用四臂嗅觉仪观测家蚕对非桑科植物的选择行为

昆虫嗅觉、味觉等感受系统与其对宿主植物的识别、找寻、取食直接相关,也是研究昆虫与植物相互作用的重要内容。设计并制作观测家蚕行为的四臂嗅觉仪,应用于分析家蚕幼虫被宿主植物桑树的叶片与非宿主植物青蒿和樟树的叶片引诱而产生的行为反应。观测结果表明,非宿主植物青蒿的叶片对家蚕幼虫的引诱作用比宿主植物桑树叶片的引诱作用强,而樟树叶对2、3龄起蚕的引诱作用与桑叶无明显差异。家蚕幼虫对青蒿叶和樟树叶有咬食行为,对桑叶有持续进食行为。该结果证实:家蚕利用灵敏的嗅觉系统可识别植物挥发性气味物质,定位食物源,从而产生趋向行为;家蚕的味觉系统可能直接决定取食的初始行为及在短时间内是否持续、大量取食某种植物的行为。

An Observation on Food Selection Behavior of Silkworm Larvae to Non-Moraceae Plants with Four-arm Olfactometer

The olfaction,gustation and other sensory systems of an insect are directly related to its detection,seeking and feeding against the host plant.They are also the important targets for studies on the interaction between insect and plant.In this study,we designed a four-arm olfactometer to observe behavior of silkworm larvae and to analyze behavioral responses of the larvae seduced by leaves of the host plant(mulberry,Morus alba) and two non-host plant species(Artemisia annua and Cinnamomum camphora).The results showed that leaves of the non-host plant A.annua had stronger seductive effect to silkworm larvae than those of the host plant,while another non-host phant and C.camphora shared similar seductive effect to the 2nd and 3rd instar newly exuviated larvae with mulberry.Silkworm larvae had biting behavior to A.annua and C.camphora leaves and continuous feeding behavior to mulberry leaves.This result verifies that the sophisticated olfactory system enables silkworm larvae to detect volatile odor substance of plants,to locate food source and thus to activate the movement.Meanwhile,gustatory system of the larvae is probably directly related to their early feeding behavior and to further decision on whether or not to continue the feeding behavior.