The negative effect of some selective insecticides on the functional response of a potential biological control agent,the spider <Emphasis Type="Italic">Philodromus cespitum</Emphasis>

The impact of five selective insecticides on the functional response of a potential biological control agent, the spider Philodromus cespitum (Walckenaer) (Araneae: Philodromidae), was studied in the laboratory. This spider is the most abundant beneficial arthropod on trees in commercial orchards in central Europe. We expected that selective insecticides applied at the recommended doses would have no effect or a negligible effect on the spiders’ performance. Our results showed that the mortality of spiders resulting from residual uptake of the chemicals differed among insecticides. Dimilin, NeemAzal, Mospilan, and Integro caused mortality of less than 10%, while SpinTor caused mortality of 17%. All five preparations can be considered harmless in terms of mortality in comparison with Decis, which caused 80% mortality. Exposure to residues of NeemAzal, SpinTor, and Dimilin resulted in a significantly lower predation rate than the control. The lowest predation rate was observed in spiders treated with SpinTor. These results imply that the natural pest control provided by P. cespitum spiders can be weakened by the application of SpinTor, NeemAzal, and Dimilin. On the other hand, the functional response was not significantly affected by the application of Integro and Mospilan. Therefore, these two insecticides are recommended for use in the integrated pest management (IPM) of orchards.     

Allochthonous aquatic insects increase predation and decrease herbivory in river shore food webs

Rivers produce an abundance of aquatic insects that traverse land, where they can have bottom-up effects on predators, who, in turn, can have top-down effects on terrestrial herbivores. This effect can cascade down to plants. These trophic relationships were demonstrated in a field of stinging nettles, Urtica dioica , along a river in Germany. At the shore compared to similar microhabitats 30–60 m away the abundance and biomass of: midges were highest, spiders were also highest, while herbivorous leafhoppers were lowest. At the shore, nettle plants were less damaged by herbivores and thus had less regrowth. Spiders regularly captured both aquatic midges as well as terrestrial leafhoppers and they captured more individuals of both groups at the shore than further away. Midges supported high densities of shore spiders. This was inferred from correlation of distribution and diet in the absence of other environmental gradients. Removal of spiders from experimental plots caused leafhoppers to increase at the shore, causing more plant damage. These effects were not evident at spider-removal sites away from the shore. This demonstrated that spiders depressed leafhoppers and decreased herbivory on plants only at the shore. It is concluded that aquatic insects had a bottom-up effect on spiders and that this subsidy facilitated a top-down effect that cascaded from spiders to leafhoppers to plants. Similar effects would explain the distribution of arthropods along many rivers. Allochthony connects river food webs with shore food webs, making both components essential for each other.     

Prey availability,pesticides and the abundance of orchard spider communities

In a 4 year study, in southern England, the abundance of apple orchard canopy spiders and their potential prey was manipulated using two pest management strategies based on broad spectrum (highly toxic both to spiders and pests) and selective (moderately toxic to spiders but highly toxic to pests) insecticides in the first part of the growing season. The spider community was left to develop freely afterwards. Apple orchard plots untreated by pesticides served as control.The effect of insecticides was detrimental to spider populations as the treatments coincided with the peak abundance of adults in May and early June. Within adults, the treatments were harmful to female spiders, whereas, male spiders were much less affected. As a result the proportion of males increased in all of the sampled spider families.The use of selective insecticides resulted in a higher spider abundance compared to the use of broad spectrum compounds while the highest spider abundance was found in the pesticide free trees, i.e. three significantly different spider abundance levels were produced in spring. Spider abundance began to increase unequally between the treatments afterwards and became identical in the two pesticide treated plots due to the immigration of juveniles from surrounding habitats. However, a similar equalisation of abundance was not observed between the pesticide treated plots and untreated control. Analysing the abundance pattern of potential prey in the plots of the studied orchard we concluded that the post-disturbance increase in spider abundance was regulated by prey availability.     

