曲纹紫灰蝶的生物学特性和发生动态研究

近年来 ,曲纹紫灰蝶Chiladespandava在广东省苏铁上大量发生 ,一些苏铁园 ,苏铁的受害株率为 2 0 %～ 3 0 % ,有的高达 5 0 %～ 60 %。调查研究了曲纹紫灰蝶的生物学特性及种群发生动态 ,结果如下。 ( 1 )幼虫分 4龄。据广州 9～ 1 0月的观察 ,卵的平均历期为 ( 1 5 2± 0 1 1 )d ,幼虫期为 ( 5 96± 0 1 9)d,蛹期为 ( 5 1 4± 0 3 8)d。成虫卵散产于苏铁嫩芽上。幼虫危害苏铁嫩芯 ,严重时苏铁的叶片、叶柄全部被吃光。 ( 2 )成虫在上午 9:3 0～ 1 0 :3 0活动数量最多。 ( 3 )曲纹紫灰蝶全年都能发生。成虫、卵、幼虫、蛹分别在 5月和 1 0月出现发生高峰 ,前峰高于后峰。其发生高峰期与苏铁的抽芯盛期相吻合。 ( 4 )防治策略 :合理采取措施压基数 ,综合防治控为害 ,即全年曲纹紫灰蝶防治的关键是掌握每年苏铁的第 1个抽芯高峰期 ,采取合理措施 ,压低曲纹紫灰蝶数量 ,持续监控发生动态 ,在第 2个发生高峰的卵孵化盛期用药防治。

The biology and population dynamics of the butterfly Chilades pandava

The butterfly Chilades pandava has recently caused serious damage to cycads in some localities in Guangdong Province with the rate of infestation reaching 20%～30% in some cycad gardens. This paper reports some preliminary data on the biology and population dynamics of this butterfly and puts forward a control strategy for this pest. The main results were as follows.(1) Four instars of the larvae caused serious damage to cycad shoots. Its egg, larva, pupal periods were 1.52±0.11, 5.96±0.19 and 5.14±0.38 days respectively. The eggs were dispersed on the shoots.(2) Adults were most active from 9:30 to 10:30 in the morning. (3) Eggs, larvae, pupae and adults coexist year round. There are two peaks of occurance in May and October for adults, eggs, larvae and pupae.(4) All kinds of effective measures, such as agricultural control and chemical control, should be applied to suppress the population of this pest.