Preferences for anuran calls in hematophagous corethrellids (Diptera: Corethrellidae) from Southern Brazil

Abstract

AbstractCorethrellids are hematophagous flies that locate their frog hosts by using their calls as an auditory cue. The attractiveness of frog calls to these insects has been associated with the complexity of the vocalisation or an evolutionary relationship between the fly and frog species. We investigated the possible preferences of a local Corethrella fauna for the calls of six anurans, three species of the genus Boana (Hylidae) and three Physalaemus (Leptodactylidae) species in the Atlantic Rainforest of southern Brazil. We recorded loops of the natural advertisement calls of the different frog host species, which we broadcast from acoustic traps consisting of modified CDC (Center for Disease Control) traps fitted with a speaker under the collecting system, but without a source of light. Nine species of hematophagous flies were captured during 360 h of trapping. Three of the species captured were new to Brazil, and two could not be identified and may represent new taxa. Two corethrellid species contributed 75% of the individuals captured and were present in all the acoustic traps, while three species were attracted to only one trap. The median richness and abundance of corethrellids varied significantly in relation to the different calls broadcast by the traps. These differences in the abundance and species richness of Corethrella in the traps indicate that the frog calls vary in their attractiveness to the hematophagous flies. A model‐based analysis using mvabund also indicated that the frog species and genera that produced the calls used in an acoustic trap were a significant factor determining the composition of the Corethrella assemblages captured in that trap. The variation found in the Corethrella communities of southern Brazil may be explained not only by the acoustic traits of frog vocalisations but also by differences in the morphological and ecological characteristics of the frog species.