Studies on Wheat Bulb Fly, Leptohylemyia Coarctata, Fall

Abstract

Data were principally taken in a wheat field at South Duffield, England. Eggs are laid in the soil and the larvae attack the shoots of the developing plants. Estimates of the number of plants and larvae per acre and the % of damage were obtained by sampling. The total number of plants per acre was estimated at about 11/2 million which remained fairly uniform from Jan. to Apr. The plants had from 1 to 2 shoots each in Jan. and increased to an average of over 3 1/2 in Apr. On Jan. 26th there were estimated to be 1600 larvae and 1600 damaged shoots per acre and 0.1% damage. The infestation increased to a peak the latter part of Mar. and early Apr. at which time there were estimated to be 583,000 larvae or puparia per acre and about 45% of the plants showing damage but only about 18% of the shoots were damaged. The crop, after all, was a success, the reasons offered being a high initial number of plants and that early sowing resulted in early division into shoots.