Chlorantraniliprole was introduced into China from 2008 as a novel insecticide to control the rice stem borer, Chilo suppressalis （Walker）. Cotesia chilonis （Matsumura） is the major parasitoid of C. suppressalis. ...Chlorantraniliprole was introduced into China from 2008 as a novel insecticide to control the rice stem borer, Chilo suppressalis （Walker）. Cotesia chilonis （Matsumura） is the major parasitoid of C. suppressalis. We collected seven populations of C. suppressalis and two populations of C. chilonis in different locations in China in 2009 to investigate the lethal effects of chlorantraniliprole on them. The populations of C. suppressalis from different regions showed various LD50 values ranging from 2.00 to 18.70 ng per larva. Chlorantraniliprole has negligible acute contact toxicity （LC50500 mg L-1） to C. chilonis and its oral toxicity is also much lower than that of fipronil （2 800-fold difference in LC50）. The results indicated that chlorantraniliprole is a good alterative in rice integrated pest management （IPM） programs. The susceptibility data of C. suppressalis will be useful for monitoring resistance levels in future.展开更多
Five genes encoding heat shock proteins（HSPs）, Cchsp40, Cchsp60, Cchsp70, Cchsc70 and Cchsp90, were cloned and sequenced from Cotesia chilonis using RT-PCR and RACE. The c DNA sequences of Cchsp40, Cchsp60, Cchsp70,...Five genes encoding heat shock proteins（HSPs）, Cchsp40, Cchsp60, Cchsp70, Cchsc70 and Cchsp90, were cloned and sequenced from Cotesia chilonis using RT-PCR and RACE. The c DNA sequences of Cchsp40, Cchsp60, Cchsp70, Cchsc70 and Cchsp90 were 1 265, 2 551, 2 094, 2 297 and 2 635 bp in length, respectively, with a molecular weight（MW） of 39.1, 60.6, 71.45, 70.19 and 82.92 k Da, respectively. The predicted amino acid sequences of these proteins showed high similarities with published HSPs of other insects in Hymenoptera. Analysis of genomic DNAs indicated that Cchsp40, Cchsp60, Cchsp70 and Cchsp90 lacked introns, but Cchsc70 contained an intron. The results also suggested that CcH SP40 in C. chilonis was the Type II HSP40, Cc HSP60 was a member of the mitochondrial HSP60 family, and Cc HSP90 was a part of cytoplasmic HSP90 A family. Expression patterns varied in the five Cchsps in response to temperature. Expression of Cchsp40 and Cchsp60 was induced significantly by cold but not heat stress. Cchsp70 and Cchsc70 showed similar response to the thermal stress and could be induced by both cold and heat, but their expression levels were consistently lower than that of Cchsp40 and Cchsp60. Cchsp90 could be induced by heat stress and mild cold, but not cold stress. In addition, the results demonstrated Cchsc70 might be constitutive and inducible protein that was expressed during normal cell functioning and also up-regulated in response to stressful stimuli while Cchsp70 was solely inducible protein induced by temperature changes. Overall, results generated from this study could significantly advance the understanding of Cchsps in response to temperature and provide important biological information for C. chilonis insects that reared under different temperatures.展开更多
In Diatraea saccharalis larvae, the Malpighian tubules are found along the digestive tube, extending from the middle mesenteric region to the end of the posterior intestine, where they come in contact with the rectum ...In Diatraea saccharalis larvae, the Malpighian tubules are found along the digestive tube, extending from the middle mesenteric region to the end of the posterior intestine, where they come in contact with the rectum to form the cryptonephridium. Scanning and transmission electron microscopy of non-parasitized and parasitized larvae by Cotesia flavipes have indicated that the tubules consist of secretory and reabsorption cells. In parasitized larvae, the occurrence of hemocytes and teratocytes around the tubules is indicative of their role in immunological defense;however, they were not observed in non-parasitized larvae. At day 9 of parasitism, the mitochondria-containing vacuoles and myelin-like figures show signs of degeneration. The results of this study have confirmed that C. flavipes manipulates the physiology and biochemistry of D. saccharalis because the Malpighian tubules of the parasitized larvae remain active until the parasitoid completes its pupal stage and is released from the host organism.展开更多
