Relationship of Size and Development of Aphis cracciuora Koch (Aphididae) on Size, Development and Sex Ratio of the Parasite Aphidius colemani Viereck (Aphidiidae)

Abstract

Aplidius colenani is one endoparasitoid of Aphis craccovora. It can be used as a biological control agent against several aphids including Aphis spiraecola and Hyalopterus pruni. This study aimed to examine the effects of size and development stage of the host, on the size development and sex ratio fo the parasite. In general there was a negative relationship between the size and development stage of A. craccivora with the size and rate of development of A. Calemani. However, there appeared to be no measureable impact on the sex ratio of the parasite, the number of parasitised aphids or th enumber of emerging parasites. The successful development of the parasite in A. craccivora appears to be dependent not only on the stage of development of A craccivora, but also on the characteristics of the female parent of the parasite.