One thrips, two thrips, fed thrips, dead thrips

From UCNFA News -- By Richard Evans:

Western flower thrips (Frankliniella occidentalis), a widespread pest of many ornamental crops, is hard to control because both juveniles and adults live within flowers and buds, rarely loitering in the open where they would be vulnerable to chemical sprays. Not that insecticides are all that effective anyway. This insect has become resistant to almost everything except Lunchables, and nobody has come up with a suitable spreader-sticker for applying Lunchables to ornamental crops.

Speaking of Lunchables, one pest management approach worth considering is to feed plants in a way that makes them less appetizing to pests. For instance, several years ago researchers at Texas A&M (Chau and Heinz, 2006) examined the effect of liquid feed concentration on western flower thrips abundance on potted chrysanthemums. Plants received a 15-16-17 fertilizer at rates ranging from 75 to 750 ppm nitrogen. The number of thrips was highest on plants fertilized with 280 to 375 ppm N. Mums fertilized at a rate of 188 ppm N had about half the number of thrips found on mums fertilized at 375 ppm N, yet were the same height and produced a similar number of flowers. Unfortunately the authors didn’t report plant dry weight or leaf elemental composition, both good measures of fertilizer effects on growth.

Read the rest of the report here.