The natural mortality of wheat-bulb fly eggs in bare fallow soils.
The survival of four populations of eggs of Hylemya (Leptohylemyia) coarctata (Fall.) at Rothamsted in southern England was studied. Few eggs disappeared between the time of laying in July and August and hatching in February. Of 3000 eggs from soil samples, none was parasitised, 1% were diseased and 2-14% were sterile. Carabids were the most abundant predators present, but excluding them from plots did not affect egg mortality. Only 21% of the Carabids were present in the open field where the eggs of H. coarctata are laid, the remainder occurring around the edges of the field three species of Carabids forming 42% of the total catch destroyed eggs, four species comprising 44% did not.