Body size classification of the egg parasitoid Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

Parasitoid body size has been used as an indicator of fitness and its capability to parasitise hosts in the field, but studies that have investigated this relationship have disagreed. In the present study, we investigated the relationship between the two most common body parts used in body size classification and tried to select groups of small and large parasitoids by discriminant analysis. We found that groups with small or large individuals differ from each other only when the two body parts were used to classify them. We conclude that using just one body part to estimate the size of Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) could be misleading and that caution is needed when defining small and large individuals.