Abstract:

Galeruca daurica Joannis is an important pest that has serious outbreaks recently in Inner Mongolian grasslands. In order to investigate the mechanism of outbreaks, the effects of 13 common forage plants on the larval development, survival and feeding amount were investigated in the lab. The results showed that the larva was a specialist herbivore, and mainly fed on the genus Allium including A. mongolium, A. ramosum and A. polyrhizum. The tested Allium plants had significant effects on the larval and nymphal development durations and no significant effect on the larval survival rates. When fed on A. mongolium, A. ramosum and A. polyrhizum, the larval development durations of three were 24.27, 27.87 and 33.13 d, and the nymphal development durations were 6.61, 7.40 and 8.43 d, and the larval feeding amounts were 393.76, 442.51 and 496.09 mg (fresh weight), respectively. The feeding amount of 3^rd instar was the largest, accounting for 63.45%~67.46% of the whole larval duration, about 3 times of 2^nd instar and 5 times of 1^st instar. Therefore, A. mongolium is the most suitable for G. daurica larvae, following by A. ramosum and A. polyrhizum. Insecticide should be applied before the 3^rd instar when chemical control is necessary.

Key words: Galeruca daurica, Host plant, Development duration, Survival rate, Feeding amount

摘要：

沙葱萤叶甲（Galerucadaurica Joannis）为近年来严重危害内蒙古草原的重要害虫，为揭示其成灾机制，在室内测定了13种内蒙古草原常见牧草对沙葱萤叶甲幼虫生长发育、存活和取食的影响。结果表明：沙葱萤叶甲幼虫食性窄，主要取食沙葱（Allium mongolium）、野韭（A.ramosum）及多根葱（A.polyrhizum）等百合科葱属植物，其他供试植物基本无取食现象。沙葱、野韭及多根葱对沙葱萤叶甲幼虫期、蛹期和取食量有显著影响，而对其存活率影响不显著。幼虫取食沙葱、野韭和多根葱时，幼虫期和蛹期分别为24.27，27.87，33.13d和6.61，7.40，8.43d，取食量分别为393.76，442.51和496.09mg（鲜重），3龄幼虫食量最大，占幼虫期总食量的63.45%~67.46%，约为2龄幼虫的3倍、1龄幼虫的5倍。因此，沙葱是沙葱萤叶甲幼虫的最适寄主植物，其次为野韭，然后是多根葱；化学防治时，应在幼虫3龄以前进行。

关键词: 沙葱萤叶甲, 寄主植物, 发育历期, 存活率, 取食量