The effects of insect-resistant genetically engineered rice producing Cry1C protein derived from ... more The effects of insect-resistant genetically engineered rice producing Cry1C protein derived from Bacillus thuringiensis (Bt) on Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae) were assessed in laboratory bioassays. Survival and development of C. sinica larvae were not adversely affected when the larvae were fed a diet containing purified Cry1C protein at 200 µg/g fresh weight, representing a worst-case exposure scenario; in contrast, C. sinica larvae were adversely affected when the diet contained avidin or potassium arsenate. Life table parameters of C. sinica adults did not differ when the adults were fed with Bt or non-Bt rice pollen together with a 2-M sucrose solution. Life table parameters of C. sinica adults also did not differ when the adults were fed an artificial diet with or without purified Cry1C protein at a nominal concentration that was approximately 20 times higher than that in rice pollen; in contrast, C. sinica adults were adversely affected when the diet contained potassium arsenate. In all bioassays with lacewings, the bioactivity and stability of the Cry1C protein in the diet and Cry1C protein uptake by the lacewings were confirmed by enzyme-linked immunosorbent assay (ELISA) and by bioassays with a Cry1C-sensitive lepidopteran. These results demonstrate that neither larvae nor adults of C. sinica are sensitive to Cry1C protein at concentrations higher than those encountered in the field, demonstrating that the growing of Bt rice producing Cry1C protein is unlikely to pose a risk to C. sinica.
The green lacewing, Chrysoperla rufilabris (Burmeister), is considered an important natural preda... more The green lacewing, Chrysoperla rufilabris (Burmeister), is considered an important natural predator due to its wide geographic distribution and its voracious larval feeding capacity. Its larvae feed on soft-bodies arthropods in many different crop habitats. Thus, C. rufilabris may be exposed to insecticidal proteins from Bacillus thuringiensis (Bt) when they are expressed in genetically engineered crops. Laboratory experiments were conducted to evaluate the prey-mediated impacts of Bt broccoli (expressing Cry1Ac), Bt cotton (expressing Cry1Ac/Cry2Ab) and Bt maize (expressing Cry1F) on several fitness parameters of C. rufilabris over two generations using Bt-resistant cabbage lopper, Trichoplusia ni, and Bt-resistant fall armyworm, Spodoptera frugiperda (JE Smith), larvae as prey. ELISA and sensitive-insect bioassays confirmed that C. rufilabris were exposed to bioactive Bt proteins. Development time of larval and pupal stages, female fecundity and egg hatching rate of C. rufilabris...
Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae) is a solitary, larval endoparasitoid, ... more Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae) is a solitary, larval endoparasitoid, and important natural enemy of noctuid moths. C. marginiventris attacks 1st and 2nd instars and its larvae feed on host hemolymph and tissue and emerge from the host to pupate. Thus, C. marginiventris may be exposed to Bt proteins when their host larvae feed on Bt crops. To eliminate host quality mediated-effects that occur when susceptible hosts fed Bt crops become sub-optimal, we used Bt-resistant fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) larvae as hosts and evaluated the potential impact of Cry1F expressing corn (Mycogen 2A517) on several fitness parameters of C. marginiventris over three generations. Survival, parasitism, development time of larval and pupal stages, adult longevity and offspring sex ratio of C. marginiventris were observed. Our results demonstrated there were no differences when resistant S. frugiperda larvae reared on either Bt or control...
The ladybird beetle, Coleomegilla maculata (DeGeer), is a common and abundant predator that suppr... more The ladybird beetle, Coleomegilla maculata (DeGeer), is a common and abundant predator that suppresses pest populations in many cropping systems. Its larvae and adults are polyphagous, feeding on aphids, thrips, lepidopteran eggs and larvae as well as plant tissues. Thus, C. maculata may be exposed by several means to insecticidal proteins expressed in genetically engineered crops expressing insecticidal proteins from Bacillus thuringiensis (Bt). We evaluated the potential impact of Cry1F expressing corn (Mycogen 2A517) on several fitness parameters of C. maculata over two generations using Bt-resistant Spodoptera frugiperda (JE Smith) larvae as prey. Survival, duration of larval and pupal stages, adult weight and female fecundity of C. maculata were not different when they were fed resistant S. frugiperda larvae reared on either Bt or control corn leaves for both generations. ELISA and sensitive-insect bioassays showed C. maculata were exposed to bioactive Cry1F protein. However, t...
