Life history characteristics of Frankliniella occidentalis on cucumber leaves with and without supplemental food

The development time, fecundity, longevity, and resultant intrinsic growth rate of the western flower thrips Frankliniella occidentalis (Pergande) [Thysanoptera: Thripidae] encaged on a cucumber leaf were compared among seven types of food supplied: six pollen species and a mixture of milk powder and yeast. The rationale was to find a food source that offers the least benefit for thrips and could therefore be considered as a food source for the preventative introduction of thrips predators. With the exception of the mixture of milk powder and yeast, all the food sources tested offered a nutritional benefit for the thrips. The addition of pollen increased fecundity and reduced development time, mainly during the larval stage. Betula pubescens and Corylus avellana pollen also increased adult longevity. The nutritional benefit of Pinus sylvestris pollen was greater than that of the other five pollen species, as manifested by its significantly greater positive effect on fecundity. The other pollen species could not be ranked in terms of nutritional benefit to F. occidentalis. The negative effect of the milk powder plus yeast mix on the life‐table parameters of F. occidentalis probably only occurs in an encaged situation where thrips cannot escape from the unfavorable environment. The crude estimate of the intrinsic growth rate of F. occidentalis increased from 0.163 on the plain cucumber leaf to 0.240 when P. sylvestris pollen was added to the leaf. The differences in intrinsic growth rate mainly reflect the differences in fecundity among the food sources. Thus, the peak oviposition rate may be used as a measure of the nutritional benefit F. occidentalis can obtain by feeding on supplemental food sources. The positive effect of a supplemental food source on thrips does not necessarily mean it is unsuitable for the preventative introduction of thrips predators, because the supplemental food can also affect the population dynamics of the predator and the predator–prey interaction and, hence, the outcome of biological control.     

Ovipositing Orius laevigatus increase tomato resistance against Frankliniella occidentalis feeding by inducing the wound response

The anthocorid predator Orius laevigatus is widely used as biological control agent of thrips pests, including the western flower thrips Frankliniella occidentalis. In the current study, it was shown that O. laevigatus adults can increase plant resistance to feeding damage of F. occidentalis on tomato plants. The predator elicits a jasmonic acid (JA) mediated wound response during endophytic oviposition, resulting in reduced thrips feeding. A strong accumulation of H₂O₂, a molecule involved in different parts of the wound response, in leaf tissue surrounding the predator eggs or oviposition puncture sites was observed. Infestation of tomato plants with adult predators led to the upregulation of three JA regulated wound responsive genes: the precursor prosystemin, the jasmonic acid biosynthesis enzyme allene oxide synthase and the defence protein proteinase inhibitor I. Likewise, the presence of adults caused accumulation of proteinase inhibitor II, a principal marker for the wound response.     

A one‐step,single tube,duplex PCR to detect predation by native predators on invasive Bemisia tabaci MEAM1 and Frankliniella occidentalis

Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae) and Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), two important invasive species, are serious agricultural pests. In this study, a one‐step, single tube, duplex polymerase chain reaction (PCR) procedure was developed to allow rapid, specific, and sensitive identification of B. tabaci MEAM1 and F. occidentalis in predator guts. The system and conditions used for the duplex PCR were optimized. The species specificity of the duplex PCR determined by comparison against non‐targets that might interact with B. tabaci MEAM1 and F. occidentalis showed that oligonucleotide primers amplified nuclear gene target sequences present only in B. tabaci MEAM1 or F. occidentalis. The limits of detection were 9.53 ng μl^?1 for B. tabaci MEAM1 and 8.94 ng μl^?1 for F. occidentalis. Within a field cage study, in which predators Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) and Orius sauteri (Poppius) (Hemiptera: Anthocoridae) were allowed to feed on B. tabaci MEAM1 and F. occidentalis for 10 h, the B. tabaci MEAM1 DNA was detectable in 100% of H. axyridis and O. sauteri, and F. occidentalis DNA was detectable in 80% of H. axyridis and 90% of O. sauteri; this implicated that B. tabaci MEAM1 and F. occidentalis remains could be detected in native predator guts simultaneously. The accuracy and reliability of the assay suggested strongly that the duplex PCR optimized for B. tabaci MEAM1 and F. occidentalis is sensitive and specific for both invasive insects and is therefore useful in early diagnosis and monitoring of B. tabaci MEAM1 and F. occidentalis infections, and can be used to identify domestic predator species and food web relationships.     

