环渤海湾地区棉铃虫成虫的卵巢发育特点及与迁飞行为的关系

Ovarian Development of Adult Females of Cotton Bollworm and Its Relation to Migratory Behavior Around Bohai Bay of China

1 996～ 2 0 0 0年期间先后在河北省廊坊市、北京市西郊和辽宁省辽阳市系统研究了不同代别棉铃虫成虫的卵巢发育特点及与季节性迁飞行为的关系。研究结果表明环渤海湾南部的河北省廊坊市和北部的辽宁省辽阳市第 1代棉铃虫成虫种群主要由外地迁入 ,第 2～ 3代种群多数年份主要来源于当地 ,但部分年份亦有外地种群大量迁入。北京市西郊空中诱捕的棉铃虫 1～ 3代成虫多为产卵前期个体 ,具迁飞昆虫的生殖生理特征 ,表明棉铃虫成虫迁飞活动存在于各个代别。

The Cotton bollworm, Helicoverpa armigera (Hünber), is one of the most important agricultural pests in China. Its seasonal migration, together with the ability in facultative diapause, is responsible for its pest status in different climatic regions. The region around Bohai Bay, where cotton bollworm occurs seriously in most of the years, is a major area for cotton and corn production in China. Therefore, it is extremely important to conduct experiments in the area on migration of cotton bollworm so that we can have better understanding of the general migration principle of the pest. Here reported are the research results on ovarian development of adult cotton bollworm females captured in Bohai Bay and its relation to migratory behavior of cotton bollworm. The experiments were conducted from 1996 to 2000 in Beijing and Langfang City of Hebei Province, and Liaoyang City of Liaoning Province, which respectively located in south and north parts of Bohai Gulf. One 300W ground lighttrap was used to monitor adult dynamics of cotton bollworm in Langfang, and a 300W searchlight trap were set up in the top of a building (25 meters high) at Institute of Plant Protection, CAAS, in western suburban of Beijing for sampling insects from high altitude. In Liaoyang, a trap based on wilting poplar was designed to attract the adults of cotton bollworm. The population dynamics of cotton bollworm moths were monitored from early June to early September. The number of H. armigera adults caught in the traps were recorded each day, and the females were sectioned and graded according to ovarian development. The relationship between moth origin and developmental grade of their ovary was analyzed with the method described by Chen et al. and Li et al .Three generations occur for this pest in Bohai Bay area each year. The results indicated that the first generation moths in both Langfang and Liaoyang, immigrated from middle or southern part of northern China, and the second or third generation moths originated mainly in local sites in most years while the moth immigration still occurred. The moths captured with a light trap from high altitude, in whole season in west suburban area of Beijing, showed that most of them were at pre-mature stage, implying that they possessed the physiological characteristics of migrating insects. Therefore, it is concluded that the migratory activities of cotton bollworm moths could take place in every generation.