الفهرس 
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Abstract
Study was carried out in laboratory and the experimental field, Environmental Studies and Research Institute, Minufiya University, El-Sadat Branch, Egypt during two successive seasons
2008 and 2009 on potato crops (Solanum tuberosum L), to determine the most preferable host (Sitotroga cerealella and Phthorimaea operculella), suitable egg age (1,2,3 and 4 days age) and
favorite temperature (20,25 and 30°C) for mass production the egg parasitoid Trichogramma evanescens under lab., condition and study the effect of different T. evanescens releases rate
(40,000 , 80,000 and 120,000) parasitoid/fed, bio-agent ( Protecto 10% WP 300gm/fed) and natural compound (Tracer 24% SC 30ml/100L) versus the insecticide (Selecron72% 750ml/fed),
against Ph. operculella under field condition during 2008 and 2009.
The results are summarized as follow:
Statistical analysis indicated no significant differences between two hosts in both choice and no choice case for all tested biological aspect. The 25°C was the most suitable temperature for the all tested biological aspects, gave highest value of (no. of parasitized egg and its rates, no. of
emerged egg and its rate) beside recorded a moderate value of total duration period at all. Total developmental period showed inversely related with increase temperature for both tested host at all. Results showed shorter duration period of the parasitoid in free choice case than in no choice case. The interaction between egg species and temperature showed no significantly effect on (no.
of parasitized egg, no. of emerged egg), in both choice or no choice. The oldest age (4 days age) and highest temperature (30°C) seemed to be not suitable condition for mass production Tevanescens in both choice and no choice tests for two tested hosts, gave lowest parasitism and emergence, while the youngest age (1 day age) with 25°C was the favorite condition and most
effective for rearing the parasitoid on either S. cerealella and Ph. operculella at all, recorded highest rates of parasitism and emergence. Under field condition, data indicated highly significant differences between the control and the other six studied treatments for inducing the potato tuber infestation in both seasons. The 4th releases of wasps at rate 120,000 parasitoids/fed was the best treatment and most effective comparing with the other tested treatments, whereas
gave the lowest mean value of [(infested tuber, holes, developed pupae, and emerged moth) (8.33
& 9.33), (11.33 & 14.00), (9.67 & 12.00) and (7.67 & 9.67)], for the previous traits in both years, respectively as well as highest yield (9.65 and 9.37) ton/fed with lowest value of losses due to PTM infestation (35.33 and 37.0) kg/ton in both seasons, respectively. The natural compound Tracer 24% occupied the third degree of efficiency in reducing PTM infestation. The bio-agent Protecto 10% gave moderately effect for minimizing potato infestation. The chemical insecticide Selecron 72% seemed to be the worst one for the same criteria.