Potato/Maize intercropping reduces infestation of potato tuber moth, Phthorimaea operculella(Zeller) by the enhancement of natural enemies

The potato tuber moth(PTM),Phthorimaea operculella(Zeller),is one of the most economically significant insect pests for potato in both field and storage worldwide.To evaluate the infestation,reduction of potato yield and the control efficacy for PTM,field tests were conducted in two seasons by intercropping of potato as the host plant with maize as a non-host plant of PTM.Three intercropping patterns were tested,which were 2 rows of potatoes with either 2,3,or 4 rows of maize(abbreviated 2 P:2 M,2 P:3 M,and 2 P:4 M),and the monocropped potato as the control,2 rows of potatoes,without maize,(abbreviated 2 P:0 M).Results showed that the population and infestation of PTM in the 2 P:3 M intercropping pattern was significantly lower than those in 2 P:2 M,2 P:4 M and the monocropping pattern of 2 P:0 M,due to the enhancement of natural enemies.Cumulative mines and tunneling in potato leaves in 2 P:3 M intercropping were significantly lower than those in 2 P:2 M and 2 P:4 M patterns.The population of parasitoids and the parasitism rate of PTM in intercropping pattern of 2 P:3 M were significantly higher than that in intercropping pattern of 2 P:2 M,2 P:4 M and monocropping pattern of 2 P:0 M.We conclude that the potato intercropped with maize reduced the adult and larva populations,and reduced the damage from PTM by enhancing the number of parasitoids and the level of parasitism.The greatest population density of parasitoids and parasitism rate were in the intercropping pattern of 2 rows of potatoes with 3 rows of maize.These data indicate that the host/non-host intercropping patterns can be used as a biological control tactic against PTM by enhancing the density of natural enemies in the agro-ecosystems.

Dominant Natural Enemies of Sugarcane Pests and Their Protection and Utilization in Yunnan

This paper discussed and summarized the parasitic characters and the protection and utilization of 7 species of dominant natural enemies of sugarcane pests in Yunnan, China. Sugarcane pests are numerous and there are rich natural enemy resources in Yunnan sugarcane areas. There are more than 283 species of natural enemies against sugarcane pests in Yunnan, among which the dominant natural enemies with protection and utilization value and research significance include Trichogramma, Apanteles flavipes(Cameron) and Sturmiopsis inferens Townsend parasitic on sugarcane borers, Synonycha grandis(Thunberg), Lemnia biplagiata(Swartz), Chilomenes sexmaculata(Fabricius) and Thiallela sp catching and feeding on Ceratovacuna lanigera Zehntner, and Euborellia pallipes Shiraki preying on Saccharicocus sacchari(Cocherell), Dysmicoccus bohinsis Kuw, Trochorhopalus humeralis Chevrolat and Diocalandra sp. There is also one fungal parasite, namely Beauveria bassiana, which is widely distributed in nature, and can parasitize in a variety of sugarcane pests including sugarcane borers, Exolontha serrulata(Gyllenhal), Alissonotum impressicolle Arrow, T. humeralis and Otidognathus rubriceps Chevrola. It has a natural parasitism rate generally around 10% and certain natural inhibition effect on sugarcane pests. Reasonably protecting and utilizing natural enemies and giving full play to the natural regulation of natural enemies on pests are of great significance for protecting the ecological environment, maintaining the ecological balance of sugarcane fields, improving the comprehensive management level of pests, and promoting the sustainable development of sugar industry.

