摘要
河南省驻马店地区属我国粘虫一代常发区。根据1975～1989年在上蔡和新蔡县的田间多点调查,证明中华卵索线虫是粘虫幼虫的重要寄生天敌。58％的点对粘虫的寄生率达40％以上,最高超过90％。被寄生的粘虫食叶量平均减少38％。在18～20和22～27℃室温下,14天和8天后死亡。1984年为粘虫大发生年,上蔡县东岸村麦田粘虫密度达30.3～119.5头/m^2,由于线虫寄生率高达35.0～45.5％,未进行化学防治,小麦被害很轻。根据1979～1985年资料初步分析,线虫对一代粘虫常发区(新蔡县)的自然寄生率与二代粘虫常发区(锦州、公主岭、哈尔滨市郊)6月份诱蛾数有较显著的负相关,说明采取措施,保护利用中华卵索线虫,对压低粘虫迁飞基数是可行的。当地4月下旬至5月中旬的雨日、降水量和相对湿度是影响线虫对粘虫寄生率变动的主要因子。
The 1st generation armyworm, Mythimna separata, commonly occur in Zhu Ma Dian Prefecture, Henan Province in Central China. Field studies during 1975-1989 in Shangcai County and Xincai County of the prefecture confirmed that Ovomermis sinensis is an important parasitic natural enemy of the arnyworm. The average parasitization rate was over 40% with the highest reaching 90%, in 58% of the observation sites. Feeding capacity of the infected larvae reduced by 38% in average. In the laboratory of 18-20℃ and 22-27℃, the infected larvae died 14 and 8 days, respectively, after infection. During an outbreak of the armyworm in 1984, when the larval population density was 30.3-119.5 larvae/m,2 in wheat fields,of Dongan Village, Shangcai County, the natural larval parasitization by the nematode was 35-45.5%. The defoliation of wheat was minimal with no pesticide application. Results of a data analysis for 1979-1985 realed a significant negative correlation between the natural parasitization of the pest in its first generation occurring area (e.g. Xincai County) and the number of trapped adults in its second generation ;curring area (Jinzhou, Gongzhulipg, Harbin of northeast China). -It indicated that suppression of the first generation armyworm population by conservation of the nematode may contribute to reduction of the initial population 'level of the migratory armyworm. In Zhu Ma Dian area, number of raining days, precipitation rate and relative humidity during late April to mid May were found to be the main factors influencing the fluctuation of armyworm parasitization.
基金
农业部全国植保总站的资助
关键词
中华卵索线虫
线虫
粘虫
控制
天敌
Ovomermis sinensis Mythimna separata conservation wheat pest natural control
