Cross-resistance cyclodienes

Yu and Nguyen (1996) showed that selection of a strain of diamondback moth (Plu-tella xylostella) with permethrin for 21 generations resulted in over 600-fold resistance to permethrin in this strain. The resistant strain was also cross-resistant to all pyrethroids tested, including bifenthrin, fenvalerate, esfenvalerate, A.-cyhalothrin, fluvalinate, and tral-omethrin. However, it remained susceptible to organophosphate, carbamate, cyclodiene, neonicotinoid, avermectin, and microbial insecticides tested. Biochemical studies indicated that pyrethroid resistance observed in this strain was most likely due to decreased target site sensitivity. 

One important group of insecticides, the avermectins, works differently by being agonists and not antagonists as the other, acting on the chloride channels. The avermectins are produced by Streptomyces avermitilies. The binding site is different, and cross-resistance to fipronil, the cyclodienes, and lindane does not seem to occur. The toxic symptoms in insects and mammals are different. Mammals poisoned with avermectins exhibit hyperexcitability, incoordination, and tremor followed by ataxia and paralysis. In insects and nematodes, the hyperexcitation phase is absent. Their symptoms are... 

There is considerable, but variable, cross resistance from DDT to other chlorinated hydrocarbons such as benzene hexachloride and the cyclodiene insecticides. However, when one substitutes a para-methoxy group for para-chlorine in the DDT molecule, a far less persistent—and somewhat less active—but... 

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