Despite their positive effect in reducing pest populations, exotic generalist predators sometimes become invasive and contribute to the displacement of indigenous species in the same trophic level. Although laboratory...Despite their positive effect in reducing pest populations, exotic generalist predators sometimes become invasive and contribute to the displacement of indigenous species in the same trophic level. Although laboratory experiments have linked intraguild predation （IGP） to these interactions, field evidence and quantification of IGP are still lacking for most systems. The recent establishment of the exotic Harmonia axyridis （Pallas） （Coleoptera： Coccinellidae） in Italy raises concern about the detrimental effect that the ladybird could have on native coccinellids. Here we assessed, under laboratory conditions, the acceptability and suitability of eggs of 2 native ladybirds, Adalia bipunctata L. and Oenopia conglobata （L.）, as prey items for H. axyridis larvae. Then we developed primers for molecular gut-content analysis to detect predation by H. axyridis on the 2 ladybirds and on the aphid Eucallipterus tiliae L. Species-specific 16S primers were developed for the 3 species and laboratory feeding trials were conducted to quantify the rate of prey DNA breakdown in the gut of//. axyridis. Moreover, to field evaluate primers, H. axyridis 4th instars （n = 132） were systematically collected from linden trees in northern Italy and screened for the presence of prey DNA. Seventy-three percent and 7% of field collected H. axyridis were positive for aphid and coccinellid DNA, respectively. Predation upon aphid and A. bipunctata was lower than predicted if density dependent consumption was expected, while predation upon O. conglobata was significantly higher. Here, we provided the first evidence of IGP among feral populations ofH. axyridis and indigenous ladybird beetles, occurring in Italy.展开更多
It is thought that there are many unregulated anthropogenic chemicals in the environment.For risk assessment of chemicals, it is essential to estimate the predicted environmental concentrations. As an effort of identi...It is thought that there are many unregulated anthropogenic chemicals in the environment.For risk assessment of chemicals, it is essential to estimate the predicted environmental concentrations. As an effort of identifying residual organic contaminants in air and water in Korea, nontarget screening using two-dimensional gas chromatography time-of-flight mass spectrometry（GC × GC-TOFMS） was conducted at 10 sites using polyurethane foam passive air sampler and at 6 sites using polydimethyl siloxane（PDMS） passive water sampler in three different seasons in 2014. More than 600 chemical peaks were identified satisfying the identification criteria in air and water samples, respectively, providing a list for further investigation. Chemical substances with reported national emission rates in2014（n = 149） were also screened for potential existence in the environment using a level Ⅱ fugacity model. Most of chemical substances classified as not detectable were not identified with detection frequency greater than 20% by nontarget screening, indicating that a simple equilibrium model has a strong potential to be used to exclude chemicals that are not likely to remain in the environment after emissions from targeted monitoring.展开更多
RNA interference(RNAi)has emerged as a powerful tool for developing novel management strategies for controlling insect pests.The 28-spotted ladybeetle,Henosepilachna vigintioctopunctata is one of the most important pe...RNA interference(RNAi)has emerged as a powerful tool for developing novel management strategies for controlling insect pests.The 28-spotted ladybeetle,Henosepilachna vigintioctopunctata is one of the most important pests attacking solanaceous plants in Asia.In this study,the potential of dietary RNAi to manage H.vigintioctopunctata was investigated using both in vitro synthesized and bacterially expressed double-stranded RNAs(dsRNAs)of HvvATPase A and HvvATPase E.The expression levels of HvvATPase A and HvvATPase E were higher in Malpighian tubules than in other tissue types.The silencing of HvvATPase A and HvvATPase E led to significant mortality in H.vigintioctopunctata larvae.In addition,the ingestion of HvvATPase A and HvvATPase E significantly deterred feeding behavior and subsequently arrested the development of H.vigintioctopunctata.Notably,the bacterially expressed dsRNAs consistently caused higher mortality in larvae and adults.Finally,the nontarget effects of the dsRNAs of H.vigintioctopunctata on the predatory ladybeetle Propylaea japonica were evaluated.P.japonica 1st instar larvae were administered vATPase A and vATPase E dsRNAs from H.vigintioctopunctata and P.japonica under the worst-case scenario,in which dsGFP served as negative control.There were significant effects of dsHvvATPase A on P.japonica at the transcriptional level but not at the organismal level,whereas dsHvvATPase E did not effect P.japonica at either the transcriptional or the organismal level.Collectively,the results of the study suggest that HvvATPase A and HvvATPase E can act as novel molecular targets for the control of H.vigintioctopunctata.展开更多
