Comparative studies of predation among feral,commercially-purchased,and laboratory-reared predators

The predatory activities of commercially-purchased adult Hippodamia convergens Guérin-Méneville and two laboratory-reared strains of adult Geocoris punctipes (Say) were compared with their feral counterparts. In single prey choice feeding tests, commercially-purchased and feral H. convergens were provided copious amounts of silverleaf whitefly, Bemisia argentifolii Bellows & Perring adults or eggs of pink bollworm, Pectinophora gossypiella (Saunders). Commercially-purchased H. convergens devoured more pink bollworm eggs and at a faster rate than the feral H. convergens. In contrast, feral H. convergens consumed more adult whiteflies and at a faster rate than commercial H. convergens. In multiple feeding choice tests, two distinctly different laboratory-reared strains and feral G. punctipes were provided a cotton leaf disk containing copious amounts of silverleaf whitefly eggs, nymphs, and adults. Virtually no predation was observed on whitefly eggs, but both laboratory strains of G. punctipes fed on more whitefly nymphs and adults than the feral G. punctipes. Moreover, both of the laboratory strains had a significantly faster feeding rate on adult whiteflies and spent significantly less time feeding on plant tissue than the feral strain. These results suggest that the augmentative biological control candidates retained their ability to prey on these selected prey items, even after being displaced from their overwintering site (H. convergens) or being reared in captivity (G. punctipes) for over 40 generations. Handling editor: Patrick De Clercq. This article reports the results of research only. Mention of a proprietary product does not constitute an endorsement or a recommendation for its use by the USDA.     

Handling time, prey preference, and functional response for Chrysoperla rufilabris in the laboratory

The predaceous larvae of Chrysoperla rufilabris (Burmeister) exhibited some success-motivated searching, particularly when feeding on Heliothis virescens (F.) eggs, but handling time did not decrease with experience. Handling time for H. virescens larvae was more than twice that for eggs. H. virescens larvae were preferred to cotton aphids (Aphis gossypii (F.)) while aphids were preferred to H. virescens eggs. C. rufilabris larvae exhibited a linear functional response to the three prey types tested, over the prey densities tested.USDA, ARS, Retire. Present address: 200 Highland, College Station, TX 77840, USA     

Influence of larval rearing diet on the intensive searching behaviour ofHarmonia axyridis [Col.: Coccinellidae] Larvae

The capture of prey by last instar larvae of the aphidophagous coccinellidHarmonia axyridis Pallas (Col.,Coccinellidae) modified larval movement so that extensive search was replaced by intensive search. The continuous rearing of this species on eggs ofEphestia kühniella Zell. (Lep.,Pyralidae) or on the aphidAcyrthosiphon pisum Harris (Homopt.,Aphidae) led to conditioning. Only larvae that ate the same prey as they were reared on, adopted intensive searching movements after feeding. Using larvae reared on substitute prey in biological control systems may decrease the efficiency of the released predators.     

Populations of Predaceous Natural Enemies Developing on Insect-Resistant and Susceptible Tomato in North Carolina

Naturally occurring populations of immature and adultGeocoris punctipes,adultColeomegilla maculataand immature coccinellids were monitored on field-grown tomato lines susceptible and resistant toManduca sextaandHelicoverpa zea. Helicoverpa zeaandHeliothis virescenseggs and small larvae that serve as prey for these predators also were monitored. MoreH. zeaandH. virescenseggs and small larvae were found on resistant than on susceptible plant lines. However, similar populations of largeH. zeaandH. virescenslarvae were found on resistant and susceptible plants. The number of adultGeocoris punctipes,adultColeomegilla maculataand immature coccinellids on resistant plants was always as high or higher than the number on susceptible plants. The data demonstrate no incompatibility of host-plant resistance with biological control provided by these predaceous insects, but indicate that the number ofG. punctipesand coccinellids required to provide effective biological control may develop too late in the season to be of practical value. Large populations of stilt bugs (Jalysus wickhami,Hemiptera: Berytidae) and spiders were observed to occur earlier in the growing season than eitherG. punctipesor coccinellids and may be a significant source of mortality forH. zeaeggs and small larvae.     

