Western Flower Thrips

Question 1

Symptoms of Western Flower Thrips (thunder flies)

Answer 1

Extensive range of hosts inc lettuce, potatoes, pome and stone fruit.
Transmit Impatiens Necrotic Spot Virus & Tomato Spotted Wilt Virus.

Direct damage - foliage discoloration/ slivering. Deformed buds. Halo spotted foliage

Question 2

Western Flower Thrips - transmission of tomato spotted wilt virus

Answer 2

WFT - vector if TSWV, larval stage of WFT pick up virus when feeding on affected plants.
Adult stage then passes virus on to other plants; infection can occur in less than 5 minutes of feeding.

Question 3

Symptoms of Tomato Spotted Wilt Virus - transmitted by Western Flower Thrips

Answer 3

Many different plants can be affected.
Symptoms vary greatly depending on species of plant affected and virus strain.
Leaf spots, ring patterns, yellowing and dead tissue, distorted and stunted growth.
Reduction in plant vigour.
Death is possible.

Question 4

Western Flower Thrip - life cycle

Answer 4

Complete life cycle
Females deposit eggs within plant tissue after making small incisions.
Eggs hatch approx 4 days later depending on temp.
Two larval instars, followed by a soil-dwelling pre-pupa and pupa.
Winged adult then emerges.
Whole life cycle takes approx 14 days at appropriate temperatures.
Several generations over a year, year round under protection or all stages may overwinter.
No true period of diapause.