An Entomopathogenic Strain of Beauveria bassiana against Frankliniella occidentalis with no Detrimental Effect on the Predatory Mite Neoseiulus barkeri: Evidence from Laboratory Bioassay and Scanning Electron Microscopic Observation

Among 28 isolates of Beauveria bassiana tested for virulence against F. occidentalis in laboratory bioassays, we found strain SZ-26 as the most potent, causing 96% mortality in adults at 1×10⁷ mL⁻¹conidia after 4 days. The effect of the strain SZ-26 on survival, longevity and fecundity of the predatory mite Neoseiulus (Amblyseius) barkeri Hughes were studied under laboratory conditions. The bioassay results showed that the corrected mortalities were less than 4 and 8% at 10 days following inoculation of the adult and the larvae of the predator, respectively, with 1×10⁷ conidia mL⁻¹ of SZ-26. Furthermore, no fungal hyphae were found in dead predators. The oviposition and postoviposition durations, longevity, and fecundity displayed no significant differences after inoculation with SZ-26 using first-instar larvae of F. occidentalis as prey in comparison with untreated predator. In contrast, the preoviposition durations were significantly longer. Observations with a scanning electron microscope, revealed that many conidia were attached to the cuticles of F. occidentalis at 2 h after treatment with germ tubes oriented toward cuticle at 24 h, penetration of the insect cuticle at 36 h, and finally, fungal colonization of the whole insect body at 60 h. In contrast, we never observed penetration of the predator''s cuticle and conidia were shed gradually from the body, further demonstrating that B. bassiana strain SZ-26 show high toxicity against F. occidentalis but no pathogenicity to predatory mite.     

Comparison of the predation capacities of two soil-dwelling predatory mites,Gaeolaelaps aculeifer and Stratiolaelaps scimitus (Acari: Laelapidae), on three thrips species

Soil-dwelling predatory mites are natural enemies of various soil pest insects and mites. Both Gaeolaelaps aculeifer (Canestrini) and Stratiolaelaps scimitus (Womersley) are commercialized natural enemies of thrips, but there is little information on the predation rate of these predatory mites on different thrips species. We compared their predation capacities on three thrips species, Frankliniella occidentalis, F. intonsa, and Thrips palmi, which are major pests of various horticultural plants. The predatory rate of G. aculeifer was higher than that of S. scimitus. Both predator species fed on more T. palmi thrips than F. occidentalis or F. intonsa thrips, which may be attributable to the smaller body size of T. palmi than the other thrips. Predation rates of female adults were 2.6–2.8 times higher than those of deutonymphs in both species. Predation rates were not separated according to the various developmental stages (i.e., second instar larva, pupa, or adult) of thrips; however, deutonymphs fed on fewer adults than larvae or pupae of F. occidentalis. Our results suggest that both G. aculeifer and S. scimitus are active predators that can prey during any of their developmental stages and on any species of thrips tested.     