Impact Analysis of Genetically Modified (Bt) Cotton Genotypes on Economically Important Natural Enemies under Field Conditions

Field studies were conducted at Hisar during Kharif, 2009-2010 and 2010-2011 under natural and unsprayed condition. RCH 134 Bt, HS 6 (non Bt), H 1117 and Ganganagar Ageti (non Bt) were selected for the studies. The experiment was laid down in Randomized Block Design replicated thrice having plant spacing 67.5 × 60 cm. Among the bollworms, Erias spp. exhibited positive correlation with rainfall, minimum temperature and relative humidity morning hours significantly at 5 percent level whereas Helicoverpa and Pectinophora displayed positive relations only with evening hours relative humidity significantly while Spodoptera were significantly positive correlated with relative humidity of morning and evening hours. Bollworm complex was negatively correlated with all the weather parameters employed to study although being non-significant in case of rainfall, maximum and minimum of temperature, morning and evening hours of relative humidity. Among the sucking pests, leafhoppers, whitefly, thrips and aphids population showed significantly negative correlation with weather parameters. The comparison of natural bio-agents in cotton hybrids under study revealed that overall mean population of natural enemies were higher in Bt cotton hybrid as compared to non-Bt. These results confirm that use of genetically modified (Bt) cotton in lieu of conventional genotypes could positively impact non-target and beneficial insect species by preserving their host populations.

Natural Enemies of Calidea panaethiopica (Heteroptera: Scutelleridae): An Insect Pest of Jatropha curcas L. in the South-Sudanian Zone of Burkina Faso

Jatropha curcas L. is a non-edible oleaginous plant of Euphorbiacea family. Its seeds provide oil for industrial use, and when grown as a biofuel, J. curcas can be used to restore degraded soil by improving their fertility and by controlling water and wind erosion. The plant also reduces CO2 emission by carbon sequestration. However, J. curcas is attacked by many insect pests including C. panaethiopica, a polyphagous heteroptera of the Scutelleridae family. Larvae and adults of the insect pest feed on J. curcas flowers, fruit, and seeds, thereby causing quantitative and qualitative losses. Despite the economic importance of this insect pest, there is little known about its potential natural enemies. A survey of the natural enemies of C. panaethiopica was carried out from 3rd June 2013 to 29th May 2014 on three J. curcas production sites in the South-Sudanian zone of Burkina Faso. Three Hymenopteran egg parasitoids all belonging to the Scelionidae family were found. These included Trissolcus basalis (Wollaston), Psixstriaticeps (Dodd), and Gryon sp. Several predator species belonging to the Araneae, Tarachodidae and Mantidae families were also found. The egg parasitism increased progressively between June and September 2013, reaching a peak (43%) in September 2013. The number of spiders and mantises was higher between July and August 2013. The highest numbers of natural enemies associated with the insect pest were recorded in J. curcas monoculture plantations.

Effects of Some Materials Extracted from Ajuga Species on the Larvae of Hyphantria cunea and its Natural Enemies

Six kinds of cxtracts drawn from Ajuga multiflora and .A. multliflora var. brevispicala and A. multiflora var.serotina using methanol and acetone were used in this experiment to test their killing activity to the second instar larvae ofHypantria cunea and their influence on its natural enemics. The average death rate caused by those extracts on the secondinstar larvae was 85.70%. The mortality rate caused by the extracts drawn with methanol was from 88.89% to 96.33%,which was significal1tly l1igl1er tl1a11 tl1at caused by acetol1e extracts. 'I11osc extracts were satt to TrchogranInIa `Ie)uI,xiIinIi,Coccinella septempunctata, the natural enelnies of H. cunea. We did not found any evidence shown that those extracts hadany influence the emergence and the devclopment of T. dendrolimi. Those methanolic extracts gotten from A. multiflora andA. multiflora var. brevispicata had no significant effects on the mortality of the larvae and adults of C. septenrpunctala.Those eXtracts could be used in the control of H cunea sattly.