The parasitism rate and the caterpillar infestation were studied by intercropping Dendranthema flowering plants with some cruciferous crops. These flowering plants increased significantly the rate of Cotesia plutellae...The parasitism rate and the caterpillar infestation were studied by intercropping Dendranthema flowering plants with some cruciferous crops. These flowering plants increased significantly the rate of Cotesia plutellae parasitism in the adj acent plots. It reached to 42.96% in treatment plot and 18.19% in the control. Although there was no significant difference in no. of diamondback moth （DBM） larvae per plant, 29.09% in population reduction was occurred in treatment plot. Abundance of cabbage looper and armyworm were also lower in adjacent plot. But, small white butterfly population （23.46%） was higher in adjacent plots as the result of Dendranthema plant. From the present experiment, Dendranthema flowering plants should be cultivated in Brasssicaceous crops for the control of DBM by providing the essential resources to larval parasitoid C. plutellae adults and then, this plant can be used as attractive plant in the control of small white butterfly. Serious elimination （Rating 4） of candidate insecticides to adult C. plutellae was observed at their recommendation doses. Among them, less toxic effect to C. plutellae was occurred in O,O-dimethyl S-methylcarbamoylmethyl which is the highest LC50 （4,765 ppm） to DBM by leaf-disc bioassay method and the lowest LC50 （2,903 pprn） was found in marlathion. It was occurred that the test strain have resistance to the recommended dose of marlathion （1,243 ppm） and O,O-dimethyl S-methylcarbamoylmethyl （3,750 ppm）.展开更多
MicroRNAs(miRNAs)have started to play an important role in pest control,and novel miRNA-based transgenic insect-resistant plants are now emerging.However,an environmental risk assessment of these novel transgenic plan...MicroRNAs(miRNAs)have started to play an important role in pest control,and novel miRNA-based transgenic insect-resistant plants are now emerging.However,an environmental risk assessment of these novel transgenic plants expressing insect miRNAs must be undertaken before promoting their application.Here,transgenic miR-14 rice,which has high resistance to the rice stem borer Chilo suppressalis,was used as an example for evaluation in this study.Taking the tier 1 risk assessment method in Bacillus thuringiensis(Bt)crops as a reference,the effects of the direct exposure of a non-target parasitoid,Cotesia chilonis,to a high concentration of miRNA were evaluated.The results showed that direct feeding with miR-14 at high concentration had no significant effects on the biological parameters of Co.chilonis,whereas when miR-14 was injected into Ch.suppressalis-parasitized larvae,the development duration of Co.chilonis was significantly affected.In combination with the real conditions of the rice paddy field,it could be inferred that transgenic miR-14 rice has no significant negative effects on the important non-target parasitoid,Co.chilonis.These results will provide a foundation for the establishment of a new safety evaluation system for novel RNAi-based transgenic plants.展开更多
The nutritional physiology of the diamondback moth, Plutella xylostella, larvae was examined after parasitization by the solitary endoparasitoids Cotesia vestalis or Diadegma semiclausum. Examinations were performed i...The nutritional physiology of the diamondback moth, Plutella xylostella, larvae was examined after parasitization by the solitary endoparasitoids Cotesia vestalis or Diadegma semiclausum. Examinations were performed in two phases, one was examined at the time point of 24 h post-parasitization, and the other was done at the end of the 4th instar larvae of host. Rates of growth, food consumption, assimilation, excretion, and respiration were calculated as well as approximate digestibility and the rate ratios ECI （percent efficiency of conversion of ingested food to body substance）, and ECD （percent efficiency of conversion of digested food to body substance）. Parasitization by C. vestalis resulted in significant decrease in the rates of growth, feeding, excretion, assimilation, and