High populations of thrips are promoted by a mild winter and a sunny spring.
- Thrips are tiny brown or black insects (approximately 1 mm in length) and are most often found between the petals of the flowers.
- Their mouthparts pierce plant surfaces causing browning of petals and distortion of flowers.
- Leaves are distorted and generally curl upward. The leaves become crinkled and the laminae may be greatly reduced by high populations causing new leaves to be narrow.
The discolouring on the edges of the petals in the picture is caused by thrips.
This picture shows distorted leaves caused by thrip damage.
Survival of hibernating thrips is promoted by a mild winter, a sunny spring and abundant weeds. Female thrips lay colourless eggs in floral tissues. Adults feed on flower parts, later entering the soil to pupate. Thrip life cycles can range from 10 days to a month depending on temperature.
Spray with a registered chemical and remove weeds.