Environmental impacts of genetically modified crops are mandatorily assessed during their premarket phase. One of the areas of concern is the possible impact on nontar- get organisms. Crops expressing Cry toxins might...Environmental impacts of genetically modified crops are mandatorily assessed during their premarket phase. One of the areas of concern is the possible impact on nontar- get organisms. Crops expressing Cry toxins might affect Lepidoptera larvae living outside cultivated fields, through pollen deposition on wild plants, which constitute their food source. While pollen toxicity varies among different events, possible exposure ofnontarget species depends on the agro-environmental conditions. This study was conducted in two protected areas in Italy, characterized by different climatic conditions, where many Lepi- doptera species thrive in proximity to maize cultivations. To estimate the possible exposure in absence of the actual stressor （e.g., Cryl-expressing maize plants）, we conducted a two-year field survey of butterflies and weeds. Indicator species were selected--Aglais （Inachis） io in the Northern site and Vanessa cardui in the Southern site--and their phe- nology was investigated. Pollen dispersal from maize fields was measured by collection in Petri dishes. Duration and frequency of exposure was defined by the overlap between pollen emission and presence of larvae on host plants. Different risk scenarios are expected in the two regions： highest exposure is foreseen forA. io in the Northern site, while minimal exposure is estimated for V. cardui in the Southern site. In the latter case, locally grown maize cultivars flower in mid-summer in coincidence with an aestivation period for several butterfly species due to hot and dry conditions. Moreover, host plants of V. cardui are at the end of their life cycle thus limiting food availability.展开更多
In the present study, the herbicidal effects of two fungicides with the active ingredients expoxiconazole, fluxapyroxad, pyraclostrobin and fenpropimorph on the two arable weeds Lamium purpureum L. and Chenopodium alb...In the present study, the herbicidal effects of two fungicides with the active ingredients expoxiconazole, fluxapyroxad, pyraclostrobin and fenpropimorph on the two arable weeds Lamium purpureum L. and Chenopodium album L. were investigated. The experiments were conducted in a climate chamber under defined conditions. Sowing pods were prepared and plants at the cotyledon leaf stage were pricked out in test pods. Fungicides were applied at six application rates: 0%, 12.5%, 25%, 50%, 100% and 200% of the maximum registered dose rate in Germany. Seven days after application, the first assessment was conducted, regarding growth stage, quantity of plants and visible plant damage. Fourteen days after application, the second and final assessment was conducted, regarding growth stage, quantity of plants, visible plant damage and the fresh weight of the plants. There were herbicidal effects of the fungicides, which were presumably due to the active ingredient epoxiconazole. Epoxiconazole has effects on enzymes that are dependent on cytochrome P-450 and inhibits sterol biosynthesis and probably gibberellin synthesis. By doing so, these fungicides have similar effects to plant growth regulators. Weed species showed differential sensitivities, contractions and growth inhibition and ED50-values were calculated. Notwithstanding the probably minor relevance of the present results in agricultural practice, some effects on arable weeds might result if fungicides are applied at an early growth stage in the field. In some cases, the crop-weed competition could be shifted to the benefit of the crop. Nevertheless, the results are interesting for the field of weed research and for the assessment of the ecotoxicology of fungicides.展开更多
Although disinfection byproducts(DBPs) in drinking water have been suggested as a cancer causing factor, the causative compounds have not yet been clarified. In this study, we used liquid chromatography quadrupole-tim...Although disinfection byproducts(DBPs) in drinking water have been suggested as a cancer causing factor, the causative compounds have not yet been clarified. In this study, we used liquid chromatography quadrupole-time-of-flight spectrometry(LC-QTOF MS) to identify the unknown disinfection byproducts(DBPs) in drinking water produced from Taihu Lake source water, which is known as a convergence point for the anthropogenic pollutants discharged from intensive industrial activities in the surrounding regions. In total, 91 formulas of DBPs were discovered through LC-QTOF MS nontarget screen, 81 of which have not yet been reported. Among the 91 molecules, 56 only contain bromine, 15 only contain chlorine and 20 DBPs have both bromine and chlorine atoms. Finally, five DBPs including 2,4,6-tribromophenol, 2,6-dibromo-4-chlorophenol, 2,6-dichloro-4-bromophenol, 4-bromo-2,6-di-tert-butylphenol and 3,6-dibromocarbazole were confirmed using standards. The former three compounds mainly formed in the predisinfection step(maximum concentration, 0.2-2.6 μg/L), while the latter two formed in the disinfection step(maximum concentration, 18.2-33.6 ng/L). In addition, 19 possible precursors of the discovered DBPs were detected, with the aromatic compounds being a major group. 