respiration, but the final dry rate of respiration at the end of last larval stadium was elevated. The ECI and ECD were also reduced as the result of parasitization, but digestibility was increased. All these parameters in the larvae parasitized by D. semiclausum at 24 h post-parasitization were also significantly changed compared to the control; however, these differences were quantitatively, but not qualitatively before pupation, similar to those resulted from parasitization by C. vestalis. In spite of the similarities of the parasitism-induced effects caused by these endoparasitoids, the final metabolic rate, that is, the rate of intake of nutrients required to compensate for metabolism, was much lower in the larvae parasitized by C. vestalis than that of the larvae parasitized by D. semiclausum. All of the results discussed here will contribute toward explaining the different ways these two wasps regulate the parasitoid-host relationship.展开更多
Plant volatiles have been demonstrated to play an important role in regulat- ing the behavior of Cotesia plutellae, a major larval parasitoid of the diamondback moth （DBM）, Plutella xylostella, but little is current...Plant volatiles have been demonstrated to play an important role in regulat- ing the behavior of Cotesia plutellae, a major larval parasitoid of the diamondback moth （DBM）, Plutella xylostella, but little is currently known about the function of each volatile and their mixtures. We selected 13 volatiles of the DBM host plant, a cruciferous veg- etable, to study the electroantennogram （EAG） and behavioral responses of C. plutellae. EAG responses to each of the compounds generally increased with concentration. Strong EAG responses were to 100 μL/mL of trans-2-hexenal, benzaldehyde, nonanal and cis-3- hexenol, and 10/zL/mL of trans-2-hexenal and benzaldehyde with the strongest response provoked by trans-2-hexenal at 100μL/mL. In the Y-tube olfactometer, C. plutellae, was significantly attracted by 1μL/mL of trans-2-hexenal and benzaldehyde.β-caryophyllene, cis-3-hexenol or trans-2-hexenal significantly attracted C. plutellae at 10μL/mL, while nonanal, benzyl alcohol, cis-3-hexenol or benzyl cyanide at 100μL/mL significantly at- tracted C. plutellae. Trans-2-hexenal significantly repelled C. plutellae at 100 μL/mL. EAG of C. plutellae showed strong responses to all mixtures made of five various com- pounds with mixtures 3 （trans-2-hexenal, benzaldehyde, nonanal, cis-3-hexenol, benzyl cyanide, farnesene, eucalyptol） and 4 （trans-2-hexenal, benzaldehyde, benzyl alcohol, （R）- （＋）-limonene,β-ionone, farnesene, eucalyptol） significantly attracting C. plutellae. These findings demonstrate that the behavior of C. plutellae can be affected either by individual compounds or mixtures of plant volatiles, suggesting a potential of using plant volatiles to improve the efficiency of this parasitoid for biocontrol ofP. xylostella.展开更多
Odorant-binding proteins(OBPs)are crucial in insect's olfactory perception,which participate in the initial step of odorant molecules transporting from the external environment to olfactory receptor neurons.To bet...Odorant-binding proteins(OBPs)are crucial in insect's olfactory perception,which participate in the initial step of odorant molecules transporting from the external environment to olfactory receptor neurons.To better understand the roles for OBPs in olfactory perception in Cotesia vestalis,a solitary larval endoparasitoid of diamondback moth,Plutella xylostella,we have comprehensively screened the genome of C.vestalis,and obtained 20 CvesOBPs,including 18 classic OBPs and two minus-C OBPs.Motif-pattern analysis indicates that the motifs of C.vestalis OBPs are highly conserved in Hymenoptera.The results of tissue expression analysis show that five OBPs(CvesOBP1/11/12/14/16)are highly expressed in male antennae,whereas six other OBP genes(CvesOBP7/8/13/17/18/19)are significantly transcriptionally enriched in female antennae.The results of RNA interference experiments for three most highly expressed OBP genes(CvesOBP17/18/19)in female antennae demonstrate that they are likely involved in parasitic processes of female wasps,as the wasps take a longer time to target the hosts when they are knoc ked down.展开更多