Molecular diagnostics reveal spiders that exploit prey vibrational signals used in sexual communication

Vibrational signalling is a widespread form of animal communication and, in the form of sexual communication, has been generally regarded as inherently short‐range and a private communication channel, free from eavesdropping by generalist predators. A combination of fieldwork and laboratory experiments was used to test the hypothesis that predators can intercept and exploit such signals. First, we developed and characterized PCR primers specific for leafhoppers of the genus Aphrodes and specifically for the species Aphrodes makarovi. Spiders were collected from sites where leafhoppers were present and screened with these primers to establish which spider species were significant predators of this species during the mating period of these leafhoppers. Analysis using PCR of the gut contents of tangle‐web spiders, Enoplognatha ovata (Theridiidae), showed that they consume leafhoppers in the field at a greater rate when signalling adults were present than when nymphs were dominant, suggesting that the spiders were using these vibrations signals to find their prey. Playback and microcosm experiments then showed that E. ovata can use the vibrational signals of male leafhoppers as a cue during foraging and, as a result, killed significantly more male than female A. makarovi. Our results show, for the first time, that arthropod predators can exploit prey vibrational communication to obtain information about prey availability and use this information to locate and capture prey. This may be a widespread mechanism for prey location, one that is likely to be a major unrecognized driver of evolution in both predators and prey.     

Suction samplers are a valuable tool to sample arthropod assemblages for conservation translocation

An important component of recent nature conservation is the ecological restoration of semi-natural grasslands. The aim of such projects is usually the restoration of typical plant communities; translocation of animals, by contrast, plays only a minor role. This is based on the assumption that a recovery of the flora will lead to recovered fauna; however, this is not always the case. Suction samplers with gauze collection bags are well suited to sample arthropods, and they may also be helpful for transferring animals. However, to date, the suitability of suction samplers as a translocation tool is unclear due to a lack of empirical data on the mortality rate of the sampled arthropod taxa. In this study, we sampled arthropods (leafhoppers, spiders, beetles, and true bugs) with a suction sampler on 21 calcareous grasslands. Immediately after sampling, animals were stored in collection bags and their mortality rate was determined. We compared storage periods (1, 2, and 3 h) and tested the suitability of a cool box to reduce mortality rates. Our study revealed that arthropod mortality was generally low (9% of all sampled individuals); however, the survival rate was affected by (1) storage time, (2) storage conditions, and (3) arthropod group. The mortality of beetles and true bugs was very low and not influenced by storage time or storage conditions. In contrast, leafhoppers and spiders had higher mortality, which increased with storage time and decreased by the use of a cool box. According to our results, suction samplers can be a valuable tool to sample arthropod assemblages for conservation translocation. In order to reduce mortality in sensitive groups such as leafhoppers and spiders, the storage process can be optimised. We thus recommend (1) using a cool box and (2) minimising the period until release of the collected arthropods at the restored site.     

Spider abundance and diversity in apple orchards under three insect pest management programmes in Washington State,U.S.A.

1 Many apple growers in Washington State, U.S.A. use mating disruption (MD) for control of codling moth, Cydia pomonella (Linnaeus). Fewer applications of synthetic, broad‐spectrum insecticides are made in MD orchards than in orchards under conventional (C) management. Spider abundance and diversity in MD, C and certified organic (O) orchards were compared. Spiders inhabiting the trees (arboreal), the understory vegetation, and the ground surface were studied. 2 Total arboreal spider density and total understory spider density were significantly higher in O orchards than in MD and C orchards. Many species occurred in both the trees and the understory. 3 Arboreal, visually orientated, hunting spiders and arboreal ambushers/runners were significantly more abundant in O orchards compared to C and MD orchards. Visual hunters were significantly more abundant in MD compared to C orchards. Numbers of spiders in two other guilds (web‐makers and nocturnal hunters) showed no statistical differences with respect to orchard management type. 4 The highest density of ground surface‐dwelling spiders occurred in one of the O orchards. Two C orchards had higher densities than any MD orchard. Ground surface species were distinct from those in the understory and the trees. 5 With one exception, an orchard's arboreal fauna was most similar to that of another orchard under the same type of pest management. Three exceptions were noted among comparisons of the understory faunas. The ground surface‐dwelling fauna of one O orchard was distinctive, whereas that in the second O orchard was similar to the C and MD orchards. 6 Reduced use of synthetic, broad‐spectrum insecticides in MD orchards did not result in arboreal spider densities comparable to those found in O orchards. A contributing factor may be that all species were univoltine. Spider populations may thus be severely reduced by even a small number of synthetic, broad‐spectrum insecticide applications and the time required for recovery may be lengthy.     

