Published online by Cambridge University Press: 31 May 2012
The maggot complex of Hylemya a cilicrura (Rond.) and H. liturata (Meig.) attacked flue-cured tobacco transplants in southwestern Ontario in increasing numbers from 1958 to 1960. Previously they had been of very minor importance to tobacco in this area.
Resistance was suspected near Delhi, in Norfolk County, when abnormal infestations developed in soil treated with aldrin or heptachlor. Planting-water treatments of aldrin, dieldrin, heptachlor, or lindane also failed to give appreciable control. Similar increases in house-fly populations, coincidental with decreased susceptibility to chlorinated hydrocarbon insecticides, have been noted (2).