IPM Packages for Crops

insect pests

INSECT PESTS

Onion thrips [ Thrips tabaci (Thysanoptera: Thripidae)] A polyphagous pest feeding on more than 300 plant species. Thrips feed on leaves by rasping and sucking cell contents causing silvery sheen or streaks on leaves. Several topsoviruses, such as Iris yellow spot vi- rus, are transmitted by onion thrips and are responsible for serious economic losses. Beet armyworm [ Spodoptera exigua (Lepidoptera: Noctu- idae)] A major pest on vegetable crops with a wide host range. Young larvae feed inside the leaves, leaving only the outer cuticle and causing a characteristic “window-pan- ing” on leaves. Army worm [ Spodoptera litura ((Lepidoptera: Noctu- idae)] A polyphagous pest that feeds on wide host range of crops in the families Solanaceae, Malvaceae, Cruciferae, Fabaceae, and others. Early larval instars feed in clusters, skeletonizing the leaves. Black onion aphid [ Neotoxoptera formosana (Hemiptera: Aphididae)] Forms dense colonies on leaves and reduces value of crop due to feeding (sap sucking) and physical presence of aphids on leaf onions. Onion fly [ Delia antiqua (Diptera: Anthomyiidae)] Serious pest of onion and other related allium crops. Larval feeding on the roots/ base of the plant leads to distorted growth of bulbs and rotting of tissues. Young seed- ling may wilt and die due to larval feeding. Often the bacterium Bacillus carotovorus enters the maggot damaged areas and causes soft rot. Leafminers [ Liriomyza spp. (Diptera: Agromyzidae)] Tunneling of leaves by larvae results in thin white trails/mines on leaves, causing reduced photosynthesis and yield.

Onion fly, Pest and Diseases Image Library, Bugwood.org