Citrus thrips add blueberries to their diet

With the advent of heat-tolerant blueberries, growers have established a California blueberry industry. But, along with the new opportunities offered by this crop, comes a new struggle—citrus thrips.

Citrus thrips have expanded their host range to become a major pest of blueberries. Help is on the way, though, from a team of researchers funded by the University of California Statewide Integrated Pest Management Program (UC IPM).

Adult citrus thrips are small, orange-yellow insects with fringed wings. During spring and summer, females lay about 25 eggs in new leaf tissue.


Both adults and immature thrips feed on and damage newly developing leaves and stems.

In fall, overwintering eggs are laid mostly in the last growth flush of the season. Citrus thrips also are prolific and can produce up to eight generations during the year if the weather is favorable.

UC IPM Farm Advisor David Haviland is looking at nonchemical ways to keep the thrips from spreading. Haviland, UC Riverside entomologist and citrus thrips expert Joseph Morse, and blueberry expert and Farm Advisor Manual Jimenez have found what time of year citrus thrips are present in blueberries, where to look for thrips on the crop, how to monitor for thrips, and some of the damage they cause.

During the first year of this three-year project, Haviland and his team held field trials in three commercial blueberry fields in Tulare and Kern counties. They identified May through early October as the period when citrus thrips are present in blueberry canopies, and learned that thrips densities peak in July and August.

Contact:
Stephanie Klunk
STATEWIDE INTEGRATED PEST MANAGEMENT PROGRAM
UNIVERSITY OF CALIFORNIA, DAVIS
ONE SHIELDS AVENUE
DAVIS, CA 95616-8621
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