Host plants and natural enemies of Bemisia tabaci （Hemiptera： Aleyrodidae）in China

The sweetpotato whitefly, Bemisia tabaci, has been a destructive pest in China for over the past two decades. It is an extremely polyphagous insect, being recorded feeding on hundreds of host plants around the world. Potential host plants and natural enemies of B. tabaci in the south, southeast, middle, north and northwest of China were investigated during the last decade. In total 361 plant species from 89 families were recorded in our surveys. Plants in the families Compositae, Cruciferae, Cucurbitaceae, Solanaceae and Leguminosae were the preferred host species for B. tabaci, which therefore suffered much damage from this devastating pest due to their high populations. In total, 56 species of parasitoids, 54 species of arthropod predators and seven species of entomopathogenic fungi were recorded in our surveys. Aphelinid parasitoids from Encarsia and Eretrnocerus genera, lady beetles and lacewings in Coleoptera and Neuroptera were found to be the dominant arthropod predators of B. tabaci in China. The varieties of host plant, their distribution and the dominant species of natural enemies of B. tabaci in different regions of China are discussed.

New Evidence for the Hypothesis of Reducing Natural Enemy Pressure of Eupatorium adenophorum: Solenopsis invicta Competing with Doxrylus orientalis to Feed on E. adenophorum

Natural enemy insects are important factors in regulating plant invasion. The interactions between multiple insect species resulting from invasive plants remain poorly understood despite their potential. We observed notorious invasive plants Eupatorium adenophorum Sprengel were competedly fed by Solenopsis invicta Buren (Hymenoptera: Formicidae) and Dorylus orientalis Westwood (Hymenoptera: Formicidae) beside the scientific research base of Kunming University. It was first observed that D. orientalis was eating the epidermis, cortex, phloem and other root and stem tissues of E. adenophorum in soil. Two months later, it was observed that S. invicta ate the epidermis, cortex, phloem and other aboveground stem tissues of E. adenophorum. S. invicta attacked D. orientalis and displaced their living space by causing the later dead, injured, or even disabled. This phenomenon suggested that local herbivorous insects have adapted to E. adenophorum well, which will intensify the naturalization process of E. adenophorum in local habitats. In a homogeneous garden planting experiment of E. adenophorum conducted at the experimental base of Kunming University, the biomass of the introduced (China) populations of E. adenophorum was lower than that of the native (Mexico) populations, although there was no statistically significant difference. These results indicate a possible positive correlation between the increase in natural enemy pressure and the decrease in fitness of E. adenophorum.

Influence of Garlic Intercropping or Active Emitted Volatiles in Releasers on Aphid and Related Beneficial in Wheat Fields in China

In order to develop biological control of aphids by a ＂push-pull＂ approach, intercropping using repellent emitting plants was developed in different crop and associated plant models. Garlic is one of the potential plant that could be inserted in crops to decrease the pest occurrence in neighboring crop plots. In this study, field works were conducted in wheat fields in Langfang Experimental Station, Hebei Province in China from October 2009 to July 2010 during wheat developmental season. The effect of wheat intercropping with garlic but also the volatiles emission on the incidence of the English grain aphid, Sitobion avenae Fabricius （Homoptera： Aphididae） was assessed. Natural beneficial occurrence and global yields in two winter wheat varieties that were susceptible or resistant to cereal aphid were also determined comparing to control plots without the use of garlic plant intercrop nor semiochemical releaser in the fields. S. avenae was found to be lower in garlic oil blend treatment （GOB）, diallyl disulfide treatment （DD） and wheat-garlic intercropping treatment （WGI） when compared to the control plots for both two varieties （P〈0.01）. Both intercropping and application of volatile chemicals emitted by garlic could improve the population densities of natural enemies of cereal aphid, including ladybeetles and mummified aphids. Ladybeetle population density in WGI, GOB and mummified aphids densities in WGI, DD were significantly higher than those in control fields for both two varieties （P〈0.05）. There were significant interactions between cultivars and treatments to the population densities of S. avenae. The 1 000-grain weight and yield of wheat were also increased compared to the control. Due to their potential alternatives as a biological control agent against cereal aphid, garlic intercropping and related emitted volatiles are expected to contribute to the further improvement of integrated pest management systems and to potentially reduce the amount of traditional synthetic pesticides applied in wheat fields.