2,6-di-tert-butylphenol as the precursor of 4-bromo-2,6-di-tert-butylphenol was confirmed with standard, with a concentration of 20.3 μg/L in raw water. The results of this study show that brominated DBPs which are possibly formed from industrial pollutants are relevant DBP species in drinking water produced form Taihu source water, suggesting protection of Taihu Lake source water is important to control the DBP risks.展开更多
Fungicides are used to control pathogenic fungi of crop species,but they have also been shown to alter behavioral,life history and fitness related traits of nontarget insects.Here,we tested the fungicide effects on fe...Fungicides are used to control pathogenic fungi of crop species,but they have also been shown to alter behavioral,life history and fitness related traits of nontarget insects.Here,we tested the fungicide effects on feeding behavior,survival and physiology of the nontarget pest insect,the Colorado potato beetle(CPB)(Leptinotarsa decemlineata).Feeding behavior was studied by a choice test of adult beetles,which were allowed to choose between a control and a fungicide(fluazinam)treated potato leaf.Larval survival was recorded after 24 and 72 h exposure to control and fungicide-treated leaves with 2 different concentrations.The adults did not show fungicide avoidance behavior.Similarly,survival of the larvae was not affected by the exposure to fungicides.Finally,to understand the effects of fungicides at the physiological level(gene expression),we tested whether the larval exposure to fungicide alter the expression of 5 metabolic pathway and stress associated genes.Highest concentration and 72-h exposure caused upregulation of 1 cytochrome P450(CYP9Z14v2)and 1 insecticide resistance gene(Ldace1),whereas metabolic detoxification gene(Ugt1)was downregulated.At 24-h exposure,highest concentration caused downregulation of another common detoxification gene(Gs),while both exposure times to lowest concentration caused upregulation of the Hsp70 stress tolerance gene.Despite these overall effects,there was a considerable amount of variation among different families in the gene expression levels.Even though the behavioral effects of the fungicide treatments were minor,the expression level differences of the studied genes indicate changes on the metabolic detoxifications and stress-related pathways.展开更多
American chestnut(Castanea dentata[Marsh.]Borkh.)was once the dominant hardwood species in Eastern North America before an exotic fungal pathogen,Cryphonec-tria parasitica(Murrill)Barr,functionally eliminated it acros...American chestnut(Castanea dentata[Marsh.]Borkh.)was once the dominant hardwood species in Eastern North America before an exotic fungal pathogen,Cryphonec-tria parasitica(Murrill)Barr,functionally eliminated it across its range.One promising approach toward restoring American chestnut to natural forests is development of blight-tolerant trees using genetic transformation.However,transformation and related processes can result in unexpected and unintended phenotypic changes,potentially altering ecologi-cal interactions.To assess unintended tritrophic impacts of transgenic American chestnut on plant herbivore interactions,gypsy moth(Lymantria dispar L.)caterpillars were fed leaf disks excised from two transgenic events,Darling 54 and Darling 58,and four control American chestnut lines.Leaf disks were previously treated with an LDso dose of either the speces-specific Lymantria dispar multiple nucleopolyhedrovirus(LdMNPV)or the generalist pathogen Bacillus thuringiensis subsp.kurstaki(Btk).Mortality was quantified and compared to water blank controls.Tree genotype had a strong efect on the efficacies of both pathogens.Larval mortality from Btk-treated foliage from only one transgenic event,Darling 54,differed from its isogenic progenitor,Ellis l,but was similar to an unre-lated wild-type American chestnut control.LdMNPV efficacy was unaffected by genetic transformation.Results suggest that although genetic modification of trees may affect interactions with other nontarget organisms,this may be due to insertion effects,and varia-tion amnon diMterent genvtypes(wlether uasgeic ul wild-typc)iupaults a giealci change in response than transgene presence.展开更多
建立了固相吸附热脱附-气相色谱-质谱(TD-GC-MS)综合筛查工业源废气中挥发性有机物(VOCs)的方法。对两种型号的固相吸附管进行了比较,最终选择使用Tenax SS TD Tubes吸附管。气体样品以恒定流速通过吸附管,富集分析物,经热脱附后,用GC-M...建立了固相吸附热脱附-气相色谱-质谱(TD-GC-MS)综合筛查工业源废气中挥发性有机物(VOCs)的方法。对两种型号的固相吸附管进行了比较,最终选择使用Tenax SS TD Tubes吸附管。气体样品以恒定流速通过吸附管,富集分析物,经热脱附后,用GC-MS进行检测,目标化合物以内标法定量,非目标化合物的含量以甲苯的响应系数计算。方法检出限为1.06~5.44 ng,以采样体积300 mL计算,目标化合物的检出限为0.004~0.018 mg/m^3。吸附管平均加标回收率为78.4%~89.4%,相对标准偏差为3.9%~14.4%(n=7)。应用该方法对大连市某垃圾焚烧发电厂排放的废气进行VOCs目标及非目标化合物综合筛查,共检出29种VOCs,其中仅5种VOCs为预先设定的目标化合物,另外24种为非目标化合物,5种目标化合物含量仅占所有检出物总量的26.7%。证明了工业源废气VOCs分析中非目标化合物筛查的重要性,该研究思路对完整测定工业源挥发性有机污染物分布具有一定的借鉴意义。展开更多