Ecosystem functioning might be affected by cultivation of genetically engineered (GE) plants thro... more Ecosystem functioning might be affected by cultivation of genetically engineered (GE) plants through effects on non-target organisms contributing to important ecosystem services. The number of commercialized transgenic events and the cultivation areas are steadily increasing worldwide. Therefore, the careful execution of ecological risk assessments for new GE plants is crucial. Until now, only few studies assessed the potentially adverse effects of GE crops on the survival and fitness of dipteran species. This, despite the fact that Diptera play important roles in the agricultural ecosystem as predators, parasitoids, pollinators and decomposers. We propose Drosophila melanogaster Meigen 1830 (Drosophilidae) to be tested in the pre-market risk assessment as a surrogate species for the order of Diptera. We are developing two different study systems for this species to assess toxicity of insecticidal proteins and GE plant tissues. This involves the development of skills and experience ...
The bigeyed bug, Geocoris punctipes, is an abundant predator in many cropping systems. Its nymphs... more The bigeyed bug, Geocoris punctipes, is an abundant predator in many cropping systems. Its nymphs and adults are active predators that attack a wide variety of pests, including aphids, soft-bodied insect larvae, and insect eggs in cotton, soybean and other crops. Thus, G. punctipes may be exposed by multiple routes to insecticidal proteins expressed in genetically engineered crops producing insecticidal proteins from Bacillus thuringiensis (Bt). We evaluated the potential impact of Cry1Ac and Cry2Ab expressing cotton (BollGard II) on several fitness parameters of G. punctipes over two generations using Bt-resistant Trichoplusia ni larvae as prey. Duration of the nymphal stage, adult weight, female fecundity and egg hatching rate of G. punctipes were not different when they were fed resistant T. ni larvae reared on either Bt or control cotton leaves for both generations. Our results demonstrate that Cry1Ac and Cry2Ab expressing cotton does not affect important fitness parameters of G...
We compared the longevity of the aphid parasitoid Aphidius ervi fed on honeydew from Aulacorthum ... more We compared the longevity of the aphid parasitoid Aphidius ervi fed on honeydew from Aulacorthum solani, Macrosiphum euphorbiae, and Myzus persicae on potato. As controls, separate parasitoid cohorts were provided with a sucrose solution or water only. All honeydews studied were found to enhance parasitoid longevity as much as the sucrose solution. HPLC analysis of the honeydews showed little differences
Journal of agricultural and food chemistry, Jan 18, 2015
The honey bee, Apis mellifera, is commonly used as a test species for the regulatory risk assessm... more The honey bee, Apis mellifera, is commonly used as a test species for the regulatory risk assessment of insect-resistant genetically engineered (IRGE) plants. In the current study, a dietary exposure assay was developed, validated, and used to assess the potential toxicity of Cry1C and Cry2A proteins from Bacillus thuringiensis (Bt) to A. mellifera larvae; Cry1C and Cry2A are produced by different IRGE crops. The assay, which uses the soybean trypsin inhibitor (SBTI) as a positive control and bovine serum albumin (BSA) as a negative control, was used to measure the responses of A. mellifera larvae to high concentrations of Cry1C and Cry2A. Survival was reduced and development was delayed when larvae were fed SBTI (1 mg/g diet) but were unaffected when larvae were fed BSA (400 µg/g), Cry1C (50 µg/g), or Cry2A (400 µg/g). The enzymatic activities of A. mellifera larvae were not altered and their midgut brush border membranes (BBMs) were not damaged after being fed with diets containin...
