TRICHOGRAMMA EMBRYOPHAGUM HARTIG تاثير نوع ميزبان آزمايشگاهي روي پارامترهاي رشد جمعيت زنبور پارازيتوييد

The effect of the type of laboratory host on the population growth parameters of Trichogramma embryophagum Hartig (Hym, Trichogrammatidae)

The population growth parameters of Trichogramma embryophagum Hartig on the eggs of Ephestia kuehniella Zell and Sitotroga cerealella Oliv at T 25 ± 1° C, RH 50 ± 5% and photoperiod 16:8 (L: D) hours were compared. In both experiments, 150 density of related host eggs plus honey solution were located into test tubes for 24 hours beside a fertile female wasp. After 24 hours the above-mentioned eggs were replaced with another eggs. This process continued to be repeated every 24-hour until the wasp died. This study had 40 replications. The reproduction rates including gross and net reproduction rate in wasps reared on S. cerealella (Te-S) were 41.76 and 37.63, and in wasps reared on E. kuehniella (Te-E) were 55.24 and 48.88, respectively. The intrinsic rate of increase (rm), finite rate of increase (A ), mean generation time (T) and doubling time (DI) were 0.2184, 1.2441, 16.487 and 3.174, in Te-S wasps and were 0.2376, 1.2683, 16.367 and 2.917, in Te-E, wasps respectively. Thus, it can be inferred that reproduction rates and growth rate are larger in Te-E wasps than Te-S wasps, but growth time was less than that of Te-S wasps. The results revealed that in Te-S and Te-E wasps 95 and 96 % population respectively were immature, and the rest, that is 5 and 4% respectively, were mature insects and their cooperating role being gradually decrease from early oviposition period on. In other words, mature insects played less important role in stable population. Therefore it can be claimed that adult insects in the Te-S wasps played more important role in stable population than Te-E wasps.