Polydnaviruses （PDVs） are a group of insect DNA viruses, which exhibit a mutual symbiotic relationship with their specific host wasps. Moreover, most encapsidated genes identified so far in PDVs share homologies wit...Polydnaviruses （PDVs） are a group of insect DNA viruses, which exhibit a mutual symbiotic relationship with their specific host wasps. Moreover, most encapsidated genes identified so far in PDVs share homologies with insect-originated genes, but not with virus-originated genes. In the meantime, PDVs associated with 2 wasp genera Cotesia and Glytapanteles encode some genes presumably originated from other viruses. Cotesia plutellae bracovirus （CpBV） encodes 4 genes homologous to baculoviral p94： CpBV- E94k1, CpB V-E94k2, CpB V-E94k3, and CpB V-E94k4. This study was conducted to predict the origin of CpB V-E94ks by comparing their sequences with those ofbaculoviral orthologs and to determine the physiological functions by their transient expressions in nonparasitized larvae and subsequent specific RNA interference. Our phylogenetic analysis indicated that CpBV-E94ks were clustered with other E94ks originated from different PDVs and shared high similarity with betabaculoviral p94s. These 4 CpBV genes were expressed during most developmental stages of the larvae of Plutella xylostella parasitized by C. plutellae. Expression of these 4 E94ks was mainly detected in hemocytes and fat body. Subsequent functional analysis by in vivo transient expression showed that all 4 viral genes significantly inhibited both host immune and developmental processes. These results suggest that CpB 11- E94ks share an origin with betabaculoviral p94s and play parasitic roles in suppressing host immune and developmental processes.展开更多
The seasonal changes of insecticide resistance and stability in hymenopteran Cotesia plutellae, collected from Jianxin, Fuzhou-City, and Shangjie, Minhou-County, Fujian, China, were assessed by using a dry residual fi...The seasonal changes of insecticide resistance and stability in hymenopteran Cotesia plutellae, collected from Jianxin, Fuzhou-City, and Shangjie, Minhou-County, Fujian, China, were assessed by using a dry residual film method. The resistance to two insecticides in the field populations of C. plutellae was not stable under insecticide-free conditions in the insectarium. Compared with susceptible F11 progeny of C. plutellae in the insectarium, the resistance ratios （RR） in F0 parents were 18.4 for fenvalerate and 11.4 for cypermethrin based on LC50 at 9 hours, and 32.8 for fenvalerate and 28.5 for cypermethrin based on LC50 at 24 hours when the parasitoids were left in contact with the insecticides for 1 hour and mortalities were recorded at 9 and 24 hours, respectively. However, the RR in a field population of C. plutellae were 9.2 for fenvalerate and 12.7 for cypermethrin, if the parasitoids were left in contact with the insecticides for 24 hours. The resistances to the two pyrethroids in other field populations collected from Jianxin and Shangjie from November 2000 and July 2004 were also determined. Significant seasonal variations of resistance to the two insecticides in the field populations of C. plutellae were found. The RR were 3.0-18.4 for fenvalerate and 4.8-20.6 for cypermethrin in Jianxin populations from November 2000 to April 2002 based on LC50 at 9 h, and 2.3-13.6 for fenvalerate and 3.6-16.0 for cypermethrin in Shangjie populations from May 2002 to July 2004 based on LC50 at 24 hours. The resistance levels were high in spring and autumn and decreased sharply in summer. In addition, significant recovery from the knocked-down caused by the insecticides was found in the F0 and field populations of C. plutellae which were resistant to fenvalerate and cypermethrin if the parasitoids were left in contact with the pyrethroids for 1 hour. However, no recovery was found in susceptible F11 progeny.展开更多
Polydnavirus was purified from the calyx fluid of Cotesia plutellae ovary. The genomic features of C. plutellae polydnavirus (CpPDV) were investigated. The viral genome consists of at least 12 different segments and t...Polydnavirus was purified from the calyx fluid of Cotesia plutellae ovary. The genomic features of C. plutellae polydnavirus (CpPDV) were investigated. The viral genome consists of at least 12 different segments and the aggregate genome size is a lower estimate of 80kbp. By partial digestion of CpPDV DNA with BamHI and subsequent ligation with BamHI-cut plasmid Bluescript, a representative library of CpPDV genome was obtained.展开更多