文摘Despite their positive effect in reducing pest populations, exotic generalist predators sometimes become invasive and contribute to the displacement of indigenous species in the same trophic level. Although laboratory experiments have linked intraguild predation （IGP） to these interactions, field evidence and quantification of IGP are still lacking for most systems. The recent establishment of the exotic Harmonia axyridis （Pallas） （Coleoptera： Coccinellidae） in Italy raises concern about the detrimental effect that the ladybird could have on native coccinellids. Here we assessed, under laboratory conditions, the acceptability and suitability of eggs of 2 native ladybirds, Adalia bipunctata L. and Oenopia conglobata （L.）, as prey items for H. axyridis larvae. Then we developed primers for molecular gut-content analysis to detect predation by H. axyridis on the 2 ladybirds and on the aphid Eucallipterus tiliae L. Species-specific 16S primers were developed for the 3 species and laboratory feeding trials were conducted to quantify the rate of prey DNA breakdown in the gut of//. axyridis. Moreover, to field evaluate primers, H. axyridis 4th instars （n = 132） were systematically collected from linden trees in northern Italy and screened for the presence of prey DNA. Seventy-three percent and 7% of field collected H. axyridis were positive for aphid and coccinellid DNA, respectively. Predation upon aphid and A. bipunctata was lower than predicted if density dependent consumption was expected, while predation upon O. conglobata was significantly higher. Here, we provided the first evidence of IGP among feral populations ofH. axyridis and indigenous ladybird beetles, occurring in Italy.
基金supported by the National Institute of Environmental Research(No.NIER-RP-2014-335)
文摘It is thought that there are many unregulated anthropogenic chemicals in the environment.For risk assessment of chemicals, it is essential to estimate the predicted environmental concentrations. As an effort of identifying residual organic contaminants in air and water in Korea, nontarget screening using two-dimensional gas chromatography time-of-flight mass spectrometry（GC × GC-TOFMS） was conducted at 10 sites using polyurethane foam passive air sampler and at 6 sites using polydimethyl siloxane（PDMS） passive water sampler in three different seasons in 2014. More than 600 chemical peaks were identified satisfying the identification criteria in air and water samples, respectively, providing a list for further investigation. Chemical substances with reported national emission rates in2014（n = 149） were also screened for potential existence in the environment using a level Ⅱ fugacity model. Most of chemical substances classified as not detectable were not identified with detection frequency greater than 20% by nontarget screening, indicating that a simple equilibrium model has a strong potential to be used to exclude chemicals that are not likely to remain in the environment after emissions from targeted monitoring.
基金supported by the National Key R&D Program of China(2017YFD0200900)National Natural Science Foundation of China(31972269)GDUPS(2017).
文摘RNA interference(RNAi)has emerged as a powerful tool for developing novel management strategies for controlling insect pests.The 28-spotted ladybeetle,Henosepilachna vigintioctopunctata is one of the most important pests attacking solanaceous plants in Asia.In this study,the potential of dietary RNAi to manage H.vigintioctopunctata was investigated using both in vitro synthesized and bacterially expressed double-stranded RNAs(dsRNAs)of HvvATPase A and HvvATPase E.The expression levels of HvvATPase A and HvvATPase E were higher in Malpighian tubules than in other tissue types.The silencing of HvvATPase A and HvvATPase E led to significant mortality in H.vigintioctopunctata larvae.In addition,the ingestion of HvvATPase A and HvvATPase E significantly deterred feeding behavior and subsequently arrested the development of H.vigintioctopunctata.Notably,the bacterially expressed dsRNAs consistently caused higher mortality in larvae and adults.Finally,the nontarget effects of the dsRNAs of H.vigintioctopunctata on the predatory ladybeetle Propylaea japonica were evaluated.P.japonica 1st instar larvae were administered vATPase A and vATPase E dsRNAs from H.vigintioctopunctata and P.japonica under the worst-case scenario,in which dsGFP served as negative control.There were significant effects of dsHvvATPase A on P.japonica at the transcriptional level but not at the organismal level,whereas dsHvvATPase E did not effect P.japonica at either the transcriptional or the organismal level.Collectively,the results of the study suggest that HvvATPase A and HvvATPase E can act as novel molecular targets for the control of H.vigintioctopunctata.