Effects of sesame nectar on longevity and fecundity of seven Lepidoptera and survival of four parasitoid species commonly found in agricultural ecosystems

Ecological engineering involves the use of plants to promote establishment, survival and efficiency of natural enemies in agricultural systems. Some plant species may be hosts or provide resources to some pest species. We assessed the risks and benefits of sesame （Sesamum indicum L.）, as a nectar source for seven economically important Lepidopteran pest and four parasitoid species in a range of vegetable crop systems. Our results showed that the mean Iongevities of arthropod parasitoids Pteromalus puparum （L.）, Encarsia sophia （Girault ＆ Dodd） and male Microplitis tuberculifer （Wesmael） were significantly extended when fed on sesame flowers compared to the water control. Sesame flowers had no effect on adult Iongevities and fecundities of six out of the seven Lepidoptera pest species tested except Plutella xyllostella （L.） females laid more eggs when fed on sesame flowers. It is likely that the increased fecundity is due to accessibility to nectar at the bottom of corolla because of their smaller body sizes. Our findings provide a first step towards better understanding of the risks and benefits of using sesame to implement ecological engineering for the management of vegetable pests.

Survey of Occurrence and Damage of Xylotrechus quadripes Chevr on Simao Coffee in Pu＇er City

The occurrence and damage of Xylotrechus quadripes Chew were investigated in different time points and micro environments in Siman south island river coffee test demonstration field. The results showed that X. quadr/pes mainly damaged 5-year-old coffee trees. X. quadr/pes occurred one generation per year in Siman region, and the larval stage lasted 296 - 322 d. The adult could be found in four seasons because of different development progress and overlapping generations. In different micro environments, X. quadr/pes were mainly distributed in mixed forests and the coffee land in sunny slope. The adult enjoyed sunshine on the coffee trees at noon. The nattwal enemy Prislauacus nigripea kieff was found to parasitize in the larvae of X. quadripes, which could control the population of X. quadr/pes.

The Potential of Common Beneficial Insects and Strategies for Maintaining Them in Bean Fields of Sub Saharan Africa

Beneficial insects provide natural ecosystem services such as biological control of pests, soil formation, nutrient cycling and pollination of plants. Beneficial insects include pollinators important in the essential pollination process of all plants, and natural enemies of pests such as parasitoids and predators which are important in the suppression of pest damage to crops. Knowledge on management techniques to attract beneficial insects in the agricultural fields is a way forward to enhance agro ecosystems for increased crop production. Therefore, proper understanding and identification of natural enemies, as well as pollinators in agricultural fields, is essential in promoting biological control and pollination activity. Natural enemies and pollinators, within legume fields, play a key role in ensuring sustainable production, especially in smallholder farms. There is a limited understanding of beneficial insects and the ecosystem services they offer to the agricultural production process in much of sub-Saharan Africa. This paper reviewed and provided existing knowledge on beneficial insects in bean fields. This will give the basis for research on beneficial insects in bean fields and practices that encourage their populations.

Interactions between Entomopathogenic Fungi and Entomophagous Insects

Direct treatment of predators with entomopathogenic fungi (EPF) at different concentrations revealed that some species, like Beauveria bassiana and Metarhizium anisopliae, were found to have detrimental effects on all developmental stages of some predator species. Other species, like Numoraea rileyi and Paecilomycis fumosorosius, showed little or no effect on treated predators. Adult predators were found to avoid feeding on fungi-infected prey. EPF could be isolated from hibernating or field-collected coccinellids. Some studies indicated that combining a fungus with a predator could increase the rate of insect control in the field. As for parasitoids, this review indicates that the developmental stages of the egg parasitoids can develop successfully in host eggs treated with fungi. However, fungus-infected hosts negatively impact the development of larval parasitoids inside such hosts and this impact depends on the species and concentration of the fungus as well as the time between infection and parasitism. Some parasitoid females can discriminate between fungus-infected and uninfected hosts and do not parasitize the infected hosts. With appropriate timing, the parasitoids or predators could be combined with fungi for the biological control of insects in the field.