Prey selection by in vitro- and field-reared Geocoris punctipes

The patterns of prey selection of Geocoris punctipes (Say) (Hemiptera: Lygaeidae), reared continously on artificial diet for six years, were almost identical with patterns shown by their field-derived counterparts.In paired choice experiments both the in vitro-reared and the wild G. punctipes showed a significant preference for Lygus hesperus over Aphis nerii, Heliothis zea, H. virescens, and Spodoptera exigua. There were no significant differences in choices made by the in vitro-reared and the wild G. punctipes. These similar feeding patterns suggest that in vitro rearing, even over extended periods, does not cause degradation in the prey selection characteristics of G. punctipes.     

Expression of Bacillus thuringiensis Cry1Ac protein in cotton plants, acquisition by pests and predators: a tritrophic analysis

1. Studies have shown that Cry proteins of the bacterium Bacillus thuringiensis expressed in transgenic plants can be acquired by nontarget herbivores and predators. A series of studies under field and controlled conditions was conducted to investigate the extent to which Cry1Ac protein from Bt transgenic cotton reaches the third trophic level and to measure the amount of protein that herbivores can acquire and expose to predators. 2. Levels of Cry1Ac in Bt cotton leaves decreased over the season. Among herbivores (four species), Cry1Ac was detected in lepidopteran larvae and the amount varied between species. Among predators (seven species), Cry1Ac was detected in Podisus maculiventris and Chrysoperla rufilabris. 3. In the greenhouse, only 14% of the Cry1Ac detected in the prey (Spodoptera exigua larvae) was subsequently found in the predator P. maculiventris. Detection of Cry1Ac protein in Orius insidiosus, Geocoris punctipes and Nabis roseipennis was probably limited by the amount of prey consumed that had fed on Bt cotton. 4. Purified Cry1Ac was acquired by the small predatory bug G. punctipes but at much higher concentration than found in plants or in lepidopteran larvae. 5. Bt protein was shown to move through prey to the third trophic level. Predatory heteropterans acquired Cry1Ac from prey fed Bt cotton, but acquisition was dependent on the concentration of Cry1Ac conveyed by the prey and the amount of prey consumed. The type and availability of prey capable of acquiring the protein, coupled with the generalist feeding behaviour of the most common predators in the cotton ecosystem, probably constrain the flow of Cry1Ac through trophic levels.     

Geocoris punctipes as a predator of Bemisia tabaci: a laboratory evaluation

Geocoris punctipes (Say), a predaceous lygaeid not previously docmented as a whitefly predator, was tested in the laboratory as a natural enemy of the sweet potato whitefly, Bemisia tabaci (Genn.). Its stalking behavior with whiteflies as prey was similar to that observed with aphids. A previously unobserved behavior was noted that involves the predators using salivary secretions to fasten the wings of prey to various surfaces, allowing labial probing and feeding. Prey consumption as a function of prey number appeared to follow the pattern of the Holling type II functional response. Handling time per prey item ranged from about 180 to 240 seconds. No changes were observed in handling time devoted to earlier versus later catches. Nutritional quality of whiteflies was measured using crude protein, lipids and carbohydrates as criteria. Performance, in terms of predator behavior, total daily handling time, functional response, energy budget and nutritional quality all support the hypothesis that G. punctipes is a promising candidate for biological control of sweet potato whiteflies.     

