Cotton Thrip ppt its morphology and biology

Its is a cotton thrip pdf to focus on highlights and main points and its biology

1. Thrips ( Thrips tabaci ) It is a cosmopolitan and polyphagous species distributed all over the country. Marks of identification : The adults are minute delicate insects about 1 mm in length and are light yellow in colour . Their body is narrowed in the middle. Their wings are fringed with hairs, hence called as fringe winged insects. The nymphs and even adults are seen walking fast, when observed under magnifying lens Host range : Cotton, chilly, cucurbits etc.

2. Biology The eggs are laid in the tissues on the lower surface of leaves. A female lay about 30-50 eggs. These eggs hatch in about 2 to 5 days. Nymphs become full grown in about a week, after moulting thrice. The adult lives for 10 to 25 days. There are 3-4 generations in a year.

3. Nature of damage The thrips have rasping and sucking type of mouth parts suited for scraping the epidermal tissues of the leaves and sucking the oozing cell sap. As a result of such feeding brown patches are seen of the leaves and also on bolls. Excessive feeding on leaves leads to curling and the growth on the plant is stunted. The pest is active in post monsoon periods.