文摘Environmental impacts of genetically modified crops are mandatorily assessed during their premarket phase. One of the areas of concern is the possible impact on nontar- get organisms. Crops expressing Cry toxins might affect Lepidoptera larvae living outside cultivated fields, through pollen deposition on wild plants, which constitute their food source. While pollen toxicity varies among different events, possible exposure ofnontarget species depends on the agro-environmental conditions. This study was conducted in two protected areas in Italy, characterized by different climatic conditions, where many Lepi- doptera species thrive in proximity to maize cultivations. To estimate the possible exposure in absence of the actual stressor （e.g., Cryl-expressing maize plants）, we conducted a two-year field survey of butterflies and weeds. Indicator species were selected--Aglais （Inachis） io in the Northern site and Vanessa cardui in the Southern site--and their phe- nology was investigated. Pollen dispersal from maize fields was measured by collection in Petri dishes. Duration and frequency of exposure was defined by the overlap between pollen emission and presence of larvae on host plants. Different risk scenarios are expected in the two regions： highest exposure is foreseen forA. io in the Northern site, while minimal exposure is estimated for V. cardui in the Southern site. In the latter case, locally grown maize cultivars flower in mid-summer in coincidence with an aestivation period for several butterfly species due to hot and dry conditions. Moreover, host plants of V. cardui are at the end of their life cycle thus limiting food availability.
文摘In the present study, the herbicidal effects of two fungicides with the active ingredients expoxiconazole, fluxapyroxad, pyraclostrobin and fenpropimorph on the two arable weeds Lamium purpureum L. and Chenopodium album L. were investigated. The experiments were conducted in a climate chamber under defined conditions. Sowing pods were prepared and plants at the cotyledon leaf stage were pricked out in test pods. Fungicides were applied at six application rates: 0%, 12.5%, 25%, 50%, 100% and 200% of the maximum registered dose rate in Germany. Seven days after application, the first assessment was conducted, regarding growth stage, quantity of plants and visible plant damage. Fourteen days after application, the second and final assessment was conducted, regarding growth stage, quantity of plants, visible plant damage and the fresh weight of the plants. There were herbicidal effects of the fungicides, which were presumably due to the active ingredient epoxiconazole. Epoxiconazole has effects on enzymes that are dependent on cytochrome P-450 and inhibits sterol biosynthesis and probably gibberellin synthesis. By doing so, these fungicides have similar effects to plant growth regulators. Weed species showed differential sensitivities, contractions and growth inhibition and ED50-values were calculated. Notwithstanding the probably minor relevance of the present results in agricultural practice, some effects on arable weeds might result if fungicides are applied at an early growth stage in the field. In some cases, the crop-weed competition could be shifted to the benefit of the crop. Nevertheless, the results are interesting for the field of weed research and for the assessment of the ecotoxicology of fungicides.
基金This work was supported by Major Science and Technology Program for Water Pollution Control and Treatment(No.2017ZX07502003)the National Key R&D Program of China(No.2018YFE0204101).