Interaction between life stages in a phytoseiid predator: western flower thrips prey killed by adults as food for protonymphs of Amblyseius cucumeris

Alternative feeding strategies are important in determining the lifestyle of polyphagous spider mite prodators, and could play a key role in their use for biocontrol of prey such as thrips. The small size of Amblyseius cucumeris relative to western flower thrips, Frankliniella occidentalis, limits its survival and development when this prey is the only food available. We show that when A. cucumeris nymphs were reared either alone or with a gravid female on live larvae of F. occidentalis as the only source of food, survival was increased and development was accelerated by the presence of the adult. Similar performance by predator nymphs reared alone on freshly killed thrips larvae indicated that those nymphs reared on live prey with an adult were benefiting from feeding on prey killed by the adult. Variation of the period when an adult female was present with the nymph showed that food provided as a result of the adult's preying activities was beneficial until approximately one third through nymphal development, after which protonymphs became independent predators, with good survival and rapid development when provided only with live F. occidentalis larvae. The results are discussed in relation to adult dispersal in specialist as opposed to generalist phytoseiids, and its potential manipulation in using A. cucumeris for thrips biocontrol.     

Interactions of two natural enemies of Tetranychus urticae,the fungal entomopathogen Beauveria bassiana and the predatory mite,Phytoseiulus persimilis

The effect of either untreated or treated adults of the spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) by Beauveria bassiana (Bals.) Vuillemin (Ascomycota: Hypocreales) DEBI008 at 1×10⁶ (conidia/ml) was investigated on developmental stages and life table parameters of Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) under laboratory conditions. Four time intervals (0, 24, 48 and 72 h post-inoculation of spider mites) were considered for studying the predator characteristics as different treatments. Duration of each life stage, longevity, reproduction rate, intrinsic rate of natural increase (r _m ), net reproductive rate (R ₀), mean generation time (T) and finite rate of increase (λ) of the P. persimilis were calculated on both untreated and B. bassiana treated spider mite adults. Data analysis showed that longevity and fecundity of predatory mites fed on untreated and treated mites (time interval 0) were higher in comparison with other time intervals after inoculation. The entomopathogenic fungus adversely affected longevity and fecundity of the predatory mite. Fertility life table parameters of predatory mites fed on T. urticae treated by B. bassiana at different time intervals showed that T, R ₀, λ and r _m are strongly affected by the fungus presence and these parameters had significant differences among time treatments. The least r _m value was observed in the time interval of 72 h post-inoculation. The fitness of T. urticae was affected by B. bassiana 24, 48 and 72 h post-inoculation of mite adults, and consequently it caused decreased longevity of P. persimilis and accordingly a decrease in the intrinsic rate of natural increase of the predator.     

Oviposition patterns in a predatory mite reduce the risk of egg predation caused by prey

Abstract 1. Predatory arthropods lay their eggs such that their offspring have sufficient prey at their disposal and run a low risk of being eaten by conspecific and heterospecific predators, but what happens if the prey attacks eggs of the predator? 2. The egg distribution and time allocation of adult female predatory mites Iphiseius degenerans as affected by predation of their eggs by prey, the western flower thrips Frankliniella occidentalis, were studied on sweet pepper plants. The predatory mites attack the first instar of thrips but all active stages of thrips are capable of killing the eggs of the predator; however the predatory mite is used for biological control of thrips. 3. The majority of predatory mite eggs was laid on the underside of leaves in hair tufts (domatia). During the experiment, females spent increasing amounts of time in flowers where they fed on pollen and thrips larvae. The risk of predation on predator eggs by thrips was lower on leaves than in flowers where the majority of thrips resides. Moreover, predation risk was higher outside leaf domatia than inside. 4. This suggests that predators avoid ovipositing in places with abundant prey to prevent their eggs from being eaten by thrips.     

Population abundance and movement of Frankliniella species and Orius insidiosus in field pepper

