Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2013
Publication Date: 5/20/2014
Citation: Sun, X., Liu, Z., Zhang, A., Dong, H., Zeng, F., Pan, X., Wang, Y., Wang, M. 2014. Electrophysiological responses of the rice leaffolder, cnaphalocrocis medinalis (lepidoptera: pyralidae), to rice plant volatiles. Journal of Insect Science. 14(70). Interpretive Summary: The rice leaffolder is a serious rice pest that is widely distributed in rice-growing countries in Asia, Oceania, Australia, and Africa. It results in massive yield losses of rice at the reproductive stage. Early-season insecticide applications disrupt biological control efforts of this and other pest species. Environmentally friendly and other green approaches to control this pest are needed. In this study, we evaluated the antenna response of the insect to many synthetic chemical compounds that were known to be released from the rice plants and found that the sex, age, and mating status of the leaffolder affected its response to different tested compounds. This research result will help scientists and growers understand what kinds plant odor have been used by this pest as cues to locate the food source, mate location, and oviposition site; therefore, develop more effective, safe, and environmental friendly pest management strategies to control this insect.
Technical Abstract: The electrophysiological activities of 38 synthetic volatiles that were known to be released from the rice plants (Poaceae: Oryza spp.) were studied using electroantennogram (EAG) recording technique on male and female antennae of the rice leaffolder, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), one of the most destructive pests of rice. Several compounds that elicited the strongest EAG responses for each physiological condition were selected for EAG dose-response tests at five concentrations. The compounds that were screened in this way were: methyl salicylate, heptanol, linalool, cyclohexanol and 2-heptanone for 1-day-old male moths; heptanol, hexanal, (Z)-2-hexen-1-ol and nonadecane for 1-day-old females; methyl salicylate, heptanol, (E)-2-hexen-1-ol and (Z)-2-hexen-1-ol for 3-day-old males; linalool, heptanol, (E)-2-hexen-1-ol, 2-heptanone and hexanal for 3-day-old females; 2-heptanone, cyclohexanol, linalool, heptanol and methyl salicylate for 5-day-old virgin females; and methyl benzoate, (Z)-2-hexen-1-ol, heptanol, linalool and hexanal for 5-day-old mated females. Female and male C. medinalis exhibited broad over-lap in their EAG responses to individual plant odours, and there was no clear pattern of difference between responses of female and male antennae to different compounds. Statistical analyses revealed that both the chemical structures of volatile compounds and the physiological condition (age, sex and mating condition) have an effect on the EAG responses of C. medinalis.