皖西南紫薇梨象生活史与危害特性研究

Study on life history and occurrence of Pseudorobitis gibbus Redtenbacher(Coleoptera:Apionidae)in Anqing

紫薇梨象(Pseudorobitis gibbusRedtenbacher)是一种危害紫薇的重要害虫,近年来在安徽等地发生严重。笔者对其生活史与危害特性进行了观测分析。结果表明,紫薇梨象在安徽省安庆地区1年1代,以成虫(43.9%)和老熟幼虫(56.1%)越冬。越冬成虫翌年4月中旬出果上树为害;越冬幼虫4月上旬化蛹、6月中旬羽化成虫上树取食为害。紫薇梨象对紫薇危害部位较广(嫩梢、花芽、花蕾、蒴果等),其中以嫩梢和蒴果受害最为严重。不同紫薇品系的被害率分析表明,紫薇梨象对翠薇和银薇的危害性要明显高于南紫薇。研究证实,紫薇蒴果是紫薇梨象越冬场所,清除蒴果是防除该虫的行之有效的主要措施。因此,在紫薇梨象越冬前(9月上、中旬)对紫薇果枝进行修剪能够显著降低紫薇梨象的危害。

Pseudorobitis gibbusRedtenbacher is an important insect pest of crape myrtle（Lagerstroemia indicaLinn.）,recently.P. gibbushas become a great threat on the plantation of crape myrtle in Anqing, Anhui Province. In this study,we investigated the life history and harmful characteristics ofP. gibbusin Anqing.P. gibbusis univoltine, one generationper year.P. gibbusoverwinters as adults（43.9%） and larvae（56.1%） within the capsular fruit of crape myrtle. In mid-dle of April, overwintering adults came out from capsular fruit and began to infest crape myrtle. The overwintering larvaealso started to pupate in early April, and then the adults emerged in middle June.P. gibbusinfested most of organs ofcrape myrtle, including tender shoots, buds, flowers and fruits. More serious damages appeared on the tender shoots andfruits of crape myrtle. Meanwhile, we observed thatP. gibbuspreferred to infestL. indicavar. albaandL. indicavar.rubra to L. subcostata. At last, we evaluated the effectiveness of pest control by pruning and removing the capsular fruitsbefore theP. gibbusoverwintering. The results showed that the the infection rate ofP.gilbusto crape myrtle was signifi-cantly reduced by pruning in early or middle of September. Therefore, pruning fruit spur is one of effective approach toprevent and control this pest.