How do frequent fires in the Cerrado alter the lepidopteran community?

Abstract

Despite the great biodiversity of lepidopterans, there are few studies focusing on caterpillars and the effects of fire on their community structure in the Cerrado. The aim of this study was to evaluate the effects of frequent fires every 2 years for 16 years, on the Lepidoptera larval community hosted on Byrsonima coccolobifolia (Malpighiaceae). The study was carried out in the Cerrado sensu stricto in the Reserva Ecologica of the Instituto Brasileiro de Geografia e Estatistica (IBGE-RECOR) (15°55′–15°58′S, 47°52′–47°55′W), in Distrito Federal, Brazil, from December 2005 to August 2006. We selected two burned parcels, one of which was burned during the mid-dry season (FM) and the other of which burned in the late dry season (FL), in addition to a preserved, unburned parcel (FA). In each parcel, 900 plants of B. coccolobifolia were inspected for caterpillars, which were then collected and reared in a laboratory of the University of Brasilia. We found 480 caterpillars from 49 species distributed in 16 Lepidoptera families. The frequency of plants with larvae, the number of caterpillars and species composition varied among parcels. In the unburned parcel the frequency of plants with caterpillars was 2.4 and 5.2 times higher than in burned parcels (FM and FL), respectively. The species richness did not differ among parcels, and an asymptotic curve was nearly reached in only the unburned parcel. The dominant species in the preserved parcel was Cerconota achatina (Elachistidae). In the FM, the dominant species was Concana mundissima (Noctuidae) and in the FL, the dominant species was Stenoma salome (Elachistidae). The dissimilarity between unburned and burned parcels was 64%. Results indicated that fire events have a strong negative impact on caterpillar abundance and species composition.