and their corresponding

orientation using the orchard tree row as a

reference line (0 0) .

Tree no. Orientation

0 0 90 0 1800 270 0

1 and 5 75 150 225 300

2 and 6 300 75 150 225

3 and 7 225 300 75 150

4 and 8 150 225 300 75

17

Table 2. The abundance of arthropod taxa sampled during the study period

(ND = no data).

18

Taxa Families Species Abundance

Hymenoptera 28 62 10565Hemiptera 18 95 1213Coleoptera 21 86 830Diptera 23 44 689Orthoptera 6 17 133Dermaptera 2 6 124Lepidoptera 7 26 66Phasmatodea 1 3 8Mantodea 1 3 7Neuroptera 1 1 7Blattodea 1 4 5Thysanoptera 1 4 4Psocoptera 2 2 3Trichoptera 1 1 1

... 'SUBTOTAL 113 354 13655~

~~da ND ND 4449plopoda ND ND 534

,Araneae ND 58 5271

Chilopoda ND 307NO

Acarina ND ND 253Scorpionida ND NO 2

TOTAL 113 412 19727

Table 3. The number of species in each arthropod taxa and their abundance in

the fynbos (F), unsprayed (U) and sprayed (S) sites (ND = no data).

19

Taxa Species

F U S

Abundance

F U S

Hymenoptera 44 22 16 1820 7197 1548Hemiptera 70 39 17 943 192 78Coleoptera 46 40 44 131 386 313Diptera 21 23 16 120 290 279Orthoptera 15 5 3 44 71 18Dermaptera 2 6 2 3 118 4Lepidoptera 11 12 6 31 20 15Phasmatodea 3 0 0 8 0 0Mantodea 3 1 0 6 1 0Neuroptera 0 1 0 0 7 0Blattodea 1 2 1 1 3 1Thysanoptera 3 0 1 3 0 1

"'- .Psoeoptera 2 0 0 3 0 0Trichoptera 0 1 0 0 1 0

SrTOTAL 221 152 106 3112 8286 2257

.Isopoda ND ND ND 48 4400 1I

Diplopoda ND ND ND 13 489 32Araneae 38 24 17 138 240 149Chilopoda ND ND ND 8 184 115Acarina 'iND ND ND 189 18 46Scorpionida ND ND ND 2 0 0

TOTAL 259 176 123 3510 13617 2600

Appendix 1. List of pesticides sprayed in both orchards and the pests which they have been

registered to control.

Date Orchard Chemical name Trade name Pests

6/10 Both Pyrifenox Dorado Powdery mildew

Fusicladium

Both Mancozeb Dithane M45 Powdery mildew

Fusicladium

13/10 Both Pyrifenox Dorado Powdery mildew

Fusicladium

Both Mancozeb DithaneM45 Powdery mildew

Fusicladium

Sprayed Azinphosmethyl Azinphos Codling moth

Leaf rollers

Bryobia mite

20/10 Both Mancozeb Dithane M45 Powdery mildew

Fusicladium

Both Bupirimate Nimrod Powdery mildew

25/10 Sprayed Azinphosmethyl Azinphos Codling moth

Leaf rollers

Bryobiamite

27/10 Both Mancozeb DithaneM45 Powdery mildew

Fusicladium

Both Bupirimate Nimrod Powdery mildew

03/11 Sprayed Captab Kaptanflo Postharvest decay

Fusicladium

Powdery mildew

Sprayed Fenvalerate Agrithrin Codling moth

Snout beetle

Sprayed Bupirimate Nimrod Powdery mildew

Sprayed Azinphosmethyl Gusathion Codling moth

Leaf rollers

Bryobia mite

17/11 Both Mancozeb DithaneM45 Powdery mildew

Fusicladium

Both Pyrifenox Dorado Powdery mildew... Fusicladium

Sprayed Carbaryl Sevin Codling moth

IMealybug

Leaf rollers

~v Thinning

Sprayed Azinphosmethyl Gusathion Codling moth

LeafrollersI Bryobia mite

01112 Both Mancozeb DithaneM45 Powdery mildew

Fusicladiuni

Both Pyrifenox Dorado Powdery mildew

Fusicladium

Sprayed Azinphqsmethyl Gusathion Codling moth

Leaf rollers

Bryobia mite

13/12 Sprayed Vamidothion Kilval Woolly aphid

20/12 Both Mancozeb Dithane M45 Powdery mildew

Fusicladium

Sprayed Azinphosmethyl Gusathion Codling moth

Leaf rollers

Bryobia mite

03/01 Both Mancozeb DithaneM45 Powdery mildew

Fusicladium

Sprayed Azinphosmethyl Gusathion Codling moth

Leaf rollers

Bryobia mite

Appendix 2. The abundance and species richness of arthropod taxa collected with pitfall traps (P) and a D-Vac Sampler (V) in

fynbos (F), and unsprayed (U) and sprayed (S) apple orchards in the Elgin district (ND = no data)