1 A recent study revealed the capacity of the Orius insidiosus to suppress populations of Frankliniella spp. in field pepper during the spring when thrips are rapidly colonizing and reproducing. In this study, population abundance in pepper during spring, summer, and autumn was determined to understand better predator/prey dynamics under local conditions. Local movement between pepper flowers also was quantified to examine how population attributes of the predator allow suppression of rapidly moving populations of prey. 2 Randomized complete block experiments established in the autumn of 1998 and the spring of 1999 included treatments of biological and synthetic insecticides, which altered the population densities of predator and prey. Numbers of O. insidiosus in relation to prey were sufficient in 1998 to prevent build‐up of thrips populations. In 1999, populations of thrips were unable to recover from near extinction owing to persistence of the predator. The predator rapidly recolonized plots treated with insecticide. 3 Greenhouse plants of the same age as field plants were used to monitor movement by predators and prey. Movement by F. occidentalis was limited, whereas F. tritici and F. bispinosa moved rapidly to the greenhouse plants. The males of each thrips species moved more rapidly than the females. There was evidence that rapid movement assisted F. tritici and F. bispinosa in avoiding predation, but O. insidiosus also moved very rapidly to the greenhouse plants. This attribute explains the predator's ability to suppress thrips rapidly even when populations are rapidly colonizing and reproducing in the flowers.     

Olfactory response of the anthocorid predatory bug Orius sauteri to thrips-infested eggplants

The predator Orius sauteri (Poppius) (Heteroptera: Anthocoridae) is an effective arthropod natural enemy of thrips, especially Thrips palmi Karny (Thysanoptera: Thripidae), a serious pest of vegetables. First, we studied O. sauteri's response to the odour from thrips-infested eggplant [Solamum melongena L. (Solanaceae)] in a laboratory by two-choice experiments using a Y-tube olfactometer. When detached eggplant leaves were used as odour sources, O. sauteri preferred the volatiles from uninfested leaves to clean air. Concerning preferences among differently infested leaves, O. sauteri preferred the volatiles from plants infested with 10–100 thrips per leaf to uninfested leaves, but showed no significant preference for artificially damaged leaves over uninfested leaves. Similar results were obtained when complete plants were tested as the odour source. Second, release and recapture experiments in a greenhouse, a more realistic set of conditions, were conducted to confirm whether a significant preference for infested plants occurred at similar infestation levels as in the laboratory. Trends favouring infested plants were detected at densities of five and 500 thrips per plant; however, at the five thrips per plant, this trend was due to the large deviation seen in infested plants in only one replicate. In light of the low tolerable thrips density of eggplant, it is necessary to confirm whether artificial treatments with chemicals induce the emission of herbivore-induced plant volatiles that can attract O. sauteri and prolong its residence time on the leaf.     

西花蓟马高毒力虫生真菌筛选及其生防应用潜力的研究进展

西花蓟马是一种外来入侵的世界性害虫,对农林业危害巨大。查阅国内外相关文献,综述了当前防治西花蓟马的虫生真菌的种类、高毒力菌株的筛选及防治现状。现已知西花蓟马的寄生病原真菌有5种,包括蜡蚧轮枝菌(半知菌:丝孢目)、球孢白僵菌(半知菌:丝孢目)、金龟子绿僵菌(半知菌:丝孢目)、玫烟色棒束孢(半知菌:束梗孢目)和小孢新接霉。其中,球孢白僵菌、金龟子绿僵菌在西花蓟马的生物防治中应用最广,具有良好的开发应用潜力,部分防效好的虫生真菌已申请专利及实现工厂化生产。     

Performance of the predator Amblyseius swirskii (Acari: Phytoseiidae) on greenhouse eggplants in the absence and presence of pine Pinus brutia (Pinales:Pinaceae) pollen

In Turkey, the western thrips Frankliniella occidentalis (Pergande) is a key pest affecting eggplants grown in greenhouses for which an appropriate control strategy is under investigation. It was observed in a previous study that the release of the beneficial predatory mite Amblyseius swirskii (Athias‐Henriot) alone did not result in an effective control of thrips on eggplants. Since pollen is known to improve control efficiency of predators, this study was undertaken to investigate if provision of pollen to eggplants can greatly improve the efficiency of A. swirskii in controlling thrips. The experiments were carried out in both greenhouse and low tunnel. The provision of pollen led to a significant increase in the predator population density on the eggplants but did not result in an effective control of the thrips populations. In this paper, various factors are discussed that could have affected the efficiency of the predatory mite in controlling F. occidentalis on eggplants.     

