The efficenciy of the parasitoid Bracon hebetor (say) (hymenoptera: Braconidae) in densities and releas periods time on potato tuber moth phthorimaea operculella (zeller) (Lepidoptera :Gelechiidae) in Lab.

Abstract

A series of experiment were conducted in Biocontrol Technoloegy lubs. of Technical college/ Musaib . and The insects lab. of Science and Technolagy ministry during The period up 2013-2014 included breeding of phthorimaea operculella (zeller) using potato tubers as afood to obtain enough numbers of the inssct individuols in diffirent phase to carry out some trials implicating the parasite Bracon hebetor (say) using some insecticide in their control with their estimation of their field density and their food preferability of some economic crops of solanceae The results may be summarized as follow:- An increase in egg no. for the parasit B. hebetor and its larvies and pupies with the increase of exposure time of the host larvies to the parasite after 24, 48 and 72 hours .parasitic efficiency was affected by host density and it increased with the increase of the density. When host density was (10) larvies and the sexual percent is 1:1 male to female the least larvies no. reached 3.75 after 24 hours, and at was zero for egg no. and larvies no. and puppies no. of the parasite and sexual percent after 24 hours. On the other hand when the host density was (10) larvy and the sexual percent (5:5) male to female the included larvy mean of the host reaches 9.75 and higher egg mean 20.25 and higher mean of the parasit larvy 17.75 and the highest pupy no. 13.75. the deviation of the sexual percent was for the favour of the male (1.75: 0.75) after 72 hours. When the host density was (50) larvy and (1:1) is the sexual ratio, the last larvy mean 17.75 reached after 24 hours, and reached zero for egg mean and parasit larvy mean and puppies of the parasit and well on the sexual ratio after 24 hours, but when the host density was (50) larvy and the sexual ratio of the parasite (5:5) the highest larvies mean 47.00 , higher egg mean 98.50 ,higher larvies mean of the parasit 88.50, the highest larvy mean of the parasit 69.25 as well on the deviation of the sexual ratio the parasite to the favour of the male (8.50:4.25) male to femal reached after 72 hours.