SPECIES RICHNESS ABUNDANCE

F U S FYNBOS UNSPRAYED SPRAYED

TOTAL P+V P V P V P V

PYYLUM ARTHROPODASUBPHYLUM CHELICERATACLASS ARACHNIDA*ORDER ARANEAE 58 38 24 17 76 62 193 47 121 28*ORDER ACARINA ND ND ND ND 189 0 17 1 46 0*ORDER SCORPIONIDA ND ND ND ND 2 0 0 0 0 0

SUBPHYLUM MANDIBULATACLASS CRUSTACEA

*ORDER ISOPODA ND ND ND ND 46 2 4013 387 1 0CLASS DIPLOPODA ND ND ND ND 12 1 313 176 27 5CLASS CHILOPODA ND ND ND ND 8 0 178 6 109 3CLASS INSECTA

*ORDER BLATTODEAFamily Blattidae 1 1 2 1 1 0 2 1 1 0

*ORDER MANTODEAFamily Mantidae 3 3 1 0 0 6 0 1 0 0

*ORDER DERMAPTERAFamily Labiduridae 5 0 5 2 0 0 101 8 4 0Unknown family 2 2 1 0 2 0 9 0 0 0*ORDER ORTHOPTERA

SUBORDER ENSIFERAFamily Stenopelmatidae 1 1 0 0 2 0 0 0 0 0Family Tettigoniidae 1 1 0 0 0 2 0 0 0 0Family Gryllidae 2 2 2 2 7 3 59 6 16 0SUBOROOR"CAEiJFERA '

Family Pamphagidae 1 1 0 0 0 3 0 0 0 0

)'amil)' Lentulidae !. 5 5 0 0 1 17 0 0 0 0Family Acrididae ;: 7 5 3 1 1 8 4 2 1 0-*ORDER:~PHASMA'f, ,DEA

Family Phasmidae 3 3 0 0 0 8 0 0 0 0*ORDER ~PSOCOP:fERA

SUBbRDEk PSOCOMORPHA

Family Ectopsocidae r- 1 0 0 1 0 0 0 0 0SUBORDER TROGIOMORPHA

"

Family Trogiidae 1 1 0 0 1 0 0 0 0 0*ORDER HEMIPTERASUBORDER HETEROPTERA

Family Isometopidae 1 0 1 0 0 0 1 0 0 0Family Tingidae 1 1 0 0 1 0 0 0 0 0Family Reduviidae 10 8 3 5 8 9 1 4 4 6Family Stenocephalidae 1 1 0 0 3 0 0 0 0 0Family Pyrrhocoridae 3 0 1 3 0 0 0 1 5 6Family Lygaeidae 28 21 12 3 179 352 4 22 4 16Family Cydnidae 2 1 2 1 3 0 3 0 28 1Family Pentatomidae 4 3 0 1 0 5 0 0 0 1SUBORDER HOMOPTERA

Family Delphacidae 2 2 0 1 0 2 0 0 1 1Family Achilidae 2 2 0 0 0 2 0 0 0 0Family Dictyopharidae 1 1 0 0 0 2 0 0 0 0

Appendix 2 (cont.)

SPECIES RICHNESS ABUNDANCEF U S FYNBOS UNSPRAYED SPRAYED

TOTAL P+V P V P V P V

Family Cixiidae 1 1 0 0 0 1 0 0 0 0Family Tropiduchidae 3 3 1 0 6 184 0 1 0 0Family Flatidae 2 2 0 0 1 20 0 0 0 0Family Aphrophoridae 2 2 0 0 0 10 0 0 0 0Family Cicadellidae 24 18 11 1 31 119 12 24 1 0Family Psyllidae 1 0 1 0 0 0 1 0 0 0Family Aphididae 8 4 7 2 5 0 62 56 3 3*ORDERTHYSANOPTERASUBORDER TUBULIFERA

Family Phlaeothripidae 4 3 0 1 3 0 0 0 1 0*ORDER NEUROPTERA

Family Hemerobiidae 1 0 1 0 0 0 0 8 0 0*ORDER COLEOPTERALARVAL COLEOPTERASUBORDER ADEPHAGA