基金supports from the National Basic Research Program of China (973 Program, 2007CB109202)the Special Agricultural Research Projects for Public Welfare, China (200803004)
文摘Chlorantraniliprole was introduced into China from 2008 as a novel insecticide to control the rice stem borer, Chilo suppressalis （Walker）. Cotesia chilonis （Matsumura） is the major parasitoid of C. suppressalis. We collected seven populations of C. suppressalis and two populations of C. chilonis in different locations in China in 2009 to investigate the lethal effects of chlorantraniliprole on them. The populations of C. suppressalis from different regions showed various LD50 values ranging from 2.00 to 18.70 ng per larva. Chlorantraniliprole has negligible acute contact toxicity （LC50500 mg L-1） to C. chilonis and its oral toxicity is also much lower than that of fipronil （2 800-fold difference in LC50）. The results indicated that chlorantraniliprole is a good alterative in rice integrated pest management （IPM） programs. The susceptibility data of C. suppressalis will be useful for monitoring resistance levels in future.
基金funded by the National Key R&D Program of China (2017YFD0200400)the National Basic Research Program of China (973 Program, 2013CB127604)
文摘Five genes encoding heat shock proteins（HSPs）, Cchsp40, Cchsp60, Cchsp70, Cchsc70 and Cchsp90, were cloned and sequenced from Cotesia chilonis using RT-PCR and RACE. The c DNA sequences of Cchsp40, Cchsp60, Cchsp70, Cchsc70 and Cchsp90 were 1 265, 2 551, 2 094, 2 297 and 2 635 bp in length, respectively, with a molecular weight（MW） of 39.1, 60.6, 71.45, 70.19 and 82.92 k Da, respectively. The predicted amino acid sequences of these proteins showed high similarities with published HSPs of other insects in Hymenoptera. Analysis of genomic DNAs indicated that Cchsp40, Cchsp60, Cchsp70 and Cchsp90 lacked introns, but Cchsc70 contained an intron. The results also suggested that CcH SP40 in C. chilonis was the Type II HSP40, Cc HSP60 was a member of the mitochondrial HSP60 family, and Cc HSP90 was a part of cytoplasmic HSP90 A family. Expression patterns varied in the five Cchsps in response to temperature. Expression of Cchsp40 and Cchsp60 was induced significantly by cold but not heat stress. Cchsp70 and Cchsc70 showed similar response to the thermal stress and could be induced by both cold and heat, but their expression levels were consistently lower than that of Cchsp40 and Cchsp60. Cchsp90 could be induced by heat stress and mild cold, but not cold stress. In addition, the results demonstrated Cchsc70 might be constitutive and inducible protein that was expressed during normal cell functioning and also up-regulated in response to stressful stimuli while Cchsp70 was solely inducible protein induced by temperature changes. Overall, results generated from this study could significantly advance the understanding of Cchsps in response to temperature and provide important biological information for C. chilonis insects that reared under different temperatures.
文摘In Diatraea saccharalis larvae, the Malpighian tubules are found along the digestive tube, extending from the middle mesenteric region to the end of the posterior intestine, where they come in contact with the rectum to form the cryptonephridium. Scanning and transmission electron microscopy of non-parasitized and parasitized larvae by Cotesia flavipes have indicated that the tubules consist of secretory and reabsorption cells. In parasitized larvae, the occurrence of hemocytes and teratocytes around the tubules is indicative of their role in immunological defense;however, they were not observed in non-parasitized larvae. At day 9 of parasitism, the mitochondria-containing vacuoles and myelin-like figures show signs of degeneration. The results of this study have confirmed that C. flavipes manipulates the physiology and biochemistry of D. saccharalis because the Malpighian tubules of the parasitized larvae remain active until the parasitoid completes its pupal stage and is released from the host organism.
