Agromyzid Leafminers and Their Parasitoids on Vegetables in Northern Vietnam

Abstract

Leafminers (serpentine leafminers), Liriomyza spp. (Diptera: Agromyzidae) are serious insect pests that attack many vegetable crops and wild plants. Field surveys were conducted in 6 provinces of northern Vietnam during 2004-2006 with the aim of recording leafminer species, their parasitoids and seasonal dynamics of leafminers on vegetable crops. There are 31 species of host plants of Liriomyza spp.; tomato, French bean, longbean, cucumber and sweet brassica are seriously attacked. Leaf damage at harvesting period is very high, at about 85–90%. Seven leafminer species found were Liriomyza sativae, L. chinensis, L. bryoniae, Liriomyza sp., L. katoi, Chromatomyia horticola and Phytomyza sp. Liriomyza sativae is the most abundant species which infested 23 out of the 31 vegetable and wild plant species, followed by Liriomyza sp. In addition, fifteen hymenopteran parasitoid species associated with the leafminers were found. Among them, Neochrysocharis formosa and Chrysocharis pantheus were abundant species. In spring, the incidence of infestation by leafminer on tomato, French bean and yard long bean increased from the start to the end of the season. The percentage of parasitism varied according to plant stage and leafminer density.