The response of invertebrate assemblies to grazing

Invertebrate communities were monitored in a controlled sheep grazing experiment on ex-arable land on limestone and in nearby older calcicolous grasslands Results for vacuum sampling of Heteroptera and herbivorous Coleoptera are presented and compared with the responses of spiders, leafhoppers and leaf-miners
Invertebrate groups differed in their responses to grazing and grassland age in terms of species diversity, abundance, variability over time and the development of a specific fauna on short turf Leaf-miner assemblies were most strongly determined by the effects of grazing on plant species composition, while spiders' responses could largely be explained by the effects of grazing on plant architecture Spider species simply accumulated over time, whilst leaf-miners were the most labile group Spiders, leaf-miners and leafhoppers all contained some common species restricted to old grasslands, whilst herbivorous Coleoptera and Heteroptera did not
No single group demonstrated the full range of invertebrate responses Spiders, leafhoppers and leaf-miners each showed useful features as "indicator groups'", but more than one group should be chosen for study in the context of particular research projects     

Organic Farming: Biodiversity Impacts Can Depend on Dispersal Characteristics and Landscape Context

Organic farming, a low intensity system, may offer benefits for a range of taxa, but what affects the extent of those benefits is imperfectly understood. We explored the effects of organic farming and landscape on the activity density and species density of spiders and carabid beetles, using a large sample of paired organic and conventional farms in the UK. Spider activity density and species density were influenced by both farming system and surrounding landscape. Hunting spiders, which tend to have lower dispersal capabilities, had higher activity density, and more species were captured, on organic compared to conventional farms. There was also evidence for an interaction, as the farming system effect was particularly marked in the cropped area before harvest and was more pronounced in complex landscapes (those with little arable land). There was no evidence for any effect of farming system or landscape on web-building spiders (which include the linyphiids, many of which have high dispersal capabilities). For carabid beetles, the farming system effects were inconsistent. Before harvest, higher activity densities were observed in the crops on organic farms compared with conventional farms. After harvest, no difference was detected in the cropped area, but more carabids were captured on conventional compared to organic boundaries. Carabids were more species-dense in complex landscapes, and farming system did not affect this. There was little evidence that non-cropped habitat differences explained the farming system effects for either spiders or carabid beetles. For spiders, the farming system effects in the cropped area were probably largely attributable to differences in crop management; reduced inputs of pesticides (herbicides and insecticides) and fertilisers are possible influences, and there was some evidence for an effect of non-crop plant species richness on hunting spider activity density. The benefits of organic farming may be greatest for taxa with lower dispersal abilities generally. The evidence for interactions among landscape and farming system in their effects on spiders highlights the importance of developing strategies for managing farmland at the landscape-scale for most effective conservation of biodiversity.     

Computer simulation of genetic control. Comparison of sterile males and field-female killing systems

Summary A computer program, GENCON, designed to simulate genetic control using field-female killing systems, is described. These systems incorporate sex-linked translocations and conditional lethal mutations. Genetic death in field populations is caused by semisterility of the translocation and by homozygosis of the mutations in females and non-translocation males of field origin. Simulations using the program compare the effectiveness, in populations regulated by density, of genetic control using this type of system with control using sterile-male release. At high release rates, sterile males cause more rapid suppression and earlier eradication than sex-linked translocation strains. However, if releases are interrupted before eradication, the rate of recovery of density-dependent populations is more rapid following sterile-male release than following suppression with translocation strains. In such populations, the cumulative population suppression (number of individuals killed) is greater with translocation-strain release than with sterile-male release. At low release rates, sex-linked translocation strains can be much more effective at suppressing and eradicating density-dependent populations than sterile males. In continental Australia, eradication of the sheep blowfly Lucilia cuprina is probably not practicable. A suppression campaign using sex-linked translocation strains could yield a higher benefit to cost ratio than one using sterile males.     

