Housefly cyclodiene resistance

At this time I was interested in the natural tolerance of houseflies to structural analogues of dieldrin and, with Harrison, I soon showed that whereas tolerance to cyclodienes was often related to oxidative detoxication and could be reduced or eliminated by benzodioxole synergists, dieldrin-resistance in houseflies did not respond to synergism and was apparently not a consequence of oxidative detoxication (33) Several laboratories (for their subsequent reviews see 34-36) confirmed the importance of oxidative biotransformations in insects and in 1964-5, at Slough, J. W Ray showed that microsomal preparations from houseflies and other insects contained cytochrome P450 (37) Thus, the links between insect and mammalian biochemical pharmacology were finally and firmly established. 

The cyclodiene group of organochlorines was introduced in 1948, starting with chlordane, then aldrin, dieldrin, endrin and toxaphene, and then heptachlor BHC was already available at the close of the war. The experience with housefly control in the Mediterranean countries was that DDT-resistance came in 2 years, and the substitution of BHC was followed by BHC-resistance a year... 

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