摘要 : Platygaster hiemalis Forbes is an egg-larval parasitoid of the Hessian fly, Mayetiola destructor Say, in the eastern U.S. Efforts to establish P. hiemalis in central Texas were unsuccessful following release of adult parasitoids o... 展开 Platygaster hiemalis Forbes is an egg-larval parasitoid of the Hessian fly, Mayetiola destructor Say, in the eastern U.S. Efforts to establish P. hiemalis in central Texas were unsuccessful following release of adult parasitoids over 3 years. From 1991-94, ca 61,000 adult P. hiemalis were released in fields of wheat, Triticum aestivum L., naturally infested with Hessian fly in Clay, Bosque and Milam Counties, Texas. Parasitism by P. hiemalis of Hessian fly puparia collected from these sites ranged from 0.3 to 1.1% while releases were being made. P. hiemalis was not recovered at any of the three locations after releases were discontinued. Populations of P. hiemalis established in field cages in the spring did not survive to the following spring in central Texas. Laboratory studies found that P. hiemalis did not complete development at 30 degrees and 35 degreesC, but died as larvae, pupae or adults inside the host puparium. In contrast, Hessian fly developed to the adult stage or diapaused in the larval stage at 30 degrees and 35 degreesC. Results suggest that high temperatures during the summer in central Texas may be lethal to P. hiemalis. 收起