Differential predation by the generalist predator Orius insidiosus on congeneric species of thrips that vary in size and behavior

We investigated interactions between the generalist predator Orius insidiosus (Say) (Heteroptera: Anthocoridae) and two species of thrips prey, Frankliniella bispinosa (Morgan) and Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), and interspecific differences in morphology and behavior between these prey species that could contribute to differences in predation by O. insidiosus. Frankliniella occidentalis is significantly larger than F. bispinosa. Frankliniella bispinosa has greater mobility compared with F. occidentalis. When O. insidiosus was offered either F. bispinosa or F. occidentalis as prey in single species trials, there were no significant differences in the number of prey captured. However, O. insidiosus had significantly more encounters with F. bispinosa than with F. occidentalis. In arenas with equal numbers of both species, O. insidiosus encountered and captured F. occidentalis more than F. bispinosa. In large arenas with two pepper plants (Capsicum annuum L.), O. insidiosus preyed on more F. occidentalis than on F. bispinosa. These results indicate that O. insidiosus can prey on both thrips species, but that it preferentially captures F. occidentalis. The greater locomotion and movement of F. bispinosa, perhaps combined with its smaller size, allow it to evade predation by O. insidiosus better than F. occidentalis. Consequently, the observed preference of O. insidiosus for F. occidentalis is not exclusively a function of active selection by the predator but also could arise from inherent differences among prey. We propose this differential predation as a mechanism contributing to observed differences in the temporal dynamics of these species in pepper fields.     

Influence of humidity on the infection of western flower thrips, <Emphasis Type="Italic">Frankliniella occidentalis</Emphasis> (Thysanoptera: Thripidae), by <Emphasis Type="Italic">Beauveria bassiana</Emphasis>

The insecticidal activity of Beauveria bassiana GHA derived from a commercial mycoinsecticide BotaniGard ES against Frankliniella occidentalis was determined in a bioassay by dipping the female adults into a conidial suspension. The 90% lethal concentration of B. bassiana GHA was estimated to be 9.7 × 10⁶ conidia/ml. The lethal times for achieving 90% mortality of thrips inoculated with a 1/500-diluted solution of BotaniGard ES and a 10^7.5 (3.16 × 10⁷) conidia/ml suspension of B. bassiana GHA were estimated to be five and six days, respectively. When the treated thrips were exposed to a high relative humidity (RH) of over 99% for various periods and then transferred to 60% RH, the requisite lengths of the high-humidity period to achieve 90% mortality of the thrips at six days after inoculation were estimated to be 46 and 47 h in BotaniGard ES and B. bassiana GHA, respectively. Fungal multiplication in the thrips was detected between 48 to 60 h after inoculation by measuring Beauveria-specific DNA in the host following inoculation with a B. bassiana GHA suspension of 10^7.5 conidia/ml using a real-time quantitative PCR. The mycelial growth in the host hemocoel was not influenced by the low-humidity condition.     

Response of the Wasp Cephalonomia tarsalis (Hymenoptera: Bethylidae) to Beauveria bassiana (Hyphomycetes: Moniliales) as Free Conidia or Infection in Its Host, the Sawtoothed Grain Beetle, Oryzaephilus surinamensis (Coleoptera: Silvanidae)