文摘The parasitism rate and the caterpillar infestation were studied by intercropping Dendranthema flowering plants with some cruciferous crops. These flowering plants increased significantly the rate of Cotesia plutellae parasitism in the adj acent plots. It reached to 42.96% in treatment plot and 18.19% in the control. Although there was no significant difference in no. of diamondback moth （DBM） larvae per plant, 29.09% in population reduction was occurred in treatment plot. Abundance of cabbage looper and armyworm were also lower in adjacent plot. But, small white butterfly population （23.46%） was higher in adjacent plots as the result of Dendranthema plant. From the present experiment, Dendranthema flowering plants should be cultivated in Brasssicaceous crops for the control of DBM by providing the essential resources to larval parasitoid C. plutellae adults and then, this plant can be used as attractive plant in the control of small white butterfly. Serious elimination （Rating 4） of candidate insecticides to adult C. plutellae was observed at their recommendation doses. Among them, less toxic effect to C. plutellae was occurred in O,O-dimethyl S-methylcarbamoylmethyl which is the highest LC50 （4,765 ppm） to DBM by leaf-disc bioassay method and the lowest LC50 （2,903 pprn） was found in marlathion. It was occurred that the test strain have resistance to the recommended dose of marlathion （1,243 ppm） and O,O-dimethyl S-methylcarbamoylmethyl （3,750 ppm）.
基金funded by Science and Technology Innovation 2030-"Agricultural Biological Breeding"Major Project(2023ZD04062)the Experimental Technology Research Program of Zhejiang University(SYB202126).
文摘MicroRNAs(miRNAs)have started to play an important role in pest control,and novel miRNA-based transgenic insect-resistant plants are now emerging.However,an environmental risk assessment of these novel transgenic plants expressing insect miRNAs must be undertaken before promoting their application.Here,transgenic miR-14 rice,which has high resistance to the rice stem borer Chilo suppressalis,was used as an example for evaluation in this study.Taking the tier 1 risk assessment method in Bacillus thuringiensis(Bt)crops as a reference,the effects of the direct exposure of a non-target parasitoid,Cotesia chilonis,to a high concentration of miRNA were evaluated.The results showed that direct feeding with miR-14 at high concentration had no significant effects on the biological parameters of Co.chilonis,whereas when miR-14 was injected into Ch.suppressalis-parasitized larvae,the development duration of Co.chilonis was significantly affected.In combination with the real conditions of the rice paddy field,it could be inferred that transgenic miR-14 rice has no significant negative effects on the important non-target parasitoid,Co.chilonis.These results will provide a foundation for the establishment of a new safety evaluation system for novel RNAi-based transgenic plants.
基金Funding for this study was provided jointly by 973 Program （2006CB 102005）, Key Program of Natural Science Foundation of Zhejiang Province （Z306031）, National Science Funds for Distinguished Young Scholars （Grant No. 30625006）, Program for New Century Excellent Talents in University （NCET-04-0521）, Innovation Research Team Program of the Ministry of Education of China （IRT0355）, and the China Postdoctoral Science Foundation （20060400322）.
文摘The nutritional physiology of the diamondback moth, Plutella xylostella, larvae was examined after parasitization by the solitary endoparasitoids Cotesia vestalis or Diadegma semiclausum. Examinations were performed in two phases, one was examined at the time point of 24 h post-parasitization, and the other was done at the end of the 4th instar larvae of host. Rates of growth, food consumption, assimilation, excretion, and respiration were calculated as well as approximate digestibility and the rate ratios ECI （percent efficiency of conversion of ingested food to body substance）, and ECD （percent efficiency of conversion of digested food to body substance）. Parasitization by C. vestalis resulted in significant decrease in the rates of growth, feeding, excretion, assimilation, and respiration, but the final dry rate of respiration at the end of last larval stadium was elevated. The ECI and ECD were also reduced as the result of parasitization, but digestibility was increased. All these parameters in the larvae parasitized by D. semiclausum at 24 h post-parasitization were also significantly changed compared to the control; however, these differences were quantitatively, but not qualitatively before pupation, similar to those resulted from parasitization by C. vestalis. In spite of the similarities of the parasitism-induced effects caused by these endoparasitoids, the final metabolic rate, that is, the rate of intake of nutrients required to compensate for metabolism, was much lower in the larvae parasitized by C. vestalis than that of the larvae parasitized by D. semiclausum. All of the results discussed here will contribute toward explaining the different ways these two wasps regulate the parasitoid-host relationship.