The Predatory Function of Three Spiders to Two Insect Pests in Rice Within a Multi-species Co-existence System

The prey-seeking behavior of three spiders (X1-Pirata subpiraticus, X2-Clubiona japonicola and X3-Tetragnatha japonica) for brown plant hopper (X4-Nilaparvata lugens) and rice spittle bug (X5-Cal-litettix versicolor) was investigated, as well as how interference between and within species occurred, by using a quadratic regression rotational composite design. Six predation models derived from the analysis of interactions among and within predators and preys were developed. The total predatory capacity of spiders on rice insect pests after coexistence for one day can be expressed as follows: Y3 = 32.795 + 2.25X1 + 1.083X2 + 0.5X3 + 10.167X4 + 3.167X5 - 1.67X12 - 2.42X22 - 3.295X32 - 0.045X42 + 0.455X52 - 3.125X1X2 + 0.375X1X3 -0.625X1X4 - 0.375X1X5 + 0.375X2X3 - 0.875X2X4 + 0.125X2X5 + 0.375X3X4 - 0.375X3X5 + 0.125X4X5. The principal efficiency analysis using this model indicated that increases in insect pest density significantly increased predation by predators; this was much greater than the effect of any single predator. X4 had a greater effect than X5; however, X4 and X5 demonstrated little interspecific interference and even promoted each other and increased predation rates as the densities of the two pests increased. Among the three predators, an increase in the density of X, had the greatest effect on the increase in predation, X3 had the second, X2 the third greatest effect. As predator density increased inter- and intra-species interference occurred, which were largely related to the size, activity, niche breadth, niche overlap and searching efficiency of the predators. X2 produced the greatest interference between different individuals and between any other predator species. X3 had the second greatest, which reduced predation levels at high predator densities. Because of these factors, the highest predation rate was obtained at a prey density of 120 per 4 rice-hills. The optimal proportion of the three predators in the multi-predator prey system was X1: X2: X3 = 5.6:1.3:4.1.

Deterministic and Stochastic Fractional Order Model for Lesser Date Moth

In this paper,a deterministic and stochastic fractional order model for lesser date moth(LDM)using mating disruption and natural enemies is proposed and analysed.The interaction between LDM larvae,fertilized LDM female,unfertilized LDM female,LDM male and the natural enemy is investigated.In order to clarify the characteristics of the proposed deterministic fractional order model,the analysis of existence,uniqueness,non-negativity and boundedness of the solutions of the proposed fractional-order model are examined.In addition,some sufficient conditions are obtained to ensure the local and global stability of equilibrium points.The occurrence of local bifurcation near the equilibrium points is investigated with the help of Sotomayor’s theorem.Numerical simulations are conducted to illustrate the properties of the proposed fractional order model with respect to the intrinsic growth rate of the LDM larvae,natural enemy’s mortality rate,predation rate,sex pheromone trap parameter,fractional order and environmental noise.The impact of mating disruption on lesser date moth is demonstrated.Also,a numerical approximation method is developed for the proposed stochastic fractional-order model.

Including predator presence in a refined model for assessing resistance of alfalfa cultivar to aphids

The aphid quantity ratio（AQR） is defined as the number of aphids on each cultivar divided by the number of aphids on all cultivars. AQR is based on the correlation between aphid populations and their host plants and is an important tool that has been utilized in evaluating Medicago sativa（alfalfa） cultivar resistance to aphids. However, assessment of alfalfa resistance to aphids can be confused by the presence of aphid predators, causing the assessment of plant resistance to aphids to be based on incorrect aphid population data. To refine the AQR and account for the effect of predators on aphid population assessments, we introduced a parameter ‘α＇, corresponding to the predator quantity ratio, and used αAQR as the ratio to quantify aphid populations. Populations of both aphids（4 species） and their predators（12 species） occurring in 28 M. sativa cultivars were sampled over two years at a research station near Cangzhou, Hebei Province, China. Results showed that the most suitable evaluation period was from May to June, as the aphid population was stable during this period. Compared with the AQR method, the predator population numbers based on the αAQR had a significant inverse relationship with aphid population numbers and the 28 cultivars were clustered into three classes： the resistant class, tolerant class, and susceptible class. In addition, 17 cultivars were reassigned when evaluated using αAQR. All numerical values calculated by αAQR were displayed as a Gaussian distribution, which showed that the 28 cultivars could be clustered into nine groups using a median value（±SE） of 1±0.1. Hence, ongoing alfalfa breeding trials will be assessed using the αAQR to establish a robust system that includes agronomic performance parameters in order to generalize the new method for further studies.

