谷实夜蛾成虫的形态鉴定

Identification of corn earworm Helicoverpa zea

进境植物检疫性有害生物谷实夜蛾与棉铃虫在外形上极为相似。本文通过分析雄成虫5个主要鉴别特征:抱器瓣、阳茎端膜支突数量、阳茎端膜拉伸后的盘管数量、阳茎端膜上的阳茎针数量和第8腹板端部形态,为准确鉴定谷实夜蛾提供科学依据。把虫样浸泡在10%NaOH中18～24h,然后解剖雄性外生殖器,测量抱器瓣长度,若长度大于5mm则可判定为谷实夜蛾;否则需结合其余特征做进一步鉴定。

The Corn earworm,Helicoverpa zea is very similar to the Old World bollworm,Helicoverpa armigera（Hübner）in morphology.In order to accurately indentify corn earworm,this paper anylyzes the eighth sternite and male genitalic characters.Samples should be placed into 10% NaOH for 18~24 hours.After dissection,the valva is measured.If it is longer than 5mm,it is identified as H.zea;otherwise more characters should be checked.