Carrot Rust Fly

(Psila rosae), an insect of the family Psilidae; a dangerous pest of umbellifers. Body length, 4–5 mm. The head is brownish red, the legs and antennae are dirty yellow, and the thorax and abdomen are shiny black with a greenish iridescence. The carrot rust fly is found in Europe and North America; it is distributed almost throughout the European USSR. In regions with high humidity, the insect severely damages carrots, parsnips, parsley, celery, dill, and other plants.

The carrot rust fly develops in two generations. The eggs are deposited one at a time under clumps of soil or in cracks in the soil at the bases of damaged plants; less frequently the eggs are deposited on carrot plants when the plants are forming two or three true leaflets. The hatched larvae bore their way mainly into the tips of roots or into root crops. Young plants often die. The damaged roots of root crops become bitter and, covered with transverse rust-colored cracks and wormholes, often rot. Measures used to control the carrot rust fly include deep autumn plowing, preplanting dusting of seeds with insecticides, late-fall or early sowing of carrots, timely weeding and thinning, and applying naphthalene two or three times during the egg-laying period.