Cephalonomia tarsalis, an ectoparasitoid, and Beauveria bassiana, an entomopathogenic fungus, are potential biological control agents for the sawtoothed grain beetle, Oryzaephilus surinamensis. Several experiments were conducted to determine whether the two beneficial organisms are compatible. Wasps exhibited little avoidance behavior toward the fungus. Adult wasps oviposited on B. bassiana-infected larvae up to within 1 day of the host's death and the appearance of red fungal pigment. Wasp larvae are susceptible to the fungus and die within 1 day of oviposition on host larvae with mycosis. A 3-h exposure of adult wasps to 100 mg of B. bassiana/kg of wheat resulted in 52.7% mortality. Nevertheless, the wasps entered into grain containing B. bassiana conidia as freely as they entered into conidia-free grain. The mean prevalence of B. bassiana in 46 samples of pooled wheat representing 276 locations was 7.5 colony-forming units/g of wheat. Natural C. tarsalis exposure to B. bassiana in untreated stored wheat is likely to be below lethal quantities, and the introduction of the fungus in insecticidal quantities would have a negative impact on C. tarsalis populations.     

Life-history parameters of western flower thrips on susceptible and resistant cucumber genotypes

The life-history parameters reproduction rate, developmental time and age specific survival of the western flower thrips,Frankliniella occidentalis (Pergande) [Thysanoptera: Thripidae], were determined on susceptible and resistant cucumber (Cucumis sativus L.) genotypes. Both newly emerged andF. occidentalis females of mixed ages showed a substantial reduction (36 to 50%) of the reproduction rate on all resistant genotypes, in particular after the second day. On the resistant genotypes 9127 and 9140,F. occidentalis had a prolonged developmental period. This was primarily due to a prolongation of the second larval stage. On all resistant genotypes,F. occidentalis suffered from high (82 to 97%) preadult mortality, predominantly at the second larval stage. It is conclude that the resistant genotypes do not cause an immediate intoxication of adult nor preadult thrips stages.     

Long-term storage stability of Beauveria bassiana ERL836 granules as fungal biopesticide

Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) ERL836 has been commercialized under the name ChongchaeSak to control an agricultural insect pest, the western flower thrips Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), in the Republic of Korea. As soon as it was launched in 2017, it became a popular product and has received a positive response. However, study of the storage stability of the fungus ERL836 has yet to be investigated. To determine the optimum conditions for long-term storage, we assessed conidial viability and insecticidal activity of B. bassiana ERL836 according to storage temperature and culture substrate. Viability of B. bassiana ERL836 conidia from mycotized grains (millet and rice) stored at low (4 °C) and moderate (25 and 30 °C) temperatures was maintained at >85% for 24 and 18 months, respectively, along with insecticidal activity. In contrast, the samples stored at 37 °C showed low germination rate (about 80% germination rate for only 5 months). This result suggests that low and moderate temperatures (4 to 30 °C) conserve B. bassiana ERL836 viability and virulence.     

Provision of astigmatid mites as supplementary food increases the density of the predatory mite Amblyseius swirskii in greenhouse crops,but does not support the omnivorous pest,western flower thrips

Astigmatid mites can be used as prey for mass rearing of phytoseiid predators, but also as a supplemental food source to support predator populations in crops. Here we evaluated the potential of six species of astigmatid mites (living or frozen) as alternative food for the predatory mite Amblyseius swirskii Athias-Henriot in greenhouse crops. All prey mites tested were suitable for predator oviposition. In general, oviposition was greater when prey mites were reared on dog food with yeast than when they were reared on wheat bran with yeast. Amongst prey items provided as frozen diet, larvae of Thyreophagus entomophagus (Laboulbene), Acarus siro L. and Lepidoglyphus destructor (Schrank) that had been reared on dog food with yeast, resulted in the highest oviposition rates of A. swirskii. T. entomophagus larvae as frozen diet resulted in the shortest preimaginal developmental time of A. swirskii. On chrysanthemum plants, we found that the greatest increase in predator density occurred when living mites of T. entomophagous were used as a food source. This increase was greater than when predators were fed cattail pollen, a commonly used supplemental food. Effects on predators of providing living A. siro and L. destructor, or frozen larvae of T. entomophagous as food, were comparable with provision of pollen. Use of supplemental food in crops can be a risk if it is also consumed by omnivorous pests such as western flower thrips, Frankliniella occidentalis Pergande. However, we showed that both frozen and living mites of T. entomophagous were unsuitable for thrips oviposition. Hence, we believe that provision of prey mite species increases A. swirskii density, supporting biological control of thrips and other pests in greenhouse crops.

