Host-instar selection, interspecific competition, and reproductive capacity of extant and novel parasitoids (Hymenoptera: Braconidae) on Egyptian cotton leafworm

Cotesia marginiventris (Cresson) and Microplitis rufiventris Kok. parasitize young instars but differ in their degree of host selection instar of Spodoptera littoralis (Boisd.).Brood sex ratio (proportion of females), realized lifetime fecundity, and clutch size were relative positively to instar preference, 2nd instar for C. marginiventris, and 3rd instar for M. rufiventris.Extrinsic competition occurs between the two species, and M. rufiventris is typically the superior of the two species. Some parasitized hosts resulted from parasitization by single wasp species, produced no parasites and showed intrinsic completion