基金This work was funded by the project of National Nat- ural Science Foundation of China （No. 31230061）, and the National Key Basic Research Program of China （No. 2011CB100404） and the Science Fund for Distinguished Young Scholars in Fujian （No. 2011J06007）. GMG is supported by the National Thousand Talents Program in China and the Advanced Talents of SAEFA, and LV by the Minjiang Scholar Program in Fujian Province （China） and the Advanced Talents of SAFEA.
文摘Plant volatiles have been demonstrated to play an important role in regulat- ing the behavior of Cotesia plutellae, a major larval parasitoid of the diamondback moth （DBM）, Plutella xylostella, but little is currently known about the function of each volatile and their mixtures. We selected 13 volatiles of the DBM host plant, a cruciferous veg- etable, to study the electroantennogram （EAG） and behavioral responses of C. plutellae. EAG responses to each of the compounds generally increased with concentration. Strong EAG responses were to 100 μL/mL of trans-2-hexenal, benzaldehyde, nonanal and cis-3- hexenol, and 10/zL/mL of trans-2-hexenal and benzaldehyde with the strongest response provoked by trans-2-hexenal at 100μL/mL. In the Y-tube olfactometer, C. plutellae, was significantly attracted by 1μL/mL of trans-2-hexenal and benzaldehyde.β-caryophyllene, cis-3-hexenol or trans-2-hexenal significantly attracted C. plutellae at 10μL/mL, while nonanal, benzyl alcohol, cis-3-hexenol or benzyl cyanide at 100μL/mL significantly at- tracted C. plutellae. Trans-2-hexenal significantly repelled C. plutellae at 100 μL/mL. EAG of C. plutellae showed strong responses to all mixtures made of five various com- pounds with mixtures 3 （trans-2-hexenal, benzaldehyde, nonanal, cis-3-hexenol, benzyl cyanide, farnesene, eucalyptol） and 4 （trans-2-hexenal, benzaldehyde, benzyl alcohol, （R）- （＋）-limonene,β-ionone, farnesene, eucalyptol） significantly attracting C. plutellae. These findings demonstrate that the behavior of C. plutellae can be affected either by individual compounds or mixtures of plant volatiles, suggesting a potential of using plant volatiles to improve the efficiency of this parasitoid for biocontrol ofP. xylostella.
基金the National Science Foundation of China(31630060,31672079 and 31772522)the Zhejiang Provincial Natural Science Foundation of China(LR 18C140001).
文摘Odorant-binding proteins(OBPs)are crucial in insect's olfactory perception,which participate in the initial step of odorant molecules transporting from the external environment to olfactory receptor neurons.To better understand the roles for OBPs in olfactory perception in Cotesia vestalis,a solitary larval endoparasitoid of diamondback moth,Plutella xylostella,we have comprehensively screened the genome of C.vestalis,and obtained 20 CvesOBPs,including 18 classic OBPs and two minus-C OBPs.Motif-pattern analysis indicates that the motifs of C.vestalis OBPs are highly conserved in Hymenoptera.The results of tissue expression analysis show that five OBPs(CvesOBP1/11/12/14/16)are highly expressed in male antennae,whereas six other OBP genes(CvesOBP7/8/13/17/18/19)are significantly transcriptionally enriched in female antennae.The results of RNA interference experiments for three most highly expressed OBP genes(CvesOBP17/18/19)in female antennae demonstrate that they are likely involved in parasitic processes of female wasps,as the wasps take a longer time to target the hosts when they are knoc ked down.