化学杀虫剂对菜田节肢动物多样性的影响

分析了化学杀虫剂对菜田节肢动物结构组成、多样性变化等的影响,结果表明化学杀虫剂对菜田节肢动物的影响主要表现在物种组成、多样性指数及物种分布的均匀性等方面,尤其是对害虫类、捕食性天敌和蜘蛛类的影响尤为明显。停止化学杀虫剂使用后,菜田优势害虫种群趋势指数降低,天敌的控制作用明显增强,节肢动物多样性指数增大。因此,限制和停止化学杀虫剂的使用,恢复由于杀虫剂使用而破坏了的菜田环境,逐步增强天敌对优势害虫的控制能力,这在菜田害虫生态控制中具有重要作用。     

Stimulus discrimination and wave source localization in fishing spiders (Dolomedes triton and D. okefinokensis)

We have studied the behavioral responses of fishing spiders (Dolomedes triton and Dolomedes okefinokensis) to water surface wave stimuli. D.okefinokensis responded to click-like wave stimuli (Fig. 3C) in less than 15% of the cases. Responsiveness did not increase if up to 20 clicks were elicited in quick succession from the same spot (Fig. 5). If longer lasting concentric stimuli were offered, the spiders determined the direction (Fig. 6) and the distance (Fig. 8) to the wave source. This was true for monofrequency stimuli and for narrow-band and broadband noise stimuli. If concentric multifrequency surface waves were offered, even a fivefold decrease in stimulus amplitude did not significantly change the mean running distance of D.triton. However, if multifrequency wave stimuli with a flat wave front were presented, the spiders (D.triton) no longer determined the source distance precisely (Figs. 11, 12). Our results indicate that fishing spiders of the genus Dolomedes mainly use the curvature of a concentric wave stimulus for distance determination.     

Recombinant viral insecticides: Delivery of environmentally safe and cost-effective products

Biological control agents such as baculovirus insecticides have many attributes which make them attractive alternatives to synthetic chemical pesticides. However, there have been several economic and agronomic barriers to their widespread use. Among the obstacles to commercialization of viral insecticides have been high production costs, the lack of efficacious formulation and application technologies, and a slow speed of action. Biotechnology has contributed several advances toward overcoming these obstacles. The high cost ofin vivo production can be reduced significantly using a newly developed high-density rearing system termed HeRD. The HeRD technology can be used to rear many different species of lepidopterous larvae for production of viral insecticides, as hosts for parasitoid production, or for sterile-male release programs. Using this technology, the baculovirus production costs are equivalent to sprayable Bt toxins. The field efficacy of viral pesticides and other biological control agents requires cost effective, biologically based formulation and application technologies. Based on current field efficacy evaluations of baculovirus pesticides, formulation/application technologies must be improved for viral pesticides to compete effectively and consistently in most pesticide markets. Through recombinant DNA technology, it is now possible to insert foreign pesticidal genes into viral pesticides, resulting in faster time to death or, more importantly, time to cessation of feeding of the target pests. However, the commercial use of recombinant pesticides has raised several potential environmental issues, including possible effects on non-target organisms, ecological interactions, mitigation and genetic stability. Genetic strategies have been developed to mitigate most of the potential problems associated with recombinant baculovirus pesticides. Five field tests have been conducted in the U.S. to evaluate these strategies. The laboratory and field results illustrate that the genetic strategies employed ensure environmental safety while also reducing production costs.     

Monitoring of wheat insects and their natural enemies using sticky traps in wheat

Beneficial arthropods and wheat insects were monitored using sticky traps through large-scale field in Saxony, Germany before and after insecticide applications. The tested compounds (Karate, Biscaya and NeemAzal T/S) were sprayed twice at Elongation stage (GS 32) and at the heading stage (GS 55). Monitoring was conducted for four weeks after each treatment. Cereal aphids, thrips, leafhoppers, cereal leaf beetles, cereal bugs and also many natural enemies such as predators (lady beetles, lacewings, syrphids, dance flies and spiders) and parasitoids (parasitic wasps) were surveyed. The results proved that Karate caused the highest per cent mortality to wheat insect pests. Karate also reduced natural enemy diversities. Biscaya and NeemAzal T/S is correlated with an equivalent mortality per cents to wheat insect pests and resulted in a smaller effects on natural enemies compared with Karate. Leafhoppers were less affected than Thrips and cereal bugs. Parasitoid wasps and spider were more tolerant, while lacewings and dance flies were more susceptible to insecticide effects. Finally, natural insecticides and predators and parasitoids could be highly compatible with a hygienic environment.     

