Thrips

Thysanoptera

Description

Adult thrips are tiny insects about 1/15 inch long that have two pairs of narrow wings with fine hairs on the front and hind edges. These featherlike wings help them to drift long distances in the wind. Immature thrips are slender and elongated and lack wings. Thrips vary in colour from translucent white to dark brown or black.

Life Cycle

Thrips will go through several stages to complete a life cycle. Female thrips insert eggs into plant tissue. Egg hatches and the first instar nymph appears and feeds on plant sap. After one to two days, it begins molting and the second instar nymph emerges and continues feeding. Nymphs are wingless so travel by foot from one feeding site to another on the same plant. Greenhouse thrips transform to prepupae and pupae on the lower surface of the leaves, but some other thrips species drop to the soil or leaf litter to pupate. Prepupae and pupae are nonfeeding stages, and wings appear compared to the nymph stages. The adult thrips will emerge within about five days. Development from egg to adult takes approximately 16 days. The life span of a female is about 35 days, and each female can produce 50 to 300 eggs depending on the species and host plant. Thrips have upto eight generations per year.