In order to develop biological control of aphids by a ＂push-pull＂ approach, intercropping using repellent emitting plants was developed in different crop and associated plant models. Garlic is one of the potential p...In order to develop biological control of aphids by a ＂push-pull＂ approach, intercropping using repellent emitting plants was developed in different crop and associated plant models. Garlic is one of the potential plant that could be inserted in crops to decrease the pest occurrence in neighboring crop plots. In this study, field works were conducted in wheat fields in Langfang Experimental Station, Hebei Province in China from October 2009 to July 2010 during wheat developmental season. The effect of wheat intercropping with garlic but also the volatiles emission on the incidence of the English grain aphid, Sitobion avenae Fabricius （Homoptera： Aphididae） was assessed. Natural beneficial occurrence and global yields in two winter wheat varieties that were susceptible or resistant to cereal aphid were also determined comparing to control plots without the use of garlic plant intercrop nor semiochemical releaser in the fields. S. avenae was found to be lower in garlic oil blend treatment （GOB）, diallyl disulfide treatment （DD） and wheat-garlic intercropping treatment （WGI） when compared to the control plots for both two varieties （P〈0.01）. Both intercropping and application of volatile chemicals emitted by garlic could improve the population densities of natural enemies of cereal aphid, including ladybeetles and mummified aphids. Ladybeetle population density in WGI, GOB and mummified aphids densities in WGI, DD were significantly higher than those in control fields for both two varieties （P〈0.05）. There were significant interactions between cultivars and treatments to the population densities of S. avenae. The 1 000-grain weight and yield of wheat were also increased compared to the control. Due to their potential alternatives as a biological control agent against cereal aphid, garlic intercropping and related emitted volatiles are expected to contribute to the further improvement of integrated pest management systems and to potentially reduce the amount of traditional synthetic 展开更多
Huanglongbing （HLB） is the most destructive disease of citrus worldwide. The Asian citrus psyllid, Diaphorina citri Kuwayama （Hemiptera： Psyllidae）, is the vector of the phloem-inhabiting bacterium, Candidatus Li...Huanglongbing （HLB） is the most destructive disease of citrus worldwide. The Asian citrus psyllid, Diaphorina citri Kuwayama （Hemiptera： Psyllidae）, is the vector of the phloem-inhabiting bacterium, Candidatus Liberibacter asiaticus, which is presumed to cause HLB in Florida citrus. Laboratory and field studies were conducted to examine the behavioral responses of male and female D. cirri to their cuticular extracts. In olfactometer assays, more male D. citri were attracted to one, five, or 10 female cuticular extract equivalent units than blank controls. The results were confirmed in field studies in which clear or yellow traps baited with 10 female cuticular extract equivalent units attracted proportionately more males than clear traps baited with male cuticular extract or unbaited traps. Analyses of cuticular constituents of male and female D. citri revealed differences between the sexes in chemical composition of their cuticular extracts. Laboratory bioassays with synthetic chemicals identified from cuticular extracts indicated that dodecanoic acid attracted more males than clean air. Traps baited with dodecanoic acid did not increase total catch olD. citri as compared with blank traps at the dosages tested; however, the sex ratio ofpsyllid catch was male biased on traps baited with the highest lure loading dosage tested （10.0 mg）.展开更多
When female blow flies Lucilia sericata and Phormia regina （Diptera： Cal- liphoridae） oviposit in aggregations on carrion, even-aged larval offspring reportedly de- velop faster, and fewer are parasitized or preyed...When female blow flies Lucilia sericata and Phormia regina （Diptera： Cal- liphoridae） oviposit in aggregations on carrion, even-aged larval offspring reportedly de- velop faster, and fewer are parasitized or preyed upon. The benefits of aggregated ovipo- sition equally affect con- and heterospecific larvae sharing a resource. The benefits imply that female blow flies engage in coordinated, pheromone-mediated oviposition behavior. Yet, repeated attempts to identify oviposition pheromones have failed invoking doubt that they exist. Simply by regurgitating and feeding on carrion, flies may produce attractive semiochemicals. If flies were to aggregate in response to feeding flies rather than oviposit- ing flies, then the semiochemical cue（s） may be associated with the salivary gland. Working with L. sericata and P.. regina and using liver as a surrogate oviposition medium, we test the hypotheses, and present data in their support, that （i） gravid or nongravid females ovipositing and/or feeding on liver enhance its attractiveness to gravid and nongravid fe- males; （ii） females respond to semiochemicals from feeding heterospecific females; （iii） females respond equally well to semiochemicals from feeding con- and heterospecific females; （iv） macerated head tissues of females applied to liver enhance its attractiveness; and （v） females in direct contact with and feeding on liver, but not when next to yet physically separated from liver, enhance attraction of flies. We conclude that oviposition site-seeking females do not respond to an oviposition pheromone. Instead, they appear to coopt semiochemicals associated with feeding flies as resource indicators, taking chances that resources are suitable for oviposition, and that ovipositing flies are present.展开更多