文摘Although disinfection byproducts(DBPs) in drinking water have been suggested as a cancer causing factor, the causative compounds have not yet been clarified. In this study, we used liquid chromatography quadrupole-time-of-flight spectrometry(LC-QTOF MS) to identify the unknown disinfection byproducts(DBPs) in drinking water produced from Taihu Lake source water, which is known as a convergence point for the anthropogenic pollutants discharged from intensive industrial activities in the surrounding regions. In total, 91 formulas of DBPs were discovered through LC-QTOF MS nontarget screen, 81 of which have not yet been reported. Among the 91 molecules, 56 only contain bromine, 15 only contain chlorine and 20 DBPs have both bromine and chlorine atoms. Finally, five DBPs including 2,4,6-tribromophenol, 2,6-dibromo-4-chlorophenol, 2,6-dichloro-4-bromophenol, 4-bromo-2,6-di-tert-butylphenol and 3,6-dibromocarbazole were confirmed using standards. The former three compounds mainly formed in the predisinfection step(maximum concentration, 0.2-2.6 μg/L), while the latter two formed in the disinfection step(maximum concentration, 18.2-33.6 ng/L). In addition, 19 possible precursors of the discovered DBPs were detected, with the aromatic compounds being a major group. 2,6-di-tert-butylphenol as the precursor of 4-bromo-2,6-di-tert-butylphenol was confirmed with standard, with a concentration of 20.3 μg/L in raw water. The results of this study show that brominated DBPs which are possibly formed from industrial pollutants are relevant DBP species in drinking water produced form Taihu source water, suggesting protection of Taihu Lake source water is important to control the DBP risks.
基金supported by the Finish Cultural foundation and the Academy of Finland(Grant NO.308302 to LL and 322980 to MK).
文摘Fungicides are used to control pathogenic fungi of crop species,but they have also been shown to alter behavioral,life history and fitness related traits of nontarget insects.Here,we tested the fungicide effects on feeding behavior,survival and physiology of the nontarget pest insect,the Colorado potato beetle(CPB)(Leptinotarsa decemlineata).Feeding behavior was studied by a choice test of adult beetles,which were allowed to choose between a control and a fungicide(fluazinam)treated potato leaf.Larval survival was recorded after 24 and 72 h exposure to control and fungicide-treated leaves with 2 different concentrations.The adults did not show fungicide avoidance behavior.Similarly,survival of the larvae was not affected by the exposure to fungicides.Finally,to understand the effects of fungicides at the physiological level(gene expression),we tested whether the larval exposure to fungicide alter the expression of 5 metabolic pathway and stress associated genes.Highest concentration and 72-h exposure caused upregulation of 1 cytochrome P450(CYP9Z14v2)and 1 insecticide resistance gene(Ldace1),whereas metabolic detoxification gene(Ugt1)was downregulated.At 24-h exposure,highest concentration caused downregulation of another common detoxification gene(Gs),while both exposure times to lowest concentration caused upregulation of the Hsp70 stress tolerance gene.Despite these overall effects,there was a considerable amount of variation among different families in the gene expression levels.Even though the behavioral effects of the fungicide treatments were minor,the expression level differences of the studied genes indicate changes on the metabolic detoxifications and stress-related pathways.
基金Thanks to Hannah Nadel(USDA-APHIS)for kindly providing gypsy moth larvae,and John Podgwaite(USDA Forest Service)for providing purified LdM-NPV.We gratefully acknowledge Seaira Goetz and Elliot Hunsinger for their outstanding technical assistance in the laboratory.Substantive comments by T.Horton and M.K.Fierke improved earlier versions of the manuscript.This project was supported by Biotechnology Risk Assessment Grant Program competitive grant No.2012-33522-19863 from the USDA National Institute of Food and.Agriculture.
文摘American chestnut(Castanea dentata[Marsh.]Borkh.)was once the dominant hardwood species in Eastern North America before an exotic fungal pathogen,Cryphonec-tria parasitica(Murrill)Barr,functionally eliminated it across its range.One promising approach toward restoring American chestnut to natural forests is development of blight-tolerant trees using genetic transformation.However,transformation and related processes can result in unexpected and unintended phenotypic changes,potentially altering ecologi-cal interactions.To assess unintended tritrophic impacts of transgenic American chestnut on plant herbivore interactions,gypsy moth(Lymantria dispar L.)caterpillars were fed leaf disks excised from two transgenic events,Darling 54 and Darling 58,and four control American chestnut lines.Leaf disks were previously treated with an LDso dose of either the speces-specific Lymantria dispar multiple nucleopolyhedrovirus(LdMNPV)or the generalist pathogen Bacillus thuringiensis subsp.kurstaki(Btk).Mortality was quantified and compared to water blank controls.Tree genotype had a strong efect on the efficacies of both pathogens.Larval mortality from Btk-treated foliage from only one transgenic event,Darling 54,differed from its isogenic progenitor,Ellis l,but was similar to an unre-lated wild-type American chestnut control.LdMNPV efficacy was unaffected by genetic transformation.Results suggest that although genetic modification of trees may affect interactions with other nontarget organisms,this may be due to insertion effects,and varia-tion amnon diMterent genvtypes(wlether uasgeic ul wild-typc)iupaults a giealci change in response than transgene presence.
