Evaluation of the Efficiency of Parasitoid Wasp, Lysiphlebus fabarum (Marshall) (Hym., Braconidae), Reared on Aphis fabae Scopoli, Against the Melon Aphid, Aphis gossypii Glover

The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is one of the most important pests causes damage to vegetable both in fields and greenhouses. The biological characteristics related to the efficiency of natural enemies are considered as quality control indices for preliminary screening, prior to release of biological control agents. In this study some biological characters including parasitism rate, emergence rate, and sex ratio of a sexual strain of the parasitoid wasp, Lysiphlebus fabarum (Marshall), was evaluated for individuals that were reared on different stages of A. gossypii. Furthermore, important factors related to offspring fitness (body length, developmental time, fecundity, and longevity) were surveyed. Results revealed that, L. fabarum could successfully parasitize all the nymphal instars of the melon aphid. With the exception of egg size, all other characteristics were significantly affected by host stage. Wasps emerged from the second and third instars had higher fitness than the other stages. Conseuently, L. fabarum may be considered as an effective biological control agent of the melon aphid, although these results need to be confirmed by further field and greenhouse studies.