Side-effects of insecticides on two erigonid spider species

The current rearing technique forErigone atra (Blackwall) andOedothorax apicatus (Blackwall) (Araneae, Erigonidae) was improved. To reduce time spent rearing on live fruit flies the spiders were kept on a culture of the Collembola speciesLepidocyrtus lanuginosus (Gmelin) (Entomobryidae). Side-effects on spiders of two pyrethroid insecticides (fenvalerate and lambda-cyhalothrin) and one carbamate insecticide (pirimicarb) were tested. Sensitivity of adults of both sexes and juveniles to insecticides and their influence on the rate of emergence of spiderlings from cocoons were investigated using topical application, spraying or residual contact. LD₅₀ values for adults ranged from 0.49 to 2.52 ng a.i./spider for lambda-cyhalothrin and from 5.75 to 98.20 ng a.i./spider for fenvalerate. Topical application also resulted in up to a week's delay of web-building. A moving laboratory spraying equipment was used to spray spiders with different insecticide dosages and water volumes. Pyrethroids sprayed onto adults in webs had stronger effects than pyrethroids sprayed onto sitting or walking spiders on the soil surface. Residual contamination caused higher mortality of spiders after contact with lambda-cyhalothrin than fenvalerate. In all tests, males were more susceptible to pyrethroids than females; this difference was related to body weight. Mortality rate was higher forE. atra than forO. apicatus. Both pyrethroids were also toxic to spiderlings. Lambda-cyhalothrin inhibited emergence ofE. atra spiderlings from cocoons. Pirimicarb was harmless to both spider species.     

Herbivore release through cascading risk effects

Predators influence prey through consumption, and through trait-mediated effects such as emigration in response to predation risk (risk effects). We studied top-down effects of (sub-) adult wolf spiders (Lycosidae) on arthropods in a meadow. We compared risk effects with the overall top-down effect (including consumption) by gluing the chelicers of wolf spiders to prevent them from killing the prey. In a field experiment, we created three treatments that included either: (i) intact (‘predation’) wolf spiders; (ii) wolf spiders with glued chelicers (‘risk spiders’); or (iii) no (sub-) adult wolf spiders. Young wolf spiders were reduced by their (sub-) adult congeners. Densities of sheetweb spiders (Linyphiidae), a known intraguild prey of wolf spiders, were equally reduced by the presence of risk and predation wolf spiders. Plant- and leafhoppers (Auchenorrhyncha) showed the inverse pattern of higher densities in the presence of both risk and predation wolf spiders. We conclude that (sub-) adult wolf spiders acted as top predators, which reduced densities of intermediate predators and thereby enhanced herbivores. Complementary to earlier studies that found trait-mediated herbivore suppression, our results demonstrate that herbivores can be enhanced through cascading risk effects by top predators.     

Transgenic Bt potato and conventional insecticides for Colorado potato beetle management: comparative efficacy and non-target impacts

Field studies were conducted in 1992 and 1993 in Hermiston, Oregon, to evaluate the efficacy of transgenic Bt potato (Newleaf^®, which expresses the insecticidal protein Cry3Aa) and conventional insecticide spray programs against the important potato pest, Leptinotarsa decemlineata (Say), Colorado potato beetle (CPB), and their relative impact on non-target arthropods in potato ecosystems. Results from the two years of field trials demonstrated that Newleaf potato plants were highly effective in suppressing populations of CPB, and provided better CPB control than weekly sprays of a microbial Bt-based formulation containing Cry3Aa, bi-weekly applications of permethrin, or early- and mid-season applications of systemic insecticides (phorate and disulfoton). When compared with conventional potato plants not treated with any insecticides, the effective control of CPB by Newleaf potato plants or weekly sprays of a Bt-based formulation did not significantly impact the abundance of beneficial predators or secondary potato pests. In contrast to Newleaf potato plants or microbial Bt formulations, however, bi-weekly applications of permethrin significantly reduced the abundance of several major generalist predators such as spiders (Araneae), big-eyed bugs (Geocorus sp.), damsel bugs (Nabid sp.), and minute pirate bugs (Orius sp.), and resulted in significant increases in the abundance of green peach aphid (GPA), Myzus persicae (Sulzer) – vector of viral diseases, on the treated potato plots. While systemic insecticides appeared to have reduced the abundance of some plant sap-feeding insects such as GPA, lygus bugs, and leafhoppers, early and mid-season applications of these insecticides had no significant impact on populations of the major beneficial predators. Thus, transgenic Bt potato, Bt-based microbial formulations and systemic insecticides appeared to be compatible with the development of integrated pest management (IPM) against other potato pests such as GPA because these CPB control measures have little impact on major natural enemies. In contrast, the broad-spectrum pyrethroid insecticide (permethrin) is less compatible with IPM programs against GPA and the potato leafroll viral disease.     