The non-abundant nutrient (NAN) concept as a determinant of predator-prey fitness

We applied the non-abundant nutrient concept (NAN), an off-shoot from the ecological concept known as Liebig’s “law of the minimum” or the concept of “limiting factors”, to explain why certain predators are well fitted while others are poorly fitted to their prey. The generalist predatorsGeocoris punctipes (Say) (Heteroptera: Lygaeidae) andChrysoperla carnea Stephens (Neuroptera: Chrysopidae) and the specialist predator of whitefliesSerangium parcesetosum Sicard (Coleoptera: Coccinellidae) were compared, nutritionally, to determine their relative propensities for predation onEphestia kuehniella (Zeller) (Lepidoptera: Phycitidae) eggs, silverleaf whitefly nymphsBemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae) andAphis gossypii Glover (Homoptera: Aphididae). Using two prey content parameters, biomass (measured as dry weight) and methionine (the least abundant protein amino acid in all three prey species), we made estimates of how many of the various kinds of prey would need to be consumed to satisfy each predator’s growth requirements to reach the adult stage. From this information and observations regarding developmental periods, prey handling times, extraction efficiencies and conversion efficiencies, we developed a daily time budget for each predator feeding on each of the three types of prey. The number of prey and the time required to satisfy the methionine requirement were generally much greater than the numbers and time required for meeting biomass requirements. Of the three species of predators, onlyS. parcesetosum could survive and reproduce within a reasonable time budget with whiteflies as prey. Cotton aphids also appeared to be a marginal prey with respect to methionine content.     

Behavioural and morphological differences between feral and domesticated strains of common carp Cyprinus carpio

Morphological and behavioural traits of a feral strain of the common carp Cyprinus carpio from Lake Biwa in Japan were compared with those of two domesticated strains reared in Japan (one commercial strain and one ornamental koi). To compare genetically inherited traits, all fish were reared from eggs under similar environmental conditions. Using these fish, the following five traits were compared among the three strains: body shape, consumption rate of two types of free-swimming shrimp, medaka Oryzias latipes and bottom-dwelling chironomid larvae prey items, preference for a bottom habitat, feeding skills in detecting prey and escape response to predator attack. The feral strain of fish had more streamlined bodies, higher consumption rates for free-swimming prey, a greater preference for a bottom habitat, possessed greater skill in detecting prey and were more cautious of predator attacks, compared with the fish of the two domesticated strains. These characteristics shown by the feral fish are probably adaptive to the natural environment. A genetic analysis based on five nuclear single nucleotide polymorphism markers, however, suggested that the feral strain was relatively recently derived from domesticated stocks. Considering this, the present results appear to indicate the possibility that domesticated C. carpio could re-adapt to the wild environment during a short evolutionary period, although further research using more feral strains is required.     

The effect of invertebrate and vertebrate predators on the foraging movements of Ischnura elegans larvae (Odonata: Zygoptera)

SUMMARY.

• 1 The foraging movements of late instar Ischnura elegans larvae were monitored in laboratory experiments to study the effects of predators on larval feeding behaviour.
• 2 Ischnura larvae are sit-atid-wait, or ambush, foragers, moving occasionally between perches in search of profitable feeding sites. Larval foraging movements, monitored at different densities of Daphnia prey, increased significantly when prey were absent.
• 3 In experiments without prey, larval movement was inhibited by the presence of fish predators, as well as by invertebrate predators (Notonecta glauca), but not by closely related, non-predatory invertebrates (Corixa punctata) or physical disturbance of the water (intermittent air bubbles).
• 4 Further experiments varied Ischnura hunger levels (0–8 days without food) and illumination (light or dark) with and without notonectid predators. Hunger had no consistent effect on penultimate instar behaviour but final instar foraging activity was significantly modified: movements increased after 4 days starvation and decreased again after 8 days. This response was suppressed by the presence of predators. Both larval instars moved significantly less often in the light, even when predators were absent.
• 5 These phenotypically flexible predator-avoidance responses are likely to decrease the risk of predation by both visual and tactile predators. However, predators clearly have an important influence on the feeding niche of Ischnura larvae, and may decrease the overall feeding efficiency, growth rate, and survival of larvae by constraining their movement in search of profitable feeding sites.

