河曲丝叶蜂在拉萨的发生规律及防治策略

Occurrence and control strategy of Nematus hequensis Xiao in Lhasa

为明确河曲丝叶蜂Nematus hequensis Xiao在拉萨的发生规律,本研究通过在柳树上进行室外定期、不定期的系统调查和室内饲养相结合,调查研究了河曲丝叶蜂的形态特征、生物学习性和发生规律。经调查研究,河曲丝叶蜂在9月下旬以老熟幼虫在土中结茧越冬,越冬基数170头/m^2;完全变态发育;幼虫共5龄;1～5龄幼虫的体长、体宽分别为(2.0～3.0 mm,<1.0 mm)、(7.2 mm,1.1 mm)、(12.0 mm,1.5 mm)、(16.8 mm,2.6 mm)、(24.0 mm,3.4 mm);河曲丝叶蜂在拉萨1年发生1代,每年7月中旬开始化蛹,7月底开始羽化,8月初开始孵化,孵化盛期为8月21日至9月2日,孵化末期为9月12日,为害高峰期为8月下旬至9月上旬。

To explore the occurrence of Nematus hequensis Xiao in Lhasa, we investigated the morphological characteristics, biological characteristics and occurrence by regular, irregular systematic outdoor survey on willow trees and indoor rearing. The results showed that N.hequensis overwinters by mature larva making cocoon in the soil in late September, with the overwintered cardinal number of 170 individuals per m 2. N.hequensis was of complete metamorphosis and could be divided into five instars. The body length and body width of the 1-5 instar larvae were 2.0-3.0 mm,and <1.0 mm, 7.2 mm and 1.1 mm, 12.0 mm and 1.5 mm , 16.8 mm and 2.6 mm, 24.0 mm and 3.4 mm, respectively. N.hequensis began to pupate in mid July. The emergence of N.hequensis started at the end of July. The hatching of egg began in the early August, the main period of hatching was from August 21st to September 2nd, and the late hatching period was September 12th. The damage peak period was from late August to early September.