Botanicals,selective insecticides,and predators to control Diaphorina citri （Hemiptera： Liviidae） in citrus orchards

The Asian citrus psyllid （ACP） Diaphorina citri Kuwayama vectors pathogens that cause huanglongbing （HLB） or citrus greening devastating and economically im- portant disease present in most citrus growing regions. Young citrus shoots are required for psyllid reproduction and development. During winter citrus trees produce little or no new growth. Overwintering adults reproduce in spring on newly emerging shoots also attractive to other pests and beneficial insects. Botanicals and relatively selective insecti- cides could help to conserve beneficial insects and reduce pest resistance to insecticides. Sprays of Azadirachtin （Neem）, Tropane （Datura）, Spirotetramat, Spinetoram, and broad- spectrum Imidacloprid were evaluated to control ACP in spring and summer on 10-year-old ＂Kinow＂ Citrus reticulata Blanco trees producing new growth. Psyllid populations were high averaging 5-9 nymphs or adults per sample before treatment application. Nymphs or adults were significantly reduced to 0.5-1.5 per sample in all treatments for 3 weeks, aver- age 61%-83% reduction. No significant reduction in ladybeetles Adalia bipunctata, Ane- glei scardoni, Cheilomenes sexmaculata, and Coccinella septempunctata was observed. Syrphids, spiders and green lacewings were reduced in treated trees except with Tropane. Studies are warranted to assess impact of these predators on ACP and interaction with insecticides. Observed reduction in ACP populations may not be enough considering its reproductive potential and role in the spread of HLB. Follow-up sprays may be required to achieve additional suppression using rotations of different insecticides.     

Insecticides suppress natural enemies and increase pest damage in cabbage

Intensive use of pesticides is common and increasing despite a growing and historically well documented awareness of the costs and hazards. The benefits from pesticides of increased yields from sufficient pest control may be outweighed by developed resistance in pests and killing of beneficial natural enemies. Other negative effects are human health problems and lower prices because of consumers' desire to buy organic products. Few studies have examined these trade-offs in the field. Here, we demonstrate that Nicaraguan cabbage (Brassica spp.) farmers may suffer economically by using insecticides as they get more damage by the main pest diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), at the same time as they spend economic resources on insecticides. Replicated similarly sized cabbage fields cultivated in a standardized manner were either treated with insecticides according common practice or not treated with insecticides over two seasons. Fields treated with insecticides suffered, compared with nontreated fields, equal or, at least in some periods of the seasons, higher diamondback moth pest attacks. These fields also had increased leaf damage on the harvested cabbage heads. Weight and size of the heads were not affected. The farmers received the same price on the local market irrespective of insecticide use. Rates of parasitized diamondback moth were consistently lower in the treated fields. Negative effects of using insecticides against diamondback moth were found for the density of parasitoids and generalist predatory wasps, and tended to affect spiders negatively. The observed increased leaf damages in insecticide-treated fields may be a combined consequence of insecticide resistance in the pest, and of lower predation and parasitization rates from naturally occurring predators that are suppressed by the insecticide applications. The results indicate biological control as a viable and economic alternative pest management strategy, something that may be particularly relevant for the production of cash crops in tropical countries where insecticide use is heavy and possibly increasing.     

Effectiveness and pesticide susceptibility of the pyrethroid-resistant predatory mite Amblyseius womersleyi in the integrated pest management of tea pests

To prevent the resurgence of the Kanzawa spider mite, Tetranychus kanzawai Kishida, on tea plants caused by the application of synthetic pyrethroid insecticides (SP), an SP-resistant strain of the predatory mite Amblyseius womersleyi Schicha was released onto tea bushes under SP (permethrin) application. The released predators successfully survived and may be able to suppress T. kanzawai. In the plot where A. womersleyi was released, the damage to new leaves was less severe than in the control plot and the predators remained resistant to the permethrin in the bushes. The selective use of pesticides that are harmless against natural enemies is necessary to achieve a program of integrated tea pest management. Although mortality of adult females of the tested strain in response to SP was from 6.5 to 89.3%, and mortality was more than 95% in response to several carbamate and organophosphate insecticides, usefulness of A. womersleyi as an agent of biological control was successfully demonstrated in the present study.