Effect of xanthan gum and traditional mosquito larvicides on chironomid larvae

Chironomid larvae are an important food source for many species of wildlife that depend upon wetland habitats. Using various pesticides to control mos quitoes may impact chironomid larvae, with important consequences to the qu ality of these wetland habitats for wildlife. We tested the effect of tradi tional mosquito larvicides: Bacillus thuringiensis var. israelensis (BTI), temephos, a carbohydrate gum thickener (xanthan gum), and a modified starch (National 5370) on chironomid larvae in a wetland located in eastern Delaw are. Only temephos reduced numbers of live chironomid larvae observed (P<0. 01). We discuss the potential role of a carbohydrate-based mosquito control method in wetlands where chironomid larvae are the nontarget invertebrates of concern.