Populations of trap-nesting wasps near a major source of fluoride emissions in western Tennessee

Trap-nesting wasps were collected from eight sites at distances of from 1.2-33.0 km from an aluminum reduction plant in western Tennessee. The sites had similar topographies, soils, and vegetation, but differed in their exposure to fluoride, which was emitted in large quantities from the plant. It was postulated that if fluoride emissions had greatly changed the insect community then relative densities of their predators would have varied accordingly. However, the degree of fluoride pollution was unrelated to the relative densities of the wasps and to the number of cells provisioned with prey. Monobia quadridens, Trypargilum clavatum, and T. lactitarse were found to have two complete generations in western Tennessee. Trypargilum collinum rubrocinctum has at least two generations, and Euodynerus megaera probably has three generations. Six other wasp species and a megachilid bee were also collected.