桃蛀螟越冬幼虫重量、死亡和羽化的调查研究

Studies on the Weight, Death and Emergence of Overwintering Larvae of Dichocrocis punctiferalis Guenee

2003～2004年对桃蛀螟越冬幼虫的重量、死亡和羽化情况进行了调查研究。桃蛀螟已成为玉米田的优势种害虫,越冬幼虫的重量大部分在100～180mg之间,而越冬前死亡大部分集中在110mg以下,死亡原因主要是由于感染病毒、真菌以及低温等的影响。随着桃蛀螟越冬幼虫重量的增加,越冬羽化率升高,130～160mg重量段是桃蛀螟越冬幼虫羽化的一个临界点,在此重量段以上的桃蛀螟58%能够羽化,是次年桃蛀螟的主要虫源。

The weight, death and emergence of overwintering larvae of Dichocrocis punctiferalis Guenee was studied in 2003～2004. Dichocrocis punctiferalis was the dominant pest in corn fields. The weight of overwintering larvae ranged mainly from 100mg to 180mg, while the death rate weighing under 110 mg before overwintering was relatively high, and the main causes were virus inflection,fungus inflection and low temperature. The emergence rate of overwintering larvae rose as the increase of their weight. The weight between 130mg and 160mg was a critical point, above which about 58% Dichocrocis punctiferalis Guenee could emerge, thus becoming the main source of pests next year.