文摘Polydnaviruses （PDVs） are a group of insect DNA viruses, which exhibit a mutual symbiotic relationship with their specific host wasps. Moreover, most encapsidated genes identified so far in PDVs share homologies with insect-originated genes, but not with virus-originated genes. In the meantime, PDVs associated with 2 wasp genera Cotesia and Glytapanteles encode some genes presumably originated from other viruses. Cotesia plutellae bracovirus （CpBV） encodes 4 genes homologous to baculoviral p94： CpBV- E94k1, CpB V-E94k2, CpB V-E94k3, and CpB V-E94k4. This study was conducted to predict the origin of CpB V-E94ks by comparing their sequences with those ofbaculoviral orthologs and to determine the physiological functions by their transient expressions in nonparasitized larvae and subsequent specific RNA interference. Our phylogenetic analysis indicated that CpBV-E94ks were clustered with other E94ks originated from different PDVs and shared high similarity with betabaculoviral p94s. These 4 CpBV genes were expressed during most developmental stages of the larvae of Plutella xylostella parasitized by C. plutellae. Expression of these 4 E94ks was mainly detected in hemocytes and fat body. Subsequent functional analysis by in vivo transient expression showed that all 4 viral genes significantly inhibited both host immune and developmental processes. These results suggest that CpB 11- E94ks share an origin with betabaculoviral p94s and play parasitic roles in suppressing host immune and developmental processes.
基金Acknowledgments This work was supported by the Natural Science Foundation of Fujian, China （No. B0410016） and China-Japan Cooperation Program by Science and Technique Bureau of Fujian Province, China （20051002）. This work was also supported in part by Grants-in-Aid from the Japan Society for the Promotion of Science （Nos. （A） 11356002 and （C） 14606001） and China-Japan Cooperated Program by JSPS.
文摘The seasonal changes of insecticide resistance and stability in hymenopteran Cotesia plutellae, collected from Jianxin, Fuzhou-City, and Shangjie, Minhou-County, Fujian, China, were assessed by using a dry residual film method. The resistance to two insecticides in the field populations of C. plutellae was not stable under insecticide-free conditions in the insectarium. Compared with susceptible F11 progeny of C. plutellae in the insectarium, the resistance ratios （RR） in F0 parents were 18.4 for fenvalerate and 11.4 for cypermethrin based on LC50 at 9 hours, and 32.8 for fenvalerate and 28.5 for cypermethrin based on LC50 at 24 hours when the parasitoids were left in contact with the insecticides for 1 hour and mortalities were recorded at 9 and 24 hours, respectively. However, the RR in a field population of C. plutellae were 9.2 for fenvalerate and 12.7 for cypermethrin, if the parasitoids were left in contact with the insecticides for 24 hours. The resistances to the two pyrethroids in other field populations collected from Jianxin and Shangjie from November 2000 and July 2004 were also determined. Significant seasonal variations of resistance to the two insecticides in the field populations of C. plutellae were found. The RR were 3.0-18.4 for fenvalerate and 4.8-20.6 for cypermethrin in Jianxin populations from November 2000 to April 2002 based on LC50 at 9 h, and 2.3-13.6 for fenvalerate and 3.6-16.0 for cypermethrin in Shangjie populations from May 2002 to July 2004 based on LC50 at 24 hours. The resistance levels were high in spring and autumn and decreased sharply in summer. In addition, significant recovery from the knocked-down caused by the insecticides was found in the F0 and field populations of C. plutellae which were resistant to fenvalerate and cypermethrin if the parasitoids were left in contact with the pyrethroids for 1 hour. However, no recovery was found in susceptible F11 progeny.
文摘Polydnavirus was purified from the calyx fluid of Cotesia plutellae ovary. The genomic features of C. plutellae polydnavirus (CpPDV) were investigated. The viral genome consists of at least 12 different segments and the aggregate genome size is a lower estimate of 80kbp. By partial digestion of CpPDV DNA with BamHI and subsequent ligation with BamHI-cut plasmid Bluescript, a representative library of CpPDV genome was obtained.
