چكيده لاتين :
THE EFFICIENCY OF THE ECTOPARASITOID Diglyphus isaea WALKER (HYMENOPTERA: EULOPHIDAE) ON THE SERPENTINE LEAFMINER Liriomyza trifolii (BURGESS) IN TOMATO GREENHOUSES
Natural abundance of the ectoparasitoid Diglyphus isaeaWalker was studied
in four tomato greenhouses at Sakha, Mehalla Al-Kobra, and Metobus. The parasitoid
showed low populations in March, then developed good populations that kept the
populations of the serpentine leafminer, Liriomyza trifolii at low densities till the end of
the season in all studied greenhouses.
D. isaea recorded two peaks of abundance in three of the greenhouses, the
highest peak recorded 21, 36, 28 and 31 individuals/ 50infested leaflets in
greenhouses 1, 2, 3 and 4, respectively . The highest average numbers occurred in
April in all greenhouses recording 18 ± 2.9, 24.3 ± 8.3, 23.0 ± 5.2 and 26.0 ± 5.2
individuals/ 50infested leaflets in greenhouses 1,2,3 and 4 ,respectively. On the other
hand, the percentage of parasitism ranged between 17.8 ± 0.9 and 47.3 ± 1.3%
recording its highest numbers in May in greenhouse 1 (43.3 ± 5.3%), and in April in
greenhouses,2,3 and 4 recording 46.4 ± 5.1 , 43.6 ± 2.3 and 47.3 ±1.3% ,
respectively. The percentage of killed larvae according to host-feeding recorded its
highest monthly average numbers in May in greenhouses 1, 2 and 3 (43.5 ± 5.3 , 29.0
± 9.2 and 24.0 ± 7.3% respectively) and in June in greenhouse 4 recording 30.6 ±
6.4% .