     

Distributions of western flower thrips (Thysanoptera: Thripidae) and its predatory bug Orius niger (Hemiptera: Anthocoridae) assessed by coloured sticky traps and plant samplings in cotton

The capturing efficiency of four coloured (yellow, green, white and blue) sticky traps, placed at the top, middle and bottom strata of cotton plants, was tested for the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), and its predatory bug, Orius niger (Wolff) (Hemiptera: Anthocoridae), as well as spatial distributions of both insects on the plant in years 2006 and 2007. The white coloured trap was the most attractive to F. occidentalis and O. niger in the 2-year study. The blue coloured trap was the least attractive for Orius. The mean numbers of F. occidentalis and O. niger on the top plant parts (flowers and leaves) and in all coloured traps positioned on the upper parts of the plants were greater than those found in the lower two strata. Taylor's power law analysis showed that F. occidentalis and O. niger adults aggregated in the flowers or on the leaves. This study suggests that top flowers could be preferentially sampled to determine population densities of Frankliniella flower thrips and Orius species in cotton, and thus, sticky traps should be placed on the top level of plants. F. occidentalis: O. niger ratios in the flowers varied from 4 to 60 thrips per Orius adult in the three plant strata. This result may indicate that F. occidentalis experiences more predation from Orius.     

Interactions of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> Cry1Ac toxin in genetically engineered cotton with predatory heteropterans

A number of cotton varieties have been genetically transformed with genes from Bacillus thuringiensis (Bt) to continuously produce Bt endotoxins, offering whole plant and season-long protection against many lepidopteran larvae. Constant whole-plant toxin expression creates a significant opportunity for non-target herbivores to acquire and bio-accumulate the toxin for higher trophic levels. In the present study we investigated movement of Cry1Ac toxin from the transgenic cotton plant through specific predator-prey pairings, using omnivorous predators with common cotton pests as prey: (1) the beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), with the predator Podisus maculiventris (Heteroptera: Pentatomidae); (2) the two-spotted spider mite, Tetranychus urticae (Acarina: Tetranychidae), with the predatory big-eyed bug Geocoris punctipes (Heteroptera: Geocoridae) and (3) with the predatory damsel bug Nabis roseipennis (Heteropera: Nabidae); and (4) the thrips Frankliniella occidentalis (Thysanoptera: Thripidae) with the predatory pirate bug Orius insidiosus (Heteroptera: Anthocoridae). We quantified Cry1Ac toxin in the cotton plants, and in the pests and predators, and the effects of continuous feeding on S. exigua larvae fed either Bt or non-Bt cotton on life history traits of P. maculiventris. All three herbivores were able to convey Cry1Ac toxin to their respective predators. Among the herbivores, T. urticae exhibited 16.8 times more toxin in their bodies than that expressed in Bt-cotton plant, followed by S. exigua (1.05 times), and F. occidentalis immatures and adults (0.63 and 0.73 times, respectively). Of the toxin in the respective herbivorous prey, 4, 40, 17 and 14% of that amount was measured in the predators G. punctipes, P. maculiventris, O. insidiosus, and N. roseipennis, respectively. The predator P. maculiventris exhibited similar life history characteristics (developmental time, survival, longevity, and fecundity) regardless of the prey’s food source. Thus, Cry1Ac toxin is conveyed through non-target herbivores to natural enemies at different levels depending on the herbivore species, but continuous lifetime contact with the toxin by the predator P. maculiventris through its prey had no effect on the predator’s life history. The results found here, supplemented with others already published, suggest that feeding on Cry1Ac contaminated non-target herbivores does not harm predatory heteropterans and, therefore, cultivation of Bt cotton may provide an opportunity for conservation of these predators in cotton ecosystems by reducing insecticide use.