韭菜迟眼蕈蚊雌成虫对其不同虫态气味的行为反应

【目的】明确韭菜迟眼蕈蚊Bradysiaodoriphaga Yang et Zhang雌成虫对不同虫态的行为趋性及起作用的活性物质,为开发高效引诱剂诱杀成虫的绿色防控技术提供基础。【方法】采用Y型嗅觉仪测定未交配或已交配韭菜迟眼蕈蚊雌成虫对2龄幼虫、4龄幼虫、蛹和卵块挥发物的趋性,应用固相微萃取和气-质联用仪对有引诱活性虫态挥发物进行定性和定量分析,然后进一步采用Y型嗅觉仪测定不同化学成分及比例对雌虫的引诱活性。【结果】结果表明,未交配或者已交配韭菜迟眼蕈蚊雌成虫明显嗜好4龄幼虫,而对2龄幼虫、蛹和卵块无明显趋性。韭菜迟眼蕈蚊4龄幼虫体表挥发物主要成分是二丙基二硫醚和2,2-二甲基-1,3-噻烷等二硫化物,前者含量是后者的10倍。50 mg二丙基二硫醚单体对韭菜迟眼蕈蚊交配雌成虫具有明显吸引作用,50 mg和5 mg 2,2-二甲基-1,3-噻烷单体对韭菜迟眼蕈蚊交配雌成虫具有一定吸引作用;二丙基二硫醚与2,2-二甲基-1,3-噻烷以1︰1(50 mg︰50 mg)和10︰1(50 mg︰5 mg)混合物对韭菜迟眼蕈蚊交配雌成虫具有明显吸引作用;而将二丙基二硫醚和2,2-二甲基-1,3-噻烷以10︰1(50 mg︰5 mg)混合后与50 mg二丙基二硫醚单体比较,前者对韭菜迟眼蕈蚊交配雌成虫的吸引作用更明显。【结论】韭菜迟眼蕈蚊雌成虫明显嗜好4龄幼虫,其体表挥发物二丙基二硫醚等二硫化物对韭菜迟眼蕈蚊雌成虫具有吸引作用,2,2-二甲基-1,3-噻烷对二丙基二硫醚单体吸引韭菜迟眼蕈蚊交配雌成虫具有增效作用。

Behavioral responses of female Bradysiaod oriphaga Yang et Zhang to volatiles of conspecific larvae,pupae and eggs

Objectives] To determine the preferences of adult female Bradysiaodoriphaga Yang et Zhang to volatile compounds emitted by conspecific larvae, pupae and eggs, in order to find more effective lures for trapping, and establishing green control technology for this pest. Methods] The behavioral responses of female B. odoriphaga Yang et Zhang to volatiles emitted by conspecific 2nd and 4th instar larvae, pupae and eggs were investigated using a Y-tube olfactometer. Volatile substances that attracted female adults were then qualitatively and quantitatively analyzed using solid micro-extraction (SPME) and a Gas Chromatography-Mass Spectrometer (GC-MS). The relative attractiveness of different chemical compounds, and ratios of compounds, to adult females were then determined using a Y-tube olfactometer. Results] Both virgin and mated adult females were significantly attracted to the volatiles emitted by 4th instar larvae, and were not attracted to those emitted by 2nd instar larvae, pupae or eggs. Dipropyl disulfide and 2, 2-dimethyl- 1, 3-dithiane were two main components of larval volatiles and the amount of the former was 10 fold that of the latter. Mated adult females were clearly attracted by 50mg of dipropyl disulfide, and also by 50mg or 5mg of 2, 2-dimethyl-1, 3-dithiane, but not significantly. Adult females were strongly attracted by 1︰1 (50 mg︰50 mg) and 10︰1(50 mg︰5mg) ratios of dipropyl disulfide:2, 2-dimethyl-1,3-dithiane. The 10︰1 (50 mg︰5 mg) ratio of dipropyl disulfide: 2, 2-dimethyl- 1, 3-dithiane was significantly more attractive than 50 mg of dipropyl disulfide. Conclusion] Female B. odoriphaga significantly prefer the odor of 4th instar larvae and are attracted by dipropyldisulfide et al.disulfides, the attractiveness of which can be increased by the addition of 2, 2-dimethyl-1, 3-dithiane.