dc.description.abstract | Studies on Leaftniner Liriomyza spp. in Green Onion Fields, and ParasiJoid Opiu. chromatomyiac Belokobylskij & Wharton (Hymenoptera: Bracon/dae). Field studies were conducted to detennine population abundance ofleafminers and their parasitoids in green onion fields in Puncak, West Java. In addition to that, laboratory studies were carried out to determine demographic parameter of Opius chromatamyiae as well as response of parasitoid to increasing host density. Results revealed that green onions were infested by two species of leafminers, Liriomyza huidobrensis and Liriomyza chinensis. Leafminer flies emerged from Erwor leaves (54.5) were significantly higher than those ofRP leaves (18.65) (P ~ 0.0005). However, number of leafininer flies caught on sticky traps was not statistically different (P ~ 0.297). Two species of parasitoid, Hemiptarsenus varicornis and 0. chromalomyiae. were associated with leafininers in green onion fieJds. Higher number of parasitoids emerged from Erwor leaves (13 .68) as compared to RP (6.90) (P 9>.0007 ). However, level of parasitization were 24.36% on Erwor and 28.45% on RP, and was not significantly different (P ~ 0.387). Laboratory studies indicated that net reproduction (Ro) of 0. chroma/omyiae was 28.55, generation time (T) 15.96 days, intrinsic growth rate 0.21, and total of reproductive value 223.64. The stable age distribution ofparasitoid were 37.93% eggs, 24.92% larvae, 20.36% pupae and 16.78% adults. The parasitoid showed functional response type II to increasing host density, with a ~ 0.08 and Th ~ 2.58. | en |