Chrysoperla externa is found in environment, their populations may experience several Brazilian agroecosystems and feeds on many agricultural pests. In each different environmental pressures that can favor the emergen...Chrysoperla externa is found in environment, their populations may experience several Brazilian agroecosystems and feeds on many agricultural pests. In each different environmental pressures that can favor the emergence of genetic mutations and interfere in insect＇s ecological plasticity. Such genetic phenomena can be observed through the use of molecular markers, in particular mitochondrial genes, which are easy to handle and extract. The aim of this work was to study haplotype diversity of Chrysoperla externa in the cities of Jaboticabal （SP）, Brotas （SP）, Rifaina （SP）, Sao Carlos （SP）, Sao Jose dos Campos （SP） and Sao Sebastiao do Paraiso （MG）, and evaluate the degree of genetic differentiation between these populations. Two mitochondrial genes were sequenced to compare these populations. It was found that there were eight haplotypes, six mutations for cytochrome c oxidase subunit 1 （COl） gene and a greater haplotype diversity was found in Brotas and Sao Sebastiao do Paraiso. There were four mutations and six haplotypes for 16S gene and the highest haplotype diversity was found in the city of San Sebastiao do Paraiso. No pattern of haplotype distribution for the populations analyzed was found. The genetic distance between populations of C. externa was not significant, showing that they are genetically compatible.展开更多
Insulin-like peptides(ILPs)act as crucial reproductive neuropeptides in insects,regulating insect reproduction through the insulin signaling pathway(ISP).Our previous studies have found that the sublethal concentratio...Insulin-like peptides(ILPs)act as crucial reproductive neuropeptides in insects,regulating insect reproduction through the insulin signaling pathway(ISP).Our previous studies have found that the sublethal concentrations(LC1 and LC10)of lambda-cyhalothrin(λCy)could induce severe reproductive toxicity in the lacewing,Chrysoperla sinica(Tjeder),but the toxicological mechanism remains unclear.This study discovered thatλCy could inhibit CsILP transcription,leading to a decrease in insulin content and downregulation of C.sinica insulin receptor(CsInR)and C.sinica forkhead box O(CsFOXO)expression in ISP.Interference with CsILP expression resulted in downregulation of C.sinica vitellogenin(CsVg)and decreasing fecundity,while exogenous injection of bovine insulin promoted upregulation of CsVg expression and facilitated reproduction in female adults of C.sinica.Meanwhile,interference with FOXO of ILP downstream transcription factor could lead to downregulation of CsVg,hindering ovarian development and resulting in a decrease in egg production.However,exogenous injection of bovine insulin could remedy the effects caused by FOXO interference.In addition,ILP mediates juvenile hormone and 20-hydroxyecdysone biosynthesis by acting on their synthetic regulatory enzymes and influences the signal transduction of the 2 reproductive endocrine hormones,thereby regulating the reproductive endocrine environment in C.sinica.In conclusion,λCy inhibits CsILP expression,leading to disorder of ISP,leading to the reduced fecundity of C.sinica.展开更多
The comprehensive knowledge that the delayed systemic and reproduction side effects can be even more deleterious than acute toxicity, has caused a shift in focus toward sublethal effects assessment on physiology and b...The comprehensive knowledge that the delayed systemic and reproduction side effects can be even more deleterious than acute toxicity, has caused a shift in focus toward sublethal effects assessment on physiology and behavior of beneficial insects. In this study, we assessed the risks posed by some insecticides with different mode of action through lethal and delayed systemic sublethal effects on the pupation, adult emergence, and repro- duction of the chrysopid Chrysoperla externa （Hagen, 1861; Neuroptera： Chrysopidae）, an important predator in pest biological control. The maximum field recommended dose （MFRD） and twice （2xMFRD） for chlorantraniliprole, tebufenozide, and pyriproxyfen were harmless to C. externa. In contrast, all the tested chitin synthesis inhibitors （CSIs） were highly detrimental to the predator, despite of their lack of acute lethal toxicity. There- fore, the safety assumed by using IGRs toward beneficial insects is not valid for chrysopids. Dose-response data showed that although all CSIs have a similar mechanism of action, the relative extent of toxicity may differ （novaluron 〉 lufenuron 〉 teflubenzuron）. For CSIs, the delayed systemic effects became obvious at adult emergence, where the predicted no observable effect dose （NOED） was 1/2 048 of the MFRD for novaluron （0.085 ng/insect）, and 1/256 of the MFRD for both lufenuron （0.25 ng/insect） and teflubenzuron （0.6 ng/insect）. Finally, this work emphasized the significance of performing toxicity risk assessments with an adequate posttreatment period to avoid underestimating the toxicities of insecticides, as the acute lethal toxicity assays may not provide accurate information regarding the long-range effects of hazardous compounds.展开更多
Understanding predator-prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea （Stephens）, ...Understanding predator-prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea （Stephens）, preying upon eggs and first instar larvae of the cotton bollworm, Helicoverpa armigera Hubner. The first and second instar larvae of C. carnea exhibited typeⅡ functional responses against both prey stages. However, the third instar larvae of C. carnea showed a type II functional response to the first instar larvae of H. armigera, but a typeⅢ functional response to the eggs. For the first instar larvae of C. carnea, the attack rate on H. armigera eggs was significantly higher than that on the larvae, whereas the attack rate of the second instar C. carnea on H. armigera larvae was significantly higher than that on the eggs. For the third instar larvae of C. carnea, the attack rate on the larvae was 1.015±0.278/h, and the attack coefficient on the eggs was 0.036 ±0.005. The handling times of the third instar larvae on larvae and eggs were 0.087 ± 0.009 and 0.071 ± 0.001 h, respectively. The highest predation rate was found for the third instar larvae of C. carnea on H. armigera eggs. Results of this study revealed that the larvae of C. carnea, especially the third instar, had a good predation potential in controlling H. armigera eggs and larvae. However, for a comprehensive estimation of the bio- control abilities of C. carnea toward H, armigera, further field-based studies are needed.展开更多
文摘Chrysoperla externa is found in environment, their populations may experience several Brazilian agroecosystems and feeds on many agricultural pests. In each different environmental pressures that can favor the emergence of genetic mutations and interfere in insect＇s ecological plasticity. Such genetic phenomena can be observed through the use of molecular markers, in particular mitochondrial genes, which are easy to handle and extract. The aim of this work was to study haplotype diversity of Chrysoperla externa in the cities of Jaboticabal （SP）, Brotas （SP）, Rifaina （SP）, Sao Carlos （SP）, Sao Jose dos Campos （SP） and Sao Sebastiao do Paraiso （MG）, and evaluate the degree of genetic differentiation between these populations. Two mitochondrial genes were sequenced to compare these populations. It was found that there were eight haplotypes, six mutations for cytochrome c oxidase subunit 1 （COl） gene and a greater haplotype diversity was found in Brotas and Sao Sebastiao do Paraiso. There were four mutations and six haplotypes for 16S gene and the highest haplotype diversity was found in the city of San Sebastiao do Paraiso. No pattern of haplotype distribution for the populations analyzed was found. The genetic distance between populations of C. externa was not significant, showing that they are genetically compatible.
