3种半翅目小型昆虫的疏水行为及其前跗节结构比较

以茶小绿叶蝉、茶蚜和白背飞虱3种农业上重要的半翅目害虫为研究对象,观察比较它们在水面上的疏水行为及其前跗节的形态结构.结果表明,白背飞虱成虫和若虫均可站立于水面并具有较强的滑行能力,表明其前跗节疏水性最强;茶小绿叶蝉成虫可站立于水面,若虫足易陷入水中,表明成虫的前跗节疏水性强于若虫;茶蚜成虫和若虫足均陷入水中,表明其前跗节无疏水作用,但茶蚜成虫和若虫在水面均有聚集抱团现象;这3种昆虫都无法站立于大豆油面.电镜观察发现,茶小绿叶蝉成虫的前跗节较若虫更加扁平,爪中垫为一对椭圆形吸盘状结构,且表面附着的刺体数量显著多于若虫;茶蚜成虫和若虫具有一对发达的爪及2根棍棒状中垫毛,缺少爪垫及爪中垫;白背飞虱成虫和若虫具有发达的杯状吸盘结构的爪中垫.

Comparison on the hydrophobic behaviors and pretarsus morphology of three small Hemiptera species

Three small Hemiptera species of agricultural pests, tea green leafhopper Empoasca onukii Matsuda, tea aphid Toxoptera aurantii Boyer, and white back planthopper Sogatella furcifera ( Horváth) , were chosen to study their hydrophobic behaviors on wa-ter surface and pretarsus morphology. The results showed that both adult and nymph S. furcifera were able to stand on water surface and skip freely, indicating a high hydrophobility of the pretarsus of S. furcifera. Adult E. onukii was able to stand on water surface while five legs of its nymph dipped into water, which meant a higher hydrophobic pretarsus of the adult than the nymph. All legs of T. aurantii dipped into water, regardless of adult or nymph, indicating no hydrophobility of their pretarsi, but they grouped and drif-ted on water surface. Nevertheless, all species drown on oil surface. The shape of pretarsi was flatter in adult E. onukii than the nymph under scanning electron microscope, with more brochosomes on the pretarsus surface of the adult. Pretarsi of adult and nymph T. aurantii had the same structure, including a pair of claws and two stick-like arolium setas. Pretarsi of adult and nymph S. furcifera both had a big shallow, cup-like arolium which might have vacuuming function.