     

Harmonia axyridis (Coleoptera: Coccinellidae) Exhibits No Preference between Bt and Non-Bt Maize Fed Spodoptera frugiperda (Lepidoptera: Noctuidae)

A recent shift in managing insect resistance to genetically engineered (GE) maize consists of mixing non-GE seed with GE seed known as “refuge in a bag”, which increases the likelihood of predators encountering both prey fed Bt and prey fed non-Bt maize. We therefore conducted laboratory choice-test feeding studies to determine if a predator, Harmonia axyridis, shows any preference between prey fed Bt and non-Bt maize leaves. The prey species was Spodoptera frugiperda, which were fed Bt maize (MON-810), expressing the single Cry1Ab protein, or non-Bt maize. The predators were third instar larvae and female adults of H. axyridis. Individual predators were offered Bt and non-Bt fed prey larvae that had fed for 24, 48 or 72 h. Ten and 15 larvae of each prey type were offered to third instar and adult predators, respectively. Observations of arenas were conducted at 1, 2, 3, 6, 15 and 24 h after the start of the experiment to determine the number and type of prey eaten by each individual predator. Prey larvae that fed on non-Bt leaves were significantly larger than larvae fed Bt leaves. Both predator stages had eaten nearly all the prey by the end of the experiment. However, in all combinations of predator stage and prey age, the number of each prey type consumed did not differ significantly. ELISA measurements confirmed the presence of Cry1Ab in leaf tissue (23–33 µg/g dry weight) and S. frugiperda (2.1–2.2 µg/g), while mean concentrations in H. axyridis were very low (0.01–0.2 µg/g). These results confirm the predatory status of H. axyridis on S. frugiperda and that both H. axyridis adults and larvae show no preference between prey types. The lack of preference between Bt-fed and non-Bt-fed prey should act in favor of insect resistance management strategies using mixtures of GE and non-GE maize seed.     

Prey stage preference and functional response of the predatory mite Galendromus flumenis to Oligonychus pratensis

The Banks grass mite, Oligonychus pratensis (Banks) (Acari: Tetranychidae), is a serious pest in dates (Phoenix dactylifera L.) in the New World. Currently O. pratensis is managed using the miticide, Savey, and alternative strategies are necessary to remove pressure from a single control method due to the risk of resistance evolution. For this purpose, studies are underway to develop biological control strategies using the predatory mite, Galendromus flumenis (Chant) (Acari: Phytoseiidae). The current study determined the consumption rate of G. flumenis at constant densities of O. pratensis eggs, larvae, protonymphs and deutonymphs, and defined the functional response of predator females. The predator consumed significantly more eggs than other prey stages, and displayed a type II functional response on all prey stages. The highest attack rate and shortest handling time were obtained for predators feeding on prey larvae and eggs, respectively. The proportions of prey consumed by G. flumenis were higher at lower densities for all stages of Banks grass mite, implying that G. flumenis should be more effective at suppressing Banks grass mite populations at lower densities. Therefore, in an augmentative release program, G. flumenis would need to be released early in the infestation.     

Prey perception of predation risk: volatile chemical cues mediate non-consumptive effects of a predator on a herbivorous insect

Predators can affect prey in two ways—by reducing their density (consumptive effects) or by changing their behavior, physiology or other phenotypic traits (non-consumptive effects). Understanding the cues and sensory modalities prey use to detect predators is critical for predicting the strength of non-consumptive effects and the outcome of predator–prey encounters. While predator-associated cues have been well studied in aquatic systems, less is known about how terrestrial prey, particularly insect larvae, detect their predators. We evaluated how Colorado potato beetle, Leptinotarsa decemlineata, larvae perceive predation risk by isolating cues from its stink bug predator, the spined soldier bug, Podisus maculiventris. When exposed to male “risk” predators that were surgically manipulated so they could hunt but not kill, beetles reduced feeding 29 % compared to controls. Exposure to risk females caused an intermediate response. Beetles ate 24 % less on leaves pre-exposed to predators compared to leaves never exposed to predators, indicating that tactile and visual cues are not required for the prey’s response. Volatile odor cues from predators reduced beetle feeding by 10 % overall, although male predators caused a stronger reduction than females. Finally, visual cues from the predator had a weak effect on beetle feeding. Because multiple cues appear to be involved in prey perception of risk, and because male and female predators have differential effects, beetle larvae likely experience tremendous variation in the information about risk from their local environment.     

