Superparasitism in Trichogramma evanescens minutum Riley, an egg parasite of sugarcane and maize borers in India. II. Causes of superparasitism (Hymenoptera: Trichogrammatidae).

Abstract

1. Experiments were conducted to find out the factors that resulted in superparasitism in Trichogramma evanescens minutum Riley when mass multiplied on the eggs of Corcyra cephalonica Stainton under laboratory conditions. - 2. Very little superparasitism occurs if a sufficient number of host eggs are available for oviposition. Trichogramma has a well developed discriminative ability. - 3. When there is a scarcity of host eggs, and when the parasite is exposed to a limited number of eggs for long periods, the restraint breaks down and the pysiological urge to oviposit results in superparasitism. - 4. The restraint exercised by Trichogramma is not perfect, and the ability to maintain it varies from one individual to another.