亚麻荠对小菜蛾幼虫取食和成虫行为反应的影响

Effect of false flax (Camelina sativa) on larval feeding and adult behavioral response of the diamondback moth (Plutella xylostella)

亚麻荠是一种很少有害虫危害的油料作物。用室内生测和Y型嗅觉仪研究了亚麻荠对小菜蛾Plutellaxylostella幼虫取食和成虫行为反应的影响。以甘蓝作对照 ,用亚麻荠叶片喂养的小菜蛾初孵幼虫 3天后校正死亡率为 79 2 % ,显示了较强的致死作用 ;喂养小菜蛾 3龄幼虫至化蛹 ,其存活率、化蛹率、蛹重及成虫寿命都显著降低 ,表明亚麻荠对小菜蛾幼虫的生长发育有不利影响。在幼虫的取食选择实验中 ,有甘蓝叶供选择时 ,小菜蛾幼虫不取食亚麻荠 ;在无可选择的情况下 ,小菜蛾幼虫也取食亚麻荠叶片 ,但取食量很小 ,与取食甘蓝叶的量相比 ,差异极显著。行为反应测试表明 ,小菜蛾成虫对甘蓝和亚麻荠植株的挥发物都有明显的趋性反应 ,与对照 (净化空气 )相比 ,差异极显著 ,而在甘蓝和亚麻荠之间无选择性。

False flax, Camelina sativa (L.), an oil_bearing crop, has an outstanding resistance to phytophagous insects. Effect of false flax on larval feeding and adult behavioral response of the diamondback moth, Plutella xylostella (L.), one of the most damaging pests in cruciferous crops, were examined with bioassay and Y_olfactometer in the laboratory. With feeding on cabbage as the control, the 1st instar larvae, fed on leaves of false flax, got a corrected death rate of 79.2% after 3 days, which indicated that false flax had an obvious antibiosis effect on the 1st instar larvae. The 3rd instar larvae, fed on false flax, showed significantly lower survival rate, percentage pupation, pupa weight and shorter adult longevity compared with those fed on cabbage. The diamondback moth larvae preferred leaves of cabbage to false flax in feeding choice test. In no_choice test, the amount of false flax leaves consumed by the diamondback moth larvae was significantly lower than that of cabbage. However, the test of behavior showed that adults of the diamondback moth had the same orientation response to false flax and cabbage; compared to clean air, adults of the diamondback moth preferred to odors from the plants of false flax or cabbage. These results indicated that the diamondback moth adults had an obvious orientation response to the volatiles of false flax.