重阳木斑蛾的生物学及防治研究

重阳木斑蛾是重阳木的一种最重要害虫。此虫在福建福州常间歇性猖獗发生为害,一年发生四代,一至三代严重害叶。以不同龄期的幼虫在枝干裂缝、木栓层下及粘叠的叶片间越冬,极少数化蛹越冬。冬季气温达8℃以上时,越冬幼虫仍能少量取食,无明显的仃育。成虫产卵于枝干皮下,卵期6—15天。幼虫共6—8龄,幼虫期33—34天(第1—3代)及137天(第4代,即越冬代);蛹期10—20天;成虫寿命长者13天。本文对各虫期形态和生活习性有较详细的记述。天敌有:卵寄生蜂;绒茧蜂Apanteles sp.和另一种茧蜂及日本追寄蝇Exorista iaponica T.-T.等两种寄蝇寄生于幼虫;横带沟姬蜂Goryphus basilaris Holmgren寄生于蛹。人工捕杀、清洁园地、保护天敌和喷撤六六六等农药,防治效果都很好。

A STUDY ON THE BIONOMIC CHARACTERISTICS AND CONTROL OF THE BISCHOFIA BURNET HISTIA RHODOPE CRAMER

The Bischofia burnet, Histia rhodope cramer, is one of the most destructive insects of the useful shade tree Bischofia trifoliata Hook in Fuzhou Fujian province. The life history and biological characters of this insect has been worked out. It propagates four generations a year in Fuzhou and overwinters with various instar larvae either in the crevices of twigs and the trunk, or under the cork of the stem. Occasionally only very few pupae are overwintered. Most of the larvae became active, if the air temperature raised higher than 10℃ in winter. No remarkable phenomenon of hibernation was found. Eggs are laid under the bark of the trunk and twigs. According to our breeding records, the eggs hatched from 6—15 days in the various generations found. The larva maintains six to eight instars. As a general, the larval period lasted about 33—34 days, while the winter generation lasted as long as 137 days. The length of the pupal stage is 10—20 days. The adult life lasted 13 days at maximum. Natural enemies of this pest consist of: egg-parasites (ind.); Apanteles sp.; another braconid; the tachinid, Exorista japonica T.-T. (in larvae); and the ichneumonid Goryphus basilaris Holmgren (in pupae). Preliminary investigations on control were conducted. Sanitation of the environment, hand—picking or spraying with 666 on the appearance of the early instar larvae are very effective measures.