三化螟、二化螟及大螟成虫的飞翔能力

本文利用飞行磨(Flight mill)装置对三化螟Tryporysa in certulas(Walkr) 二化螟 Chilo suppressalis(Walker)；及大螟Sesamia infirence(Walker)成虫的飞行能力进行了测试，结 果表明：三化螟与二化螟成虫的飞翔能力基本一致，其有效飞行日龄均为4天，成虫羽化后无明显的生殖前期(<1天)，卵巢发育为II级时(1日龄)飞行能力最强。最远累计飞行距离可达32公里以上。雌雄虫具有不同的持续飞翔能力。大螟是这三种螟虫中飞翔能力最强的一种，具有极强的持续飞行能力，雌、雄虫可分别达32与50公里以上，大螟的有效飞行日龄一般为6天，且具有2-3天的生殖前期，卵巢发育为II级时飞翔能力最强，随日龄的增加，飞翔能力逐步下降，大螟成虫具有远距离扩散飞翔能力及一定的迁飞生理行为基础。

THE FLIGHT CAPABILITIES OF RICE STEM BORER MOTHS TRYPORYZA INCERTULAS, CHILO SUPPRESSALIS AND SESAMIA INFERENS

Adult flight capabilities of three major rice stem borers, Tryporyza incenulas, Chilo sup-pressalis and Sesamia inferens were determined with flight mill and computer system. The results show that the moths of T. incenulas and C. suppressalis have similar flight capability. Normal flights took place within four days after emergence, and they had no conspicuous pre-repro-ductive period and calling and mating could occur whithin 24 hours after emergence. Moths within one day after emergence in the second phase of ovarian development had the strongest flight capability. The cumulative flight distance of a female moth was determined to be over 32 kilometers. Female moths showed longer flight duration while most of the male moths made irregular interval flights affected easilty by physical conditions. Flights of thse two species were closely related to calling, mating and oviposition behaviours, showing typical mating-flight syndrome. Though most flights in the field were trivial, the longest dispersal distance could be over 100 kilometers. The moth of S inferens had the strongest flight capability among the three rice stem boreres and the flight distance of female and male moths were over 3- and 50 kilometers, respectively. Normal flight conld occur during the first six days of adult life. The pre-reproductive period were two to three days. Adults in the second phase of ovarian development made the longest flights. Thier flight capability declined with the development of the ovaries. This species has flight capability of long distance dispersal and possesses phy-siological and behavioural bases of migration flight.