Family Carabidae 7 4 2 4 9 0 2 0 8 0SUBORDER POLYPHAGAFamily Elateridae 1 1 1 1 3 0 3 0 2 0Family Dermestidae 1 1 0 0 4 0 0 0 0 0Family Tenebrionidae 4 2 1 2 2 0 1 0 5 0Family Curculionidae 1 0 0 1 0 0 0 0 3 0ADULT COLEOPTERASUBORDER ADEPHAGA

Family Carabidae 16 9 10 11 17 2 43 12 89 6SUBORDER POtYPHAGAFamily Histeridae 2 1 1 0 1 0 2 0 0 0Family Ptiliidae, 1 1 0 0 1 0 0 0 0 0Family Staphylinidae; 10 3 4 6 3 0 4 1 53 2Family ceraiocanthidae 1 1 0 0 1 0 0 0 0 0~amily Scarabaeidae

I5 3 3 2 8 1 13 1 11 1

Family Byrrhidae 1 1 1 1 1 0 0 1 0 1Family'Elhteridae :-i-,I 1 1 1 0 1 0 12 14 0 0Family Cantharidae 1 1 0 0 0 1 0 0 0 0Fam~y MelJridae I 2 1 1 1 0 2 0 1 0 1Family Anebiidae 1 0 0 1 0 0 0 0 0 2Family Nitidulidae 4 2 3 2 1 1 19 7 2 3Family Corylophidae i. 0 0 1 0 0 0 0 4 0Family Coccinellidae 8 4 3 3 2 8 1 4 0 4Family Lathridiidae 1 0 0 1 0 0 0 0 4 0Family Tenebrionidae 5 3 3 2 2 2 130 8 69 0Family Anthicidae 2 1 2 0 0 9 4 13 0 0Unknown family 1 1 0 1 7 0 0 0 1 0Family Chrysomelidae 5 2 1 3 0 39 8 43 3 0Family Curculionidae 5 3 3 2 0 3 15 24 16 24*ORDER DIPTERA

LARVAL DIPTERA

SUBORDER CYCLORRHAPHADivision AschizaFamily Syrphidae 2 1 1 0 1 0 2 0 0 0

Appendix2 (cont.)

SPECIES RICHNESS ABUNDANCEF U S FYNBOS UNSPRAYED SPRAYED

TOTAL P+V P V P V P V

ADULT DIPTERASUBORDERNEMATOCERA

Family Tipulidae 1 0 1 0 0 0 2 0 0 0Family Chironomidae 2 1 1 1 1 0 1 0 1 0Family Sciaridae 2 2 1 2 11 0 5 0 18 5

Family Mycetophilidae 2 1 2 0 0 1 0 3 0 0

Family Cecidomyiidae 1 1 0 0 31 0 0 0 0 0SUBORDERBRACHYCERAFamily Asilidae 1 1 0 0 0 1 0 0 0 0

Family Therevidae 2 2 0 0 0 3 0 0 0 0

Family Dolichopodidae 1 1 0 0 6 0 0 0 0 0

SUBORDERCYCLORRHAPHA

Division Aschiza

Family Phoridae 1 1 1 1 47 0 213 3 179 2Family Pipunculidae 1 1 0 0 0 1 0 0 0 0

Family Tephritidae 3 2 1 0 1 1 0 1 0 0Family Sepsidae 2 0 2 0 0 0 13 7 0 0Family Sphaeroceridae 3 2 2 2 7 0 12 0 22 0Family Milichiidae 1 0 0 1 0 0 0 0 0 1Family Drosophilidae 3 0 2 2 0 0 2 0 2 0Family Ephydridae 1 0 1 0 0 0 1 0 0 0Family Chloropidae 5 2 3 3 4 0 2 4 20 15Family Fanniidae 1 0 1 0 0 0 1 0 0 0

Family Muscidae 1 0 1 0 0 0 1 0 0 0Family Anthomyiidae 2 0 0 1 0 0 0 0 2 0Family Sarcophagidae 3 0 3 2 0 0 16 0 12 0Unkriown family 3 3 0 0 0 4 0 0 0 0ORDER TRJ;CBOPTERA

Family Leptoceridae 1 0 1 0 0 0 1 0 0 0

"oJID.E& LEPIDO?LARVAL LEPIDOPT

SUBORDER DITRY •AFamily Pyralidae 9 0 7 2 0 0 11 1 3 0Family Psychidae I 5 5 0 0 5 18 0 0 0 0Famlly No~dontidae 1 0 1 0 0 0 1 0 0 0Family Noctuidae 3, 0 2 1 0 0 3 1 0 0ADULT LEPIDOPTERASUBORDER DITRYSIAFamily Tineidae 1 0 0 1 0 0 0 0 1 0Family Gracillariidae 2 2 0 0 1 6 0 0 0 0Family Yponomeutidae 3 2 1 0 0 2 1 0 0 0Family Noctuidae 2 2 1 2 2 1 1 1 8 2*ORDER HYMENOPTERASUBORDER SYMPHYTA

