Phorids associated with nests of Atta cephalotes (Hymenoptera: Formicidae) in a forest and a plantation

Abstract

The external portion of Atta cephalotes nests is composed of three areas: openings, trails, and cutting; where cutting and transporting leaves, sharing information, and defending the nest take place. The richness of the fauna of these areas is not only dependent on the interactions among ants, but also the accumulation of plant material and nest waste, which are exploited by flies of the family Phoridae. Traps with two different kinds of bait were used both during the day and at night to exploit common aspects of phorid fly biology and behavior, such as their attraction to live ants and refuse dumps, their use of visual and olfactory signals, and their perching behavior. Nests in both a citrus monoculture and a forest remnant were studied to evaluate whether environmental characteristics of the sites influence the presence of phorids. One parasitoid, Eibesfeldtphora attae, and 13 additional, mostly saprophagous, genera of phorids associated with A. cephalotes were collected in the nests. Specimens from 12 genera were identified in the forest remnant, most frequently Megaselia, Coniceromyia, and Synclinusa. Nine genera were identified in the citrus plantation, mostfrequently Dohrniphora and Megaselia. Using Analysis of Similarities (Anosim), significant differences (P = 0.002) in faunal composition were found between the forest remnant and the plantation, but no significant effect was detected infaunal composition between areas of the nest (P = 0.206), between baits (P = 0.956), or between periods (P = 0.603).