Use of Insecticide to Control Destructive Activity of Ants during Trapping of Small Mammals

Abstract

Feeding by ants (Hymenoptera: Formicidae), particularly fire ants ( Solenopsis invicta ), can negatively affect trapping of small mammals. To reduce loss of bait and mutilation of captured specimens by ants during a study of small mammals in eastern North Carolina, we treated one-half of our trap sites with a chemical insecticide. We evaluated the effects of use of insecticide on trapping of small mammals in three pine-plantation and two pocosin habitats that differed in levels of activity and abundance of fire ants. Use of insecticide did not affect overall capture yield or probabilities of capture for any of the 12 species of small mammals we caught. Rates of mutilation of specimens were lower where insecticides were used, but were significantly reduced only in habitats where abundance of fire ants was high. Use of insecticide reduced destructive and total activity of ants, although effectiveness varied with abundance of fire ants. Destructive and total activity levels of ants were highest where fire ants were abundant, but effects of insecticide on activity were proportionally greater in habitats where fire ants were less abundant or absent.