Family Tenthredinidae 1 1 0 0 1 0 0 0 0 0SUBORDER APOCRITA

Family Formicidae 19 18 11 4 1611 125 6409 771 1463 68Family Braconidae 3 0 2 2 0 0 2 1 2 1Family Ceraphronidae 4 2 1 1 3 0 0 1 1 0Family Diapriidae 3 1 3 1 1 0 5 0 0 1Family Scelion,!dae 12 7 2 3 43 0 4 0 6 0

Appendix 2 (cont.)

SPECIES RICHNESS ABUNDANCE

F U S FYNBOS UNSPRAYED SPRAYED

TOTAL P+V P V P V P V

Family Cynipidae 1 0 1 0 0 0 1 0 0 0

Family Eucoilidae 1 0 1 0 0 0 0 1 0 0

Family Mymaridae 1 . 1 0 0 1 0 0 0 0 0

Family Torymidae 2 2 0 0 0 3 0 0 0 0

Family Eurytomidae 1 0 0 1 0 0 0 0 0 1

Family Pteromalidae 2 2 0 1 0 2 0 0 1 0

Family Eupelmidae 1 1 0 0 0 2 0 0 0 0

Family Encyrtidae 1 1 0 1 0 1 0 0 1 0

Family Bethylidae 1 0 1 1 0 0 1 1 1 0

Family Chrysididae 1 1 0 0 4 3 0 0 0 0

Family Mutillidae 1 1 0 0 5 0 0 0 0 0

Family Sapygidae? 1 1 0 0 0 3 0 0 0 0Family Sphecidae 3 2 0 1 3 0 0 0 1 0Family Halictidae 2 2 0 0 2 2 0 0 0 0

Family Apidae 1 1 0 0 0 2 0 0 0 0

TOTAL (INSECTS ONLY) 354 221 152 106 2110 1002 7227 1059 2083 174

TOTAL (ALL ARTHROPODS) 412 259 176 123 2443 1067 11941 1676 2387 210

I

CAPTIONS TO FIGURES

Fig. 1. The location of the Elgin Experimental Farm and a generalized map of

the farm showing the three study sites and the areas within the sites which were

sampled. The insert is a representation of the positions of pitfall traps around

each selected tree in the apple orchards (see Table 1). (A = apple orchards;

B = buildings; G = garden; R= reservoir).

Fig. 2. The two principle axes of a correspondence analysis based on species

number per insect taxon at the respective study sites (A = Blattodea; B =Mantodea; C = Dermaptera; D = Orthoptera; E = Hemiptera; F =

Thysanoptera; G = Coleoptera; H = Diptera; I = Lepidoptera; J =

Hymenoptera; K = other taxa).

Fig. 3. Diversity profiles of all insect species (A), insect species with L. humile

excluded (B), and aranids (C) sampled in three sites (see text).

/

FIG. 1

CAPE PROVINCE

21"

............

" ..........

AAA

IIIIII

l AIIII

_______J L L _

2700

III AA: I

~120m~_________~ ~ ~__ I

\ A: ""',~~"_/'... /\./\./,/\./\."...... .r.IB '\\ I~13Sm~ -------T---

, I A : A : A" I I I

, I I IB ' . .L-- --'- ~__I

L-B-J

IZl UNSPRAYEDORCHARD

~ SPRAYED ORCHARD

~ FYNBOS SITE

II SAMPLlNG AREAS

PIO.2

r I

-P

SPRAYED·-0

-

eJeD

PYNBOS·f----B ---------- ---r-- -

I- UNSPRAYED

I

FIG. 3

0.9

0.8

0.7

0.6

0.5

M , ••-, --0.3 - - "",.....~ --- "",....~.... "",..""'"

~ --0.2 ....... ----

0.1 ~_-.l-_.....l__ ___l._ ___L_ __J,_ ___'~_L...__~_..l__..J..J

0.9 B

eQ 0.8

<10.7

~ 0.6"0

=• ...-4 0.5<U> 0.4.'""" -~ --• •~ 0.3 • • •~;

40.2

I0.1

C0.9

f 0.8

0.7

0.6

0.5

0.4

0.2

0.1 ~_-.l-_.....l__ ___l._ __l._ __I._ __..L_ ___'~_I...__.L..__..J..,J

-1.0~ ~.8 ~.6 ~.4 ~.2 0 0.2 0.4 0.6 0.8

FYNBOS

BetaUNSPRAYED SPRAYED

--- • • • • •