Carbohydrate-based mosquito control: A field test of the concept

Abstract

We tested the concept of using a carbohydrate-based mosquito control method on saltmarsh mosquitoes. In laboratory trials, xanthan gum, a type of carbohydrate gum thickener, killed both fourth-instar and pupae of Aedes sollicitans (Walker). The lethal time 50 was shorter for the pupae than the fourth instars, 35.8 and 61.2 min, respectively. In a screen of commercially available carbohydrate gum thickeners and starches we did not find any compounds that had properties, other than xanthan gum, useful for testing the concept of carbohydrate-based mosquito control. Therefore, in the field study, we tested xanthan gum at the maximum rates used previously, 22 g/m2. This allowed us to test the concept of using such a control strategy in field conditions. Under these conditions, xanthan gum increased the Ae. sollicitans mortality rate to 67% (±3.9% SE), a level not significantly different from the Abate treatment, 73% mortality (±7.7% SE). We also examined the effect of xanthan gum and a commercially available starch, National 5370, on the biological oxygen demand (BOD) in the marsh environment. This allowed us to determine at what rate a practically applicable carbohydrate would have to be delivered to the marsh environment such that the BOD is not affected. Our initial findings suggest a practically applicable carbohydrate-based mosquito control agent would have to be delivered at or below 2.2 g/m2.