The effects of insect-resistant genetically engineered rice producing Cry1C protein derived from ... more The effects of insect-resistant genetically engineered rice producing Cry1C protein derived from Bacillus thuringiensis (Bt) on Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae) were assessed in laboratory bioassays. Survival and development of C. sinica larvae were not adversely affected when the larvae were fed a diet containing purified Cry1C protein at 200 µg/g fresh weight, representing a worst-case exposure scenario; in contrast, C. sinica larvae were adversely affected when the diet contained avidin or potassium arsenate. Life table parameters of C. sinica adults did not differ when the adults were fed with Bt or non-Bt rice pollen together with a 2-M sucrose solution. Life table parameters of C. sinica adults also did not differ when the adults were fed an artificial diet with or without purified Cry1C protein at a nominal concentration that was approximately 20 times higher than that in rice pollen; in contrast, C. sinica adults were adversely affected when the diet contained potassium arsenate. In all bioassays with lacewings, the bioactivity and stability of the Cry1C protein in the diet and Cry1C protein uptake by the lacewings were confirmed by enzyme-linked immunosorbent assay (ELISA) and by bioassays with a Cry1C-sensitive lepidopteran. These results demonstrate that neither larvae nor adults of C. sinica are sensitive to Cry1C protein at concentrations higher than those encountered in the field, demonstrating that the growing of Bt rice producing Cry1C protein is unlikely to pose a risk to C. sinica.
The green lacewing, Chrysoperla rufilabris (Burmeister), is considered an important natural preda... more The green lacewing, Chrysoperla rufilabris (Burmeister), is considered an important natural predator due to its wide geographic distribution and its voracious larval feeding capacity. Its larvae feed on soft-bodies arthropods in many different crop habitats. Thus, C. rufilabris may be exposed to insecticidal proteins from Bacillus thuringiensis (Bt) when they are expressed in genetically engineered crops. Laboratory experiments were conducted to evaluate the prey-mediated impacts of Bt broccoli (expressing Cry1Ac), Bt cotton (expressing Cry1Ac/Cry2Ab) and Bt maize (expressing Cry1F) on several fitness parameters of C. rufilabris over two generations using Bt-resistant cabbage lopper, Trichoplusia ni, and Bt-resistant fall armyworm, Spodoptera frugiperda (JE Smith), larvae as prey. ELISA and sensitive-insect bioassays confirmed that C. rufilabris were exposed to bioactive Bt proteins. Development time of larval and pupal stages, female fecundity and egg hatching rate of C. rufilabris...
Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae) is a solitary, larval endoparasitoid, ... more Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae) is a solitary, larval endoparasitoid, and important natural enemy of noctuid moths. C. marginiventris attacks 1st and 2nd instars and its larvae feed on host hemolymph and tissue and emerge from the host to pupate. Thus, C. marginiventris may be exposed to Bt proteins when their host larvae feed on Bt crops. To eliminate host quality mediated-effects that occur when susceptible hosts fed Bt crops become sub-optimal, we used Bt-resistant fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) larvae as hosts and evaluated the potential impact of Cry1F expressing corn (Mycogen 2A517) on several fitness parameters of C. marginiventris over three generations. Survival, parasitism, development time of larval and pupal stages, adult longevity and offspring sex ratio of C. marginiventris were observed. Our results demonstrated there were no differences when resistant S. frugiperda larvae reared on either Bt or control...
The ladybird beetle, Coleomegilla maculata (DeGeer), is a common and abundant predator that suppr... more The ladybird beetle, Coleomegilla maculata (DeGeer), is a common and abundant predator that suppresses pest populations in many cropping systems. Its larvae and adults are polyphagous, feeding on aphids, thrips, lepidopteran eggs and larvae as well as plant tissues. Thus, C. maculata may be exposed by several means to insecticidal proteins expressed in genetically engineered crops expressing insecticidal proteins from Bacillus thuringiensis (Bt). We evaluated the potential impact of Cry1F expressing corn (Mycogen 2A517) on several fitness parameters of C. maculata over two generations using Bt-resistant Spodoptera frugiperda (JE Smith) larvae as prey. Survival, duration of larval and pupal stages, adult weight and female fecundity of C. maculata were not different when they were fed resistant S. frugiperda larvae reared on either Bt or control corn leaves for both generations. ELISA and sensitive-insect bioassays showed C. maculata were exposed to bioactive Cry1F protein. However, t...