基金supported by grants from the Cooperation Project between Belgium and China (CUD\PIC Shandong, 2010DFA32810)
文摘In order to develop biological control of aphids by a ＂push-pull＂ approach, intercropping using repellent emitting plants was developed in different crop and associated plant models. Garlic is one of the potential plant that could be inserted in crops to decrease the pest occurrence in neighboring crop plots. In this study, field works were conducted in wheat fields in Langfang Experimental Station, Hebei Province in China from October 2009 to July 2010 during wheat developmental season. The effect of wheat intercropping with garlic but also the volatiles emission on the incidence of the English grain aphid, Sitobion avenae Fabricius （Homoptera： Aphididae） was assessed. Natural beneficial occurrence and global yields in two winter wheat varieties that were susceptible or resistant to cereal aphid were also determined comparing to control plots without the use of garlic plant intercrop nor semiochemical releaser in the fields. S. avenae was found to be lower in garlic oil blend treatment （GOB）, diallyl disulfide treatment （DD） and wheat-garlic intercropping treatment （WGI） when compared to the control plots for both two varieties （P〈0.01）. Both intercropping and application of volatile chemicals emitted by garlic could improve the population densities of natural enemies of cereal aphid, including ladybeetles and mummified aphids. Ladybeetle population density in WGI, GOB and mummified aphids densities in WGI, DD were significantly higher than those in control fields for both two varieties （P〈0.05）. There were significant interactions between cultivars and treatments to the population densities of S. avenae. The 1 000-grain weight and yield of wheat were also increased compared to the control. Due to their potential alternatives as a biological control agent against cereal aphid, garlic intercropping and related emitted volatiles are expected to contribute to the further improvement of integrated pest management systems and to potentially reduce the amount of traditional synthetic
文摘Huanglongbing （HLB） is the most destructive disease of citrus worldwide. The Asian citrus psyllid, Diaphorina citri Kuwayama （Hemiptera： Psyllidae）, is the vector of the phloem-inhabiting bacterium, Candidatus Liberibacter asiaticus, which is presumed to cause HLB in Florida citrus. Laboratory and field studies were conducted to examine the behavioral responses of male and female D. cirri to their cuticular extracts. In olfactometer assays, more male D. citri were attracted to one, five, or 10 female cuticular extract equivalent units than blank controls. The results were confirmed in field studies in which clear or yellow traps baited with 10 female cuticular extract equivalent units attracted proportionately more males than clear traps baited with male cuticular extract or unbaited traps. Analyses of cuticular constituents of male and female D. citri revealed differences between the sexes in chemical composition of their cuticular extracts. Laboratory bioassays with synthetic chemicals identified from cuticular extracts indicated that dodecanoic acid attracted more males than clean air. Traps baited with dodecanoic acid did not increase total catch olD. citri as compared with blank traps at the dosages tested; however, the sex ratio ofpsyllid catch was male biased on traps baited with the highest lure loading dosage tested （10.0 mg）.
文摘When female blow flies Lucilia sericata and Phormia regina （Diptera： Cal- liphoridae） oviposit in aggregations on carrion, even-aged larval offspring reportedly de- velop faster, and fewer are parasitized or preyed upon. The benefits of aggregated ovipo- sition equally affect con- and heterospecific larvae sharing a resource. The benefits imply that female blow flies engage in coordinated, pheromone-mediated oviposition behavior. Yet, repeated attempts to identify oviposition pheromones have failed invoking doubt that they exist. Simply by regurgitating and feeding on carrion, flies may produce attractive semiochemicals. If flies were to aggregate in response to feeding flies rather than oviposit- ing flies, then the semiochemical cue（s） may be associated with the salivary gland. Working with L. sericata and P.. regina and using liver as a surrogate oviposition medium, we test the hypotheses, and present data in their support, that （i） gravid or nongravid females ovipositing and/or feeding on liver enhance its attractiveness to gravid and nongravid fe- males; （ii） females respond to semiochemicals from feeding heterospecific females; （iii） females respond equally well to semiochemicals from feeding con- and heterospecific females; （iv） macerated head tissues of females applied to liver enhance its attractiveness; and （v） females in direct contact with and feeding on liver, but not when next to yet physically separated from liver, enhance attraction of flies. We conclude that oviposition site-seeking females do not respond to an oviposition pheromone. Instead, they appear to coopt semiochemicals associated with feeding flies as resource indicators, taking chances that resources are suitable for oviposition, and that ovipositing flies are present.
