Dieldrin resistance mechanisms

We now know that a single gene on chromosome IV is responsible for dieldrin resistance in houseflies. The mechanism is still obscure, although recent work has shown that houseflies do metabolise small amounts of dieldrin (28). 

Resistance to DDT has been developed in many insect species. Although there are some cases of metabolic resistance (e.g., strains high in DDT dehydrochlorinase activity), particular interest has been focused on kdr and super kdr mechanisms based upon aberrant forms of the sodium channel—the principal target for DDT. There are many examples of insects developing resistance to dieldrin. The best-known mechanism is the production of mutant forms of the target site (GABA receptor), which are insensitive to the insecticide. 

The mechanism of cyclodiene-resistance has been very difficult to determine. The hydroxylation of aldrin and dieldrin to aldrin glycol and dieldrin transdiol is a slow process and is not peculiar to resistant strains, while the increased lipoid content... 

Aldrin binds strongly to soil particles and is very resistant to leaching into groundwater. Volatilization is an important mechanism of loss from the soil. Due to its persistent nature and hydrophobicity, aldrin is known to bioconcentrate, mainly as its conversion products. As aldrin is readily and rapidly converted to dieldrin in the environment, its fate is closely linked to that of dieldrin. Aldrin is readily metabolized to dieldrin in both animals and plants, and therefore aldrin residues are rarely present in animals and then only in very small amounts. Residues of aldrin have been detected in fish in Egypt the average concentration was 8.8pgkg , and a maximum concentration of 54.27 pg kg Aldrin has... 

While dieldrin target-site resistance (Section 29.5.2.2) can confer some level of resistance to fipronil, this cross-resistance has not led to failure of fipronil in the field. However, resistance due to other mechanisms was seen in southeast Asia as early as 1996 in diamondback moth Plutella xylostella), within three years of the introduction of the product. The high intrinsic activity of fipronil and lack of alternatives in the mid-1990s led growers in countries such as Thailand to use it up to 40 times per year on cruciferous crops. By early 1997, many populations were resistant and field failures were widespread. At the same time, use of the... 

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