沟眶象的生物学特性及行为观察

沟眶象Eucryptorrhynchus chinensis(Olivier)是臭椿林木的主要害虫之一。在宁夏银川地区该虫1年发生1代,世代不整齐,以成、幼虫越冬。卵期7~10d,幼虫共有6龄,化蛹时间为4月下旬至5月和7月下旬至8月上旬,蛹经过10~14d羽化为成虫。成虫主要啃食椿树枝条幼芽和韧皮部,幼虫危害衰弱木,有时危害生长健旺的幼树韧皮部或木质部。成虫具有假死性,喜光,活动高峰在11~17时。雌、雄虫间的单次交配时间可持续10~20min;有重复交配现象,交配的时间间隔大约是20~40min;交配结束后,雄虫仍伏于雌虫背上达20~30min。雌虫蛀孔产卵,每产1粒卵约需15min左右,每雌平均产卵40粒左右。

The biological characters and behavior of Eucryptorrhynchus chinensis

Eucryptorrhynchus chinensis (Olivier) is one of the most important pests of Ailanthus trees. The morphology, living habits, life cycle and behavior of the pest is described. There is one generation per year. Both adults and larvae hibernate in soil and generations overlap. The eggs last 7～10 days. The larva has six instars. The execrate pupa appears from the end of April to May, the end of July to early August and adults emerge after 10～14 days. The adult weevils feed on tissues of bud and phloem by the long beak .The young larvae feed on tissues of liber and the elder larvae bored in layer of wood. The adults had thanatosis and phototaxis habit and the peak of daily activity was 11:00～17:00. Female and male adults can mate repeatedly and each copulation lasted 10 to 20 min. About 20 to 40 mins later, they can mate again. After the copulation, the female could feed with the male mounted on back for 20 to 30 mins. The females gnawed a hole in the bark and laid an egg in about 15 min. On average, one female laid about 40 eggs in the reproductive period.