Impact of the Imported Fire Ant on Laboratory Populations of Cotton Aphid (Aphis Gossypii) Predators

Abstract

The presence of a few red imported fire ants, Solenopsis invicta Buren, workers on aphid bearing cotton plants reduced aphid predator effectiveness in the laboratory. The predators Hippodamia convergens Guerin-Meneville adults and 3rd instar larvae were effective in reducing Aphis gossypii Glover populations as did 3rd instar larval Chrysopa carnea Stephens, Scymnus louisianae Chapin and Syrphus sp. larvae. However, all of these predators were ineffective in the presence of fire ants which were capable of killing all species although both Scymnus and Syrphus larvae sometimes escaped. Although predators may be killed they may prefer areas of low ant encounters in the field thus surviving and reducing their impact on fire ant tended aphid populations.