Hábitos de nidificação e distribuição da formiga lava-pés Solenopsis saevissima (Smith, 1855) em área urbana

Abstract

Ants of the Solenopsis genus are usually reported on urban environments due to favorable weather conditions and to their ability of exploring resources and competing with other species. On this sense, our study becomes of great importance, since the fire ants are accounted for causing countless economic losses regarding the urban environment, public health and plantation areas. This work aimed to determine the distribution, nesting habits and temperature variation through a day in colonies of Solenopsis saevissima in an urban area in the municipality of Juiz de Fora. In order to study nesting and distribution, samples were taken between October 2013 and August 2015, in which two samplings took place during the rainy season and two during the dry season. For each active colony, we recorded its dimensions and the kind of substrate it was located on. Data on temperature, relative humidity of air and precipitation were given by Laboratório de Climatologia e Análise Ambiental (LabCaa) of UFJF. In order to verify temperature variation through the day, samples were taken once during the rainy season (January 2015) and once during the dry season (July 2015). Measures were taken by using a probe-like digital thermometer and a laser thermometer. Results showed that fire ant colonies remained active in the urban environment for the whole year, and that abiotic factors influenced on their nesting. The nest distribution of S. saevissima was significantly aggregated in both seasons. The most used kind of substrate was the Artificial-Natural. Regarding the mound’s temperature in the rainy and dry seasons, surface values showed greater fluctuation during the day when compared to the mound’s interior. These results are important to build knowledge on the biology and behavior of S. saevissima in urban environments and to generate subsidies for future control strategies and reduction in the number of accidents with human beings.