Studies on the environmental persistence of S-31183 (pyriproxyfen): adsorption onto organic matter and potential for leaching through soil.

Analytical methods were developed to allow the extraction and analysis of S-31183 (pyriproxyfen), 2-[1-methyl-2-(4-phenoxyphenoxy)ethoxy]pyridine, in organic matter from animal waste-water lagoons. Analysis of water and organic debris from a treated lagoon showed that the active ingredient readily adsorbed onto organic matter. S-31183 persisted on organic matter for over a 2-month period, during which time the concentration decayed at an exponential rate.

ETOC and lambdacyhalothrin: new pyrethroid mosquito adulticides.

Two new pyrethroids, ETOC and lambdacyhalothrin, showed considerable promise against organophosphorus-resistant adults of Culex tarsalis in laboratory tests. In field trials using nonthermal aerosols, applications of both compounds resulted in effective swaths of up to one-half mile. At the highest concentrations evaluated, residues on alfalfa foliage were less than 0.

Recycling suitability of wash waters from mosquito abatement vehicles and equipment into spray diluent.

In response to changing laws as well as increased concern over environmental pollution, there is a current need to examine the best means of disposal of wash water generated by mosquito abatement operations. A study of wash waters from 6 central California mosquito abatement districts shows that herbicide levels were low enough so as not to preclude the use of these waters for recycling back into insecticide spray diluent. In one case, oil levels were high and an oil/water separation is probably necessary to prevent gum formation and clogging of spray equipment.