福州市曲纹紫灰蝶的生物学特性及其防治

Biological characteristics and control strategy of Chilades pandava(Horsfield)in Fuzhou City

[目的]曲纹紫灰蝶是严重危害我国南方观赏树种苏铁的重要食叶害虫。调查福州市曲纹紫灰蝶对苏铁的为害情况,为当地防治该虫提供参考。[方法]选取福州市13个苏铁配置数量较多的公园和绿地,对曲纹紫灰蝶的发生情况、危害程度进行调查,并结合室内饲养观察其生物学特性。[结果]曲纹紫灰蝶在福州为害较为严重,常以幼虫取食苏铁的嫩叶、新梢以及新叶,严重时导致整株植株死亡。该虫在福州1 a发生4代,以蛹越冬,每个世代最短仅需32 d,包括卵期5 d、幼虫期10 d(幼虫期共4龄)、蛹期7 d和成虫期10 d。[结论]每年春、夏季为苏铁新叶的萌发和生长期,是曲纹紫灰蝶幼虫的为害高峰期和防治的关键期;在越冬蛹未羽化前清理虫蛹,可有效降低虫口数量。

[Purpose] Chilades pandava(Horsfield) is a serious caterpillar pest that infests the leaves of ornamental tree species, Cycas revoluta in south China. The infestation and damaged characteristics of Cycas revoluta in Fuzhou area was investigated to provide a reference for integrated pest management measures. [Method] A field survey was conducted in 13 parks and green sites in Fuzhou City, where a large number of Cycas revoluta are planted, and combined with indoor rearing to observe the biological characteristics of Chilades pandava. [Result] The infestation of Chilades pandava was relatively serious in Fuzhou City. The larva often feeds on tender leaves, new shoots and new leaves of Cycas revoluta, which led to broken leaves and shoots, and caused the death of the whole trees in severe cases. The pest undergos four generations annually in Fuzhou City, and overwinters as pupa. Each generation is as short as 32 days, including 5-day egg stage, 10-day larva stage(4 instar larvae), 7-day pupa stage, and 10-day adult stage. [Conclusion] Spring and summer are the germination and growth period of new leaves, which are the peak period of larval damage and the key period. Collecting and killing pupae are effective measures to reduce their population size prior to adult eclosion.