Viral infection alters foraging behaviors in invasive ants

Earlier studies have demonstrated that foraging behaviors of the invasive fire ant, including foraging intensity and macronutrient preference, are significantly altered by viral infection. In this study, we investigated the virus-induced behavioral changes in the invasive longlegged ant, Anoplolepis gracilipes. We demonstrated that virus-infected colonies of A. gracilipes foraged significantly less than their uninfected conspecifics in the laboratory conditions. However, the proportion of foragers on carbohydrate foods (i.e., the number of foragers on carbohydrate foods/total number of foragers) was higher in virus-infected colonies than those of the uninfected ones. Field test on seasonal food preference of A. gracilipes with different virus prevalence levels in Penang, Malaysia, during the dry and wet seasons revealed that although season and viral infection affect the ant’s food preference, infected ants significantly increased the intake of carbohydrate foods, irrespective of the season. We will discuss how viral infection interacts with the foraging biology of ants and its pest management implications.