The Effect of Host Density and Viability on Superparasitism Behavior of Trichogramma cacoeciae and T. principium Females

Non-choice laboratory experiments were conducted to estimate the influence of host density and viability of codling moth eggs on the superparasitism behavior of Trichogramma principium Sug. et Sor and T. cacoeciae Marchal (Hymenoptera: Trichogrammatidae). There was a strong effect of number of emerged offspring of T. principium and T. cacoeciae and host density on the mean number of parasitized eggs. The tendency of T. principium and T. cacoeciae females to oviposit was increased when high number of Cydia pomonella was available. The results presented that the host density influenced in the percentage of superparasitized eggs. The superparasitism appeared to be more noticeable when sterile C. pomonella was offered. Superparasitism behavior was noticed in both parasitoids species, regardless of host density and viability. The study demonstrates the success of T. principium and T. cacoeciae in the existence of high host density and in an integrated program employing the sterile insect technique for C. pomonella management