黔中稻区二化螟的越冬幼虫虫口密度及其自然寄生率

Overwintering Population Density and Parasitism of Chilo suppressalis in Central Guizhou

为准确预测预报黔中稻区二化螟越冬后的发生提供理论依据,采用GB/T15792—2009稻桩剥查法对贵阳市花溪区、安顺市平坝县、黔南州惠水县和黔东南州麻江县等稻区二化螟越冬幼虫虫口密度及自然寄生情况进行调查。结果表明:麻江县的越冬幼虫虫口密度最高,达15 741头/667m2;其次为平坝县和惠水县,越冬幼虫虫口密度分别为10 684头/667m2和10 153头/667m2;贵阳市花溪区的越冬幼虫虫口密度最低,仅944头/667m2。大多数地区的雌雄蛹重量有显著差异。调查共采集到5种寄生蜂,包括稻螟小腹茧蜂、螟甲腹茧蜂、大螟钝唇姬蜂、菲岛抱缘姬蜂和黄眶离缘姬蜂;各稻区的寄生率均较低,平坝县二化螟幼虫被寄生率最高,达15.6%,其次为麻江县14.6%、花溪区6.7%和惠水县5.7%。

Aimed to provide the reliable forecasting information for C.suppressalis occurrence in central Guizhou area in the next year,a Stubble-Scraping method of GB/T 15792-2009 was employed to investigate the overwintering population density and parasitism of C.suppressalis in four counties located in Central Guizhou,namely Huaxi,Pingba,Huishui and Majiang.Results：Overwintering larval density in Majiang was the highest（15 741individual/667m2）among the four counties,the larvae density in Pingba and Huishui fields were 10 684individual/667m2 and 10 153individual/667m2,respectively.The larvae density in Huaxi field was the lowest,only 944individual/667m2.The female＇s pupal weight was significantly higher than male＇s pupal weight in most fields,except for the larvae collected from Huaxi fields.There were five species of parasitods collected in total from this investigation,including Microguster russata,Chelonus munakatae,Eriborus terebranus,Temelucha philippinensis and Trathala flavoorbitalis.The parasitism rate of overwintering C.suppressalis was the highest in Pingba（15.6%）,followed by Majiang（14.6%）,Huaxi（6.7%）and Huishui（5.7%）.