STUDIES ON SOME INSECT NATURAL ENEMIES ASSOCIATED WITH THE CITRUS LEAFMINER, Phyllocnistis citrella Stainton (LEPIDOPTERA : GRACILLARIIDAE)

Studies on the natural enemies attacking the citrus leafminer (CLM), Phyllocnistis citrella, Staintonwere carried out in a neglected citrus orchard during two successive seasons 1996/97 and 1997/98 in Dakahlia Governorate.
During the course of the study, no parasitoids on CLM eggs were recorded. Four parasitoid species of family Eulophidae were recorded on CLM immature stages (larvae, prepupae and pupae). They are two elachertin parasitoids namely, Cirrospilus pictus (Nees) (the most important primary ectoparasitoid) and C. quadristriatus (Subba Rao & Ramamani); an eulophin, Pnigalio sp. and the fourth one, Baryscapus sp. (the less important parasitoid). Chrysopa carnea, Steph. seems to be an important predator attacking CLM immature stages under field conditions.
C. pictus and Pnigalio sp. populations showed three peaks annually. C. quadristriatus was recorded rarely with few numbers (during September). In the second year, it appeared regularly, the population showed two peaks of abundance.
There are a good synchronization between the parasitoids (C. pictus and Pnigalio sp.) and its host populations. While, the synchronization was not good with C. quadristriatus.
In respect to the sex ratio: the number of parasitoid females production outnumbered that of males. There are a negative response of female production of C. pictus and C. quadristriatus with the increase of temperature or relative humidity. While, daily relative humidity exhibited a significantly  positive effect on Pnigalio sp. females production.
The regression analysis indicated that the parasitization values of parasitoids showed a density dependent response to the increase of host density.