Fire ant predation on native and introduced subterranean termites in the laboratory: effect of high soldier number in Coptotermes formosanus

Abstract. Native Reticulitermes spp. Holmgren and the introduced Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) were exposed to predation in the laboratory by Solenopsis invicta Buren (Hymenoptera: Formicidae), a known predator of Reticulitermes. In one experiment, both taxa contained the 2.4% soldiers commonly found in Reticulitermes. In a second experiment, Reticulitermes contained 2.4% and C.formosanus a more normal 18.3% soldiers. When soldier proportions were equal, C.formosanus soldiers suffered less of a decrease in survivorship due to predation compared with Reticulitermes soldiers. Little difference was found between taxa in the effect of predation on termite workers or in the effect of termites on predator survivorship. When soldier proportions were unequal, both C.formosanus castes suffered less from predation than those of Reticulitermes. Again, little difference was found in the effect of termites on ants. C.formosanus showed less movement into new containers when soldier number was abnormally low, compared with both taxa with normal caste proportions.