EFFECT OF HOST AND PARASITOID DENSITY ON the EFFICIENCY OF TRICHOGRAMMA EVAN ESCENS (WESTWOOD) AND TRICHOGRAMMA BRASSICAE(BEZDENKO) (HYMENOPTERA: TRICHOGRAMMATIDAE ) MANAL A. A. EL SHARKAWY

Studies were caned out at Plant Protection Resmrdi Institute in 2005 to find out the effect of if fferent host and parasitoid density levels on the efficiency of Tnichogranana evanescent and T. brasticae Eggs of pink bolhvorm, PeNOTOWidra posoceerlie (Saunders) (Lepict•ptaa: Gelechigae were used as a host for the two Triebogramma seg. Three deferent host densities v2., 150, 300 and 600 eggs of P. 905Volella were provided to 2, 4, and 8 females of the two parasitoid species, respectively in glass vials (4)(8.5 an). The highest percentage of parasitism was obtained when T. evanescent and T. brassir.ae densities were 8 females and introduced 150 P. gossypielia eggs. The percentages of parasitism were 95.27 and 94.27% for the two parantord species, respectively. Whereas, the lowest percentage of parasitism was obtained when the parasitold density was 2 females and introduced 600 host eggs, as it was 13.86% for T. evanescent and 15.96% for T brassicae In case of T. evanescent, emergence percentages were statistically similar in al treatments and was above 91.73%. Whereas, emergence percentage of T. brassicae was decreased to 88.24% when the parasdold density was 2 females/vial. Female ratio er offscing was higher (67.06%) when T. evanescent density was 2 females and decreased insignificantly to 64.84 and significantly to 59.16% when permit,* density Increased to 4 and 8 female/ vial, respectively. As for, T. tvassicae, percentages of produced females were insignificantly different in all parashoid densities. The percentage of super parasitism was artless or negligible at al T evanesces densities as, it didn't heighten 2.56%. While T. bra.vicae females eihibited significantly higher percentage of super parasitism (4.58%), when introduced only 150 eggs for all parasitcid densities compared with all other treatments.