فریبا سهرابی

The influence of intraguild predation between Orius albidipennis Reuter and two parasitoids, Eretmocerus mundus Mercet or Eretmocerus eremicus Rose and Zolnerowich, on the suppression of Bemisia tabaci Gennadius was investigated under laboratory conditions. Through a non-choice test, the 2nd and 3rd instar nymphs of B. tabaci and larval and pupal stages of both parasitoids were offered separately to both 5th instar nymphs and adults of O. albidipennis. In the choice test, various combinations of parasitized and unparasitized preys were provided for two stages of O. albidipennis, and their preference was recorded. Both predator stages readily preyed upon unparasitized and parasitized nymphs of B. tabaci. The most predation of O. albidipennis adults occurred on E. eremicuslarvae, while for the 5th instar nymphs, it was recorded on E. eremicuslarvae and pupae. The least predation of both stages was recorded on unparasitized nymphs of B. tabaci and E. mundus pupae. None of the prey combinations showed any obvious preference of adults and the 5th instars of O. albidipennis toward parasitized or unparasitized prey.