Functional and numerical responses of Cyrtorhinus lividipennis to eggs of Nilaparvata lugens are not affected by genetically modified herbicide-tolerant rice

To safely and sustainably utilize genetic breeding techniques for crop production, greater understanding of the potential effects of genetically modified herbicide-tolerant（GMHT） crops on the ecological functions of predators is required. In the laboratory, we examined the functional and numerical responses of Cyrtorhinus lividipennis Reuter to eggs of brown planthopper（BPH）, Nilaparvata lugens（St？l）, which were reared on GMHT rice Bar68-1; the untransformed parental cultivar, D68; or a BPH-susceptive rice variety, Taichung Native 1. All stages of nymphs and female adult of C. lividipennis, either on GMHT rice or control plants, exhibited typical type II functional responses when fed on BPH eggs; the attacking rate and handling time of C. lividipennis on GMHT rice Bar68-1 was not significantly different from that on D68. The numerical responses of C. lividipennis on GMHT rice or controls fit Beddington＇s model; there were no significant differences in the parameters of numerical responses between GMHT rice Bar68-1 and D68. The results indicated that the functional and numerical responses of C. lividipennis to BPH eggs are not affected by GMHT rice Bar68-1.

Cry1Ab rice does not impact biological characters and functional response of Cyrtorhinus lividipennis preying on Nilaparvata lugens eggs

One concern about the use of transgenic plants is their potential risk to natural enemies. In this study, using the eggs of the rice brown planthopper, Nilaparvata lugens, as a food source, we investigated the effects of Cry1 Ab rice on the biological characteristics and functional response of an important predator Cyrtorhinus lividipennis. The results showed that the survival ability（adult emergence rate and egg hatching rate）, development（egg duration, nymphal developmental duration）, adult fresh weight, adult longevity and fecundity of C. lividipennis on Bt rice plants were not significantly different compared to those on non-Bt rice plants. Furthermore, two important parameters of functional response（instantaneous search rate and handling time） were not significantly affected by Bt rice. In conclusion, the tested Cry1 Ab rice does not adversely impact the biological character and functional response of C. lividipennis.

Improving a method for evaluating alfalfa cultivar resistance to thrips

The thrips quantity ratio（TQR） model is an important tool for evaluating crop resistance to thrips based on the correlation between thrips quantities and cultivars. Unfortunately, it is inaccurate, and the results appear significantly inconsistent when analysing the same cultivars in the same field study. To improve this model, we first studied the resistance of 28 alfalfa cultivars to thrips in Cangzhou, Hebei Province, north China. The results showed that the most suitable evaluation period was from May to June, as the thrips population was stable during this period. Second, we found that the natural enemy population was significantly positively correlated with the thrips population density（R=0.7275, P〈0.0001）, which might influence resistance estimation. Hence, we introduced a parameter ‘α＇, corresponding to the natural enemy quantity ratio, to eliminate the effect of the natural enemy using ＂αTQR＂. Using the improved method, 28 cultivars were clustered into three classes： the resistant class, sensitive class, and median class. All numerical values were calculated for αTQR displayed as a Gaussian distribution. This information showed that all data should be divided into nine groups using a median value of 1±0.1 with an equal difference of 0.1. Based on the new standard cultivars, Gongnong 1, Alfaking, Cangzhou and Algonquin were classified as highly resistant cultivars; Zhongmu 3, Gongnong 2, Zhongmu 1 and Zhongmu 2 were classified in the resistant group; Queen was classified in the moderately resistant group; Derby, WL354HQ, KRIMA, Apex, 53 HR, SARDI 5 and Farmers Treasure were classified in the median class; WL319HQ, WL343HQ and Sitel were classified as the low sensitive group; WL440 HQ and SARDI7 as the moderately sensitive group; WL168HQ and Sanditi as the sensitive group; and SARDI 10, WL363HQ, FD4, WL323 and SOCA as the highly sensitive group.

