筛胸梳爪叩甲幼虫对不同食物源的趋向行为及头部感器电镜扫描观察

Foraging behavior toward different food baits and observation of sensilla on the head surface of Melanotus cribricollis larva( Coleoptera: Elateridae)

筛胸梳爪叩甲(Melanotus cribricollis)是我国南方竹林区重要的地下害虫,监测及防治相当困难。为了探索竹林金针虫搜索地下食物的机制,利用四臂嗅觉仪测定了筛胸梳爪叩甲幼虫对不同食物的行为反应,并通过扫描电镜技术观察了筛胸梳爪叩甲幼虫触角、下颚须和下唇须感器的类型、数量、形态及分布特征。结果表明:发芽的玉米、小麦种子及竹笋均能吸引到金针虫,鲜竹笋的引诱能力显著强于发芽种子和燕麦。筛胸梳爪叩甲幼虫触角上分布有刺形感器、锥形感器、钩形感器、圆盘形感器4类8种,下颚须上分布有锥形感器、腔锥形感器和坛形感器3类4种,下唇须上则分布有锥形感器、腔锥形感器、坛形感器、毛形感器、乳突形感器、凹槽形感器、哑铃形感器7类9种。这些研究结果证实了植物挥发物在金针虫觅食过程中发挥着重要作用,同时为揭示幼虫头部感器在觅食过程中的功能和作用奠定了基础。

Melanotus cribricollis （Coleoptera： Elateridae） is a dominant soildwelling insect that is known to damage and destroy bamboo shoots in southern China. It is very difficult to monitor and control this kind of wireworm. To aim at understanding the mechanism of food foraging of wireworm below ground, we tested the orientation behavior towards different food baits and observed the type, amount and distribution of sensilla on the antennae, maxillary palp and labial palp of Melanotus cribricollis larva’s head surface by using scanning electron microscopy. The results showed that wireworms were attracted by germinating seeds of corn and wheat, and bamboo shoots, and the attraction of wireworms towards bamboo shoots was significantly stronger than that towards germinating seeds of corn and wheat, and raw oatmeal. Four types of sensilla were recorded in antennae including sensilla chaetica, sensilla basiconica, hook sensilla and dickshape sensilla. Three types of sensilla, including sensilla basiconica, sensilla coeloconica and sensilla ampullaceal, were found in maxillary palp; seven types of sensilla were observed on labial palp surface, including sensilla basiconica, sensilla coeloconica, sensilla ampullaceal, sensilla trichodea, sensilla processus mastoideus, sensilla groove and sensilla dumbbell. Our results confirmed that volatile organic compounds （VOCs） played an important role in food foraging of wireworm, and provided basic information for understanding the function of sensilla of larval head in food foraging.