CONTROL OF THE TURNIP MAGGOT, HYLEMYA FLORALIS (FALL.) (DIPTERA: ANTHOMYIIDAE), IN RUTABAGAS

Abstract

Three spray treatments of heptachlor at 4 pounds, dieldrin at 4 pounds, or endrin at 2 pounds in 80 gallons of water per acre in a 12-inch band centered on the rutabaga row eliminated maggots of Hylemya floralis (Fall.) about the roots and prevented damage by the maggots, when applied at intervals of 10 or 11 days beginning within 2 or 3 days after the start of oviposition. Residues of dieldrin were below and those of endrin were above the legal tolerances in Canada. Residues of heptachlor (epoxide not determined) were below the legal tolerance. A single soil band treatment of heptachlor, dieldrin or aldrin dust at 5 pounds per acre, applied in a 12-inch band on the seeded rows and incorporated immediately into the top [Formula: see text] to 1 inch of soil, gave similar control, but insecticide residues in the rutabaga were not determined. None of the treatments was phytotoxic.

An Assay for Determining Insecticide Tolerance of Onion Maggot Larvae

“…An 80-fold difference in tolerance between maggots from tolerant and susceptihie srrains was not reflected as a measurable difference among the ndults of these strains. This species has been subjected to heavy applicntions of heptachIor (Stewart 1962) for 10 years and may still be controlled with this insecticide. Possibly the processes leading to increased tolerance may have been delayed by the application of heavy dosages to a species that differs greatly in biology and ecology from related root-infesting species.…”