Ecosystem functioning might be affected by cultivation of genetically engineered (GE) plants thro... more Ecosystem functioning might be affected by cultivation of genetically engineered (GE) plants through effects on non-target organisms contributing to important ecosystem services. The number of commercialized transgenic events and the cultivation areas are steadily increasing worldwide. Therefore, the careful execution of ecological risk assessments for new GE plants is crucial. Until now, only few studies assessed the potentially adverse effects of GE crops on the survival and fitness of dipteran species. This, despite the fact that Diptera play important roles in the agricultural ecosystem as predators, parasitoids, pollinators and decomposers. We propose Drosophila melanogaster Meigen 1830 (Drosophilidae) to be tested in the pre-market risk assessment as a surrogate species for the order of Diptera. We are developing two different study systems for this species to assess toxicity of insecticidal proteins and GE plant tissues. This involves the development of skills and experience ...
The bigeyed bug, Geocoris punctipes, is an abundant predator in many cropping systems. Its nymphs... more The bigeyed bug, Geocoris punctipes, is an abundant predator in many cropping systems. Its nymphs and adults are active predators that attack a wide variety of pests, including aphids, soft-bodied insect larvae, and insect eggs in cotton, soybean and other crops. Thus, G. punctipes may be exposed by multiple routes to insecticidal proteins expressed in genetically engineered crops producing insecticidal proteins from Bacillus thuringiensis (Bt). We evaluated the potential impact of Cry1Ac and Cry2Ab expressing cotton (BollGard II) on several fitness parameters of G. punctipes over two generations using Bt-resistant Trichoplusia ni larvae as prey. Duration of the nymphal stage, adult weight, female fecundity and egg hatching rate of G. punctipes were not different when they were fed resistant T. ni larvae reared on either Bt or control cotton leaves for both generations. Our results demonstrate that Cry1Ac and Cry2Ab expressing cotton does not affect important fitness parameters of G...
We compared the longevity of the aphid parasitoid Aphidius ervi fed on honeydew from Aulacorthum ... more We compared the longevity of the aphid parasitoid Aphidius ervi fed on honeydew from Aulacorthum solani, Macrosiphum euphorbiae, and Myzus persicae on potato. As controls, separate parasitoid cohorts were provided with a sucrose solution or water only. All honeydews studied were found to enhance parasitoid longevity as much as the sucrose solution. HPLC analysis of the honeydews showed little differences
Journal of agricultural and food chemistry, Jan 18, 2015
The honey bee, Apis mellifera, is commonly used as a test species for the regulatory risk assessm... more The honey bee, Apis mellifera, is commonly used as a test species for the regulatory risk assessment of insect-resistant genetically engineered (IRGE) plants. In the current study, a dietary exposure assay was developed, validated, and used to assess the potential toxicity of Cry1C and Cry2A proteins from Bacillus thuringiensis (Bt) to A. mellifera larvae; Cry1C and Cry2A are produced by different IRGE crops. The assay, which uses the soybean trypsin inhibitor (SBTI) as a positive control and bovine serum albumin (BSA) as a negative control, was used to measure the responses of A. mellifera larvae to high concentrations of Cry1C and Cry2A. Survival was reduced and development was delayed when larvae were fed SBTI (1 mg/g diet) but were unaffected when larvae were fed BSA (400 µg/g), Cry1C (50 µg/g), or Cry2A (400 µg/g). The enzymatic activities of A. mellifera larvae were not altered and their midgut brush border membranes (BBMs) were not damaged after being fed with diets containin...
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