Effects of various photoperiods on the life cycle and susceptibility of the house fly, Musca domestica Linnaeus, to insecticide residues

Abstract

The effects of various photoperiods on the life cycle and susceptibility of the house fly, Musca domestica L., to insecticide residues were studied in the laboratory. Six cultures of flies were established under light-dark (LD) regimens of 10:14, 12:12, 13:11, 14:10, 15:9, and 16:8 in lightproof plywood cabinets. A seventh culture was established under continuous light. All cultures were maintained under controlled conditions at 80??2??F and 50-80 percent relative humidity. Flies reared under LD 14:10 were consistently susceptible to film residues of DDT, endrin, and dieldrin. Flies reared under LD 16:8 and 13:11 were not significantly different in susceptibility from those produced under LD 14:10. Flies reared under LD 13:11 and 14:10 were significantly more susceptible to residues of endrin than all other flies. Flies produced under an LD 15:9 photofraction were the least susceptible to DDT and dieldrin. In studies to compare the susceptibility of one- to two- day old and four- to five-day old flies produced under the seven photoperiods, one- to two-day old flies were consistently more susceptible than four- to five-day old flies to residues of trichlorfon. Four- to five-day old flies reared under certain photoperiods were more susceptible than one- to two-day old flies under certain other photoperiods. ...