基金supported by the National Natural Science Foundation of China(No.31972295).
文摘Insulin-like peptides(ILPs)act as crucial reproductive neuropeptides in insects,regulating insect reproduction through the insulin signaling pathway(ISP).Our previous studies have found that the sublethal concentrations(LC1 and LC10)of lambda-cyhalothrin(λCy)could induce severe reproductive toxicity in the lacewing,Chrysoperla sinica(Tjeder),but the toxicological mechanism remains unclear.This study discovered thatλCy could inhibit CsILP transcription,leading to a decrease in insulin content and downregulation of C.sinica insulin receptor(CsInR)and C.sinica forkhead box O(CsFOXO)expression in ISP.Interference with CsILP expression resulted in downregulation of C.sinica vitellogenin(CsVg)and decreasing fecundity,while exogenous injection of bovine insulin promoted upregulation of CsVg expression and facilitated reproduction in female adults of C.sinica.Meanwhile,interference with FOXO of ILP downstream transcription factor could lead to downregulation of CsVg,hindering ovarian development and resulting in a decrease in egg production.However,exogenous injection of bovine insulin could remedy the effects caused by FOXO interference.In addition,ILP mediates juvenile hormone and 20-hydroxyecdysone biosynthesis by acting on their synthetic regulatory enzymes and influences the signal transduction of the 2 reproductive endocrine hormones,thereby regulating the reproductive endocrine environment in C.sinica.In conclusion,λCy inhibits CsILP expression,leading to disorder of ISP,leading to the reduced fecundity of C.sinica.
文摘The comprehensive knowledge that the delayed systemic and reproduction side effects can be even more deleterious than acute toxicity, has caused a shift in focus toward sublethal effects assessment on physiology and behavior of beneficial insects. In this study, we assessed the risks posed by some insecticides with different mode of action through lethal and delayed systemic sublethal effects on the pupation, adult emergence, and repro- duction of the chrysopid Chrysoperla externa （Hagen, 1861; Neuroptera： Chrysopidae）, an important predator in pest biological control. The maximum field recommended dose （MFRD） and twice （2xMFRD） for chlorantraniliprole, tebufenozide, and pyriproxyfen were harmless to C. externa. In contrast, all the tested chitin synthesis inhibitors （CSIs） were highly detrimental to the predator, despite of their lack of acute lethal toxicity. There- fore, the safety assumed by using IGRs toward beneficial insects is not valid for chrysopids. Dose-response data showed that although all CSIs have a similar mechanism of action, the relative extent of toxicity may differ （novaluron 〉 lufenuron 〉 teflubenzuron）. For CSIs, the delayed systemic effects became obvious at adult emergence, where the predicted no observable effect dose （NOED） was 1/2 048 of the MFRD for novaluron （0.085 ng/insect）, and 1/256 of the MFRD for both lufenuron （0.25 ng/insect） and teflubenzuron （0.6 ng/insect）. Finally, this work emphasized the significance of performing toxicity risk assessments with an adequate posttreatment period to avoid underestimating the toxicities of insecticides, as the acute lethal toxicity assays may not provide accurate information regarding the long-range effects of hazardous compounds.
文摘Understanding predator-prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea （Stephens）, preying upon eggs and first instar larvae of the cotton bollworm, Helicoverpa armigera Hubner. The first and second instar larvae of C. carnea exhibited typeⅡ functional responses against both prey stages. However, the third instar larvae of C. carnea showed a type II functional response to the first instar larvae of H. armigera, but a typeⅢ functional response to the eggs. For the first instar larvae of C. carnea, the attack rate on H. armigera eggs was significantly higher than that on the larvae, whereas the attack rate of the second instar C. carnea on H. armigera larvae was significantly higher than that on the eggs. For the third instar larvae of C. carnea, the attack rate on the larvae was 1.015±0.278/h, and the attack coefficient on the eggs was 0.036 ±0.005. The handling times of the third instar larvae on larvae and eggs were 0.087 ± 0.009 and 0.071 ± 0.001 h, respectively. The highest predation rate was found for the third instar larvae of C. carnea on H. armigera eggs. Results of this study revealed that the larvae of C. carnea, especially the third instar, had a good predation potential in controlling H. armigera eggs and larvae. However, for a comprehensive estimation of the bio- control abilities of C. carnea toward H, armigera, further field-based studies are needed.
