Oxidative biotransformations insects

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. 

Recall in our discussion of routes of biotransformation we considered species differences using malathion as an example. Insects convert this compound to its toxic oxidation product more quickly than they detoxify it by hydrolysis. Humans do the conversions in the opposite priority. However, the insects which might be different from the general population and perform detoxification reactions at a faster rate would survive pesticide application and their "resistant" genes would be selectively passed on to the next generations. 

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