Western flower thrips and flower thrips

Frankliniella occidentalis (Pergande) Frankliniella tritici (Fitch)

Thysanoptera: Thripidae

Distribution: QC, NY and PA, and south through the mid-Atlantic states.

Photos

Feeding near harvest results in silvering or russetting of the fruit surface. Mid-Atlantic Orchard Monitoring Guide
C

Western flower thrips [Frankliniella occidentalis (Pergande)] and Flower thrips [Frankliniella tritici (Fitch)] are indistinguishable without a microscope. Adults are slender and yellowish, with short antennae; the wings are long and narrow, and held over the abdomen (A). Larvae are smaller and wingless, but otherwise resemble adults.

Crops Affected: cherries, peaches, plums

Damage

Both species attack nectarine and other stone fruits. Adults infest developing fruit during bloom and again as the fruit ripens. Larval and adult feeding at bloom through shuck fall causes scars on the fruit surface that expand as the fruit grows (B). Feeding near harvest can result in a silvering or russetting of the fruit surface (C). High thrips infestations feeding on terminal growth can cause distortion of leaves and excess branching.

Management

Injury tends to be more severe in orchards located in proximity to greenhouses, and under drought conditions. Insecticide sprays may be necessary at petal fall and close to harvest.