The seasonal deciduous forest, also known as dry forest, is characterized by the deciduity of tree species and two well-defined seasons which cause drastic changes in its physiognomy, and the seasonality of rainy periods directly impacts the forest’s biological communities. Social wasps (Vespidae: Polistinae) are well documented. However, some ecosystems in which they occur, such as the deciduous forest, are still subsampled. This study aimed to assess the response of social wasp communities to the dry season in a deciduous forest in the Mata Seca State Park, in the North of the state of Minas Gerais, Brazil. Insects were collected over 24 days divided into four field campaigns, each with six continuous days of collection (February, May, July, and November 2021), encompassing one campaign per season. All specimens were sacrificed and stored in 70% alcohol and later dry mounted for identification. The Kruskal-Wallis (KW) H test was performed to verify the difference between species richness, number of total colonies, and number of colonies of each tribe in relation to the collection station. In total, 131 colonies of eight species were located, particularly Polybia occidentalis (Olivier, 179), with 39 colonies, Polistes versicolor (Olivier, 1791), with 33, Mischocyttarus cassununga, with 21, and Protonectarina sylveirae (Saussure, 1854), with 13. Six species, five of which were from the Epiponini tribe, were collected in the four seasons. The responses of social wasps to the periods of drought in the deciduous forest vary with tribe. While Epiponini populations can keep colonies active in the dry season, Polistini cannot. Meanwhile, P. versicolor responds positively to the onset of the rainy season, increasing its population.

Eumeninae is the subfamily with the highest number of species among Vespidae family, with more than 3,750 species and 210 genera identified worldwide. Some ecosystems are subsampled, such as the decidual seasonal forest, also known as dry forest. Thus, this study aims to execute the inventory of the Eumeninae community in decidual seasonal forest in the Parque Estadual da Mata Seca, Minas Gerais. The study took place from February to December 2021, executing active search and using malaise traps. A total of 90 individuals, belonging to 30 species, was collected, which characterize this study as the fourth highest list of Eumeninae for Brazil, even with a smaller sampling effort than other similar studies. In this study, 40% of the collected species are rare, having been collected only once. The most abundant species were Pachodynerus brevithorax (Saussure, 1853), Hypalastoroides brasiliensis (Saussure, 1856), Pachymenes ater (Saussure, 1852) and Montezumia petiolata (Saussure, 1855). This research shows how the Neotropical Eumeninae fauna is still little explored, indicating the need for more research to be conducted with this taxon, especially in environments without exploration such as the decidual seasonal forest.

The survey and identification of social wasps, mainly in predominantly agricultural environments, is the first step to identify the ideal species to be used in biological pest control programs. The present work aims to inventory the social wasp fauna in an agrosystem in the Cerrado, Minas Gerais and identify species with potential to be used in biological control. Through active search, 478 wasps of 8 genera and 17 species were collected. The dominance of some species such as Protopolybia sedula, Polybia ignobilis, Polybia paulista, Polybia fastidiosuscula and Polybia occidentalis reinforces the importance of these species in agricultural environments and their potential use in biological pest control. In addition, this work confirms that some species of social wasps benefit from the anthropized environment, such as Polistes versicolor, which uses human constructions for nesting.