تربية و إكثار متطفلا البيض Trichogramma evanescens Westwood و (Hym. : Trichogrammatidae)‎ T. oleae)‎ Pintureau

Abstract EN

This study was conducted using the egg parasitoids, Trichogramma evanescens Westwood and T.

oleae Pintureau to evaluate their preference to the factitious hosts, Ephestia calidella (Guenee) and E.

cautella (Walker) eggs; and to investigate the influence of temperatures of 14, 22, 25, 28, 30, 33 and 35 C, at 60±5% RH and 16 hr light/day on some biological characteristics of both parasitoid species.

The results indicated that host egg preference of the two T.

evanescens groups depend on the type of host egg that the parasitoid generations were reared on.

The highest fecundity of 117 eggs/ female was recorded at 25 C for T.

evanescens and 40 eggs/ female at 22 C for T.

oleae.

The estimated optimal temperature for fecundity was around 24 C and 19 C, for T.

evanescens and T.

oleae, respectively.

The results showed a slight difference in adult emergence for both parasitoid species at different temperatures tested, except at 35 C, where no emergence occurred.

Results also indicated the presence of variable effects of temperature on developmental periods of the parasitoids.

The relation between temperature and development duration of both species was calculated: the minimum and maximum thermal thresholds for development of T.

evanescens were around 9 and 37 C and for T.

oleae were 9 and 38 C.