Assessment of the potential toxicity of insecticidal compounds to Peristenus spretus,a parasitoid of mirid bugs

With the increased cultivation of Bt crops in China,Apolygus lucorum and other mirid bugs have emerged as important agricultural pests because they are insensitive to the Bt proteins.In addition,the reduction of pesticide applications after planting Bt crops also increases the severity of mirid bug outbreaks.Peristenus spretus is a parasitoid of mirid nymphs,but its sensitivity to Bt proteins is not known.In the current study,we developed a dietary exposure assay to assess the effects of Bt proteins(Cry1Ab,Cry1Ac,Cry1F,Cry2Aa,and Cry2Ab)on P.spretus adults using a diet consisting of a 10% honey solution with or without Bt proteins at 400μg g^(-1) diet.The results showed that the survival and reproduction of P.spretus adults were reduced by the cysteine protease inhibitor E-64(a positive control)but were not affected by any of the five Bt proteins.The activities of digestive,detoxifying,and antioxidant enzymes in P.spretus were also unaffected by diets containing the Cry proteins,but they were significantly affected by the diet containing E-64.We then developed a tritrophic bioassay to determine the effects of the five Bt proteins on P.spretus larvae and pupae.In this assay,A.lucorum nymphs fed an artificial diet containing Cry proteins were used as the hosts for P.spretus.The results of the tri-trophic assay indicated that neither the pupation rate nor the eclosion rate of the P.spretus parasitoids were significantly affected by the presence of high concentrations of Bt proteins in the parasitized A.lucorum nymphs.The overall results indicate that these two assays can be used to evaluate the toxicity of insecticidal compounds to P.spretus and that the tested Cry proteins are not toxic to P.spretus.

Flavonoid-producing tomato plants have a direct negative effect on the zoophytophagous biological control agent Oriussauteri

Orius sauteri(Poppius)(Hemiptera:Anthocoridae)is often used for biological control of small arthropod pests in greenhouse vegetable production systems in Asia.In addition to feeding on arthropod prey,O.sauteri consumes small quantities of plant material.Previous studies demonstrated that tomato plant chemistry confers antixenosis resistance to phloem-feeding whiteflies,but the potential nontarget effects of phytochemicals on the beneficial predator O.sauteri are unknown.Comparison of O.sauteri confined to near-isogenic lines(NILs)of tomatoes producing high levels offlavonoids(NIL-purple hypocotyl;resistant to whiteflies)and low levels of flavonoids(NIL-green hypocotyl;susceptible to whiteflies)revealed that O.sauteri had reduced oviposition,nymphal survival,and development on resistant plants,even if they were also provided with prey that did not feed on the host plant.Moreover,O.sauteri showed a significant ovipositional preference in choice assays,laying significantly more eggs on susceptible than on resistant plants.Molecular gut content analysis using the specific chloroplast trnL gene from tomato confirmed that adult and immature O.sauteri feed on both resistant and susceptible genotypes,and feeding behavior assays revealed that resistance did not affect plant feeding or prey acceptance by O.sauteri adults.These results demonstrate a direct negative effect of phytochemicals on a nontarget beneficial species and indicate that resistance mediated by phytochemicals can affect organisms that do not solely feed on phloem sap.The results also indicate that the mode of action and the potential ecological effects of phytochemicalmediated resistance are broader than previously recognized.