Evaluation of Biological Control of Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) using Diglyphus isaea (Walker) (Hymenoptera: Eulophidae) in Three Seasonal Culture Types of Tomato Greenhouse
Biological control of Liriomyza trifolii (Burgess) using Diglyphus isaea (Walker) has been evaluated in tomato greenhouse, for three seasonal culture types: spring type (March-July), summer type (June-October) and autumn type (July-December). For spring type, totally 5.8 individuals/㎡ of D. isaea has been released at six times from late April, when the density of L. trifolii was about 1.0 individuals/plant. Corrected mortality of Liriomyza trifolii caused by parasitoids was 97.6% at early July, and the proportion of D. isaea was 88.9% of all parasitoids collected in the greenhouse. In the case of summer type, totally 1.8 individuals/㎡ of D. isaea has been released at five times from early July, when the density of L. trifolii was about 0.4 individuals/plant. Corrected mortality of L. trifolii caused by parasitoids was 84.4% during the whole season, but the proportion of D. isaea was very low (only 13.8%). Immigrating parasitoids such as Chrysocharis penthus were synchronized to control the leafminer in the greenhouse. For autumn type, totally 2.7 individuals/㎡ of D. isaea has been released at four times from mid September, when the density of L. trifolii was about 0.7 individuals/plant. Corrected mortality of L. trifolii caused by parasitoids was 85.7% at mid December, and the proportion of the D. isaea was 83.4%.