Variation in prey-specific consumption rates and patterns of field co-occurrence for two larval predaceous diving beetles

Freshwater predatory insects can exert strong effects on prey, although how multiple similar predators may coexist is not well understood. Larval predaceous diving beetles are often numerically and taxonomically abundant predators in lentic systems, but the proximate mechanisms that explain their high abundance remain unknown. Field surveys were conducted twice in June in ponds in Alberta, Canada to assess the associations between larvae of two genera (Graphoderus, Rhantus), their spatial locations, and correlations with potential prey. Both larvae were common and positively correlated within wetlands although neither varied with pond depth nor distance from edge. Laboratory trials indicated that Graphoderus consumed more prey (corixids) at the surface, whereas Rhantus killed benthic prey (chironomids) and corixids at an equal rate; damselflies were the least consumed prey. Predation also varied with depth, with both larvae feeding at higher rates in the shallowest environments compared to Graphoderus at an intermediate depth. Predator–prey correlations from ponds were mostly congruent with predation trials; Graphoderus was positively correlated with corixids, Rhantus was positively correlated with corixids and chironomids; beetles were uncorrelated with damselflies. Reliance on different prey in different microhabitats may be an important mechanism for the maintenance of high abundance of dytiscid larvae.     

Antipredator response of pea aphids <Emphasis Type="Italic">Acyrthosiphon pisum</Emphasis> (Hemiptera: Aphididae): effects of predation risks from an alternative patch on a current patch

To escape from predators, herbivorous prey could leave their current patch and relocate to an alternative patch. However, when other predators are present on the new patch, prey are again exposed to predation risk. Thus, patch leaving might be affected by the other predators. We studied patch leaving of pea aphids Acyrthosiphon pisum Harris (Hemiptera: Aphididae) in response to ladybird larvae Harmonia axyridis Pallas (Coleoptera: Coccinellidae) on broad bean Vicia faba L. shoots that were offered as patches for aphids. We tested whether shoot leaving was affected by the presence of predators on alternative shoots under laboratory conditions. Odors from alternative shoots were evaluated as possible cues used by aphids to assess predation risk on the shoots. We exposed aphids to odors from alternative shoots with conspecifics plus either adult or larval ladybirds or larval green lacewings Mallada desjardinsi Navas (Neuroptera: Chrysopidae). Shoot leaving was reduced only when adult ladybirds were present on the alternative shoots compared with controls (i.e., no predators on the alternative shoots). Odors of both adult ladybirds and of conspecifics being attacked by ladybird larvae were required for reduced leaving. Hence, predation risks on current and alternative patches might affect the antipredator responses of aphids.     

Prey detection of aquatic predators: Assessing the identity of chemical cues eliciting prey behavioral plasticity

Chemical cues transmitted through the environment are thought to underlie many prey responses to predation risk, but despite the known ecological and evolutionary significance of such cues, their basic composition are poorly understood. Using anuran tadpoles (prey) and dragonfly larvae (predators), we identified chemical cues associated with predation risk via solid phase extraction and mass spectrometry of the extracts. We found that dragonfly larvae predators consistently produced a negative ion, m/z 501.3, when they fed on bullfrog (Rana catesbeiana) and mink frog (Rana septentrionalis) tadpoles, but this ion was absent when dragonflies were fasted or fed invertebrate prey. When tadpole behavioral responses to dragonfly chemical cues were examined, tadpoles reduced their activity, particularly in response to dragonflies feeding on tadpoles. Furthermore, a negative correlation was noted between the level of tadpole activity and the concentration of the m/z 501.3 compound in dragonfly feeding trials, indicating that this ion was possibly responsible for tadpole anti-predator behavior.     

Responses of Episyrphus balteatus DeGeer (Diptera: Syrphidae) in relation to prey density and predator size

Laboratory experiments were conducted to determine the functional and numerical responses of the aphidophagous hover fly Episyrphus balteatus DeGeer (Diptera: Syrphidae) to different densities of 4th instar black bean aphids, Aphis fabae Scopoli (Homoptera: Aphididae), on broad bean, Vicia faba L. (Fabaceae). Two different-sized larvae of predators were tested in different densities of similar-sized prey to determine whether functional response parameters depended on the body sizes of predator and prey. In numerical response experiments, gravid E. balteatus females were exposed individually to different densities of 4th instars of A. fabae on cut sections of the broad bean plant, V. faba L. Logistic regression suggested a type II functional response for both larval sizes of E. balteatus. The searching efficiency (a) of the larger larvae was higher than that of the smaller ones. Prey consumption was higher, and handling time (T_h) was lower for larger larvae than smaller ones. The theoretical maximum number of A. fabae nymphs eaten by the different-sized larvae was 125 and 269 nymphs per day. Larger E. balteatus larvae are more efficient predators for aphid management strategies. The reproductive numerical response, in terms of the number of eggs laid, increased curvilinearly with increasing prey density, but the proportion of eggs laid (egg number/prey density) decreased as the initial density of prey increased.     

The costs of reduced feeding due to predator avoidance: potential effects on growth and fitness in Ischnura elegans larvae (Odonata: Zygoptera)

ABSTRACT.

• 1 This paper investigates the behaviour, in the laboratory, of a forager simultaneously confronted with the conflicting needs to feed and to avoid predators. The foragers were larvae of the damselfly Ischnura elegans Van der Linden, feeding on Daphnia magna Strauss. The predators were adult females of Notonecta glauca L.
• 2 Patch choice by Ischnura larvae was significantly modified by the presence of predators. Larvae moved to feed in patches of high prey density when predators were absent but preferred dense cover, even though virtually no prey were available, when predators were present. This behaviour was not altered by hunger, up to 12 days without food. In other words, Ischnura larvae were risk averse in their foraging behaviour.
• 3 In experiments with abundant prey available, the feeding rates of Ischnura larvae confined to a single patch were also significantly reduced by the presence of hydrodynamically and chemically detectable predators. Predators detectable only by vision had little effect.
• 4 Calculations made from published data show that reduced larval feeding rates can lead to slower growth and development and prolonged instar durations in Ischnura elegans larvae. This may have important consequences for larval survival and adult reproductive fitness.

     

Assessment of the functional response parameters of Coccinella septempunctata to varying densities of Acyrthosiphon pisum

The functional response of a predator describes the rate at which it kills its prey at different prey densities and is, therefore, an important tool to determine the efficiency of a predator in regulating the population dynamics of a prey. We investigated the functional response of Coccinella septempunctata L. (Coleoptera: Coccinellidae) to varying densities of Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). The results revealed that the linear coefficient, P₁ in the reduced logistic model was found significantly negative for the 4^th instar larvae and adult male and female of C. septempunctata (?0.002, ?0.004 and???0.002, respectively) indicating a type II functional response. The parameter estimates of adult male, female and 4^thinstar larvae of C. septempunctata calculated through Holling's disc model revealed that the highest attack rate (a) (1.047?±?0.014), shortest handling time (T_h) (0.0984?±?0.024?h) and largest maximum capture rate (T/T_h) (243.902) was exhibited by female. Parameter estimates calculated through Rogers’s equation also showed the same sequence where maximum attack rate (a) of 0.00256?±?0.0003 was exhibited by female followed by 4^th instar larvae (0.00251?±?0.0005). The shortest handling time (T_h) (0.210?±?0.003?h) and highest maximum capture rate (T/T_h) (114.17) was also exhibited by female. Comparison of functional response curves of adult male, female and 4^th instar larvae revealed that maximum consumption of prey at all the densities offered was shown by female followed by 4^thinstar larvae. The study manifested that C. septempunctata could be an efficient biocontrol agent of pea aphid, A. pisum.     

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.