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Studies on the diversity of social wasps in agricultural environments represent an important step to identifying the ideal species to be used in biological pest control programs. There is a growing effort to acknowledge the diversity of such Hymenoptera in the state of Minas Gerais, but information on anthropized environments is still rare. The objective of this study was to obtain data on the diversity of social wasps in the Instituto Federal de Educação, Ciências e Tecnologia de Minas Gerais (IFMG), Bambuí campus, Minas Gerais, Brazil. Sampling was conducted from July 2012 to July 2014 with two methodologies: attractive traps and active search. This work confirms that a well diversified environment, even if anthropized, is rich in social wasp species. In addition, the great number of collected species, shows the importance of a long-term survey and the use of more than one method of collection. The high rate of collections of Polistes versicolor in a predominantly agricultural environment, coupled with other studies on this species as a predator of lepidopteran caterpillars, suggests the use of this species as a tool in the biological control of pests.

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Kale (Brassica oleraceae var. acephala) is of great importance in human nutrition and local agricultural economies, but its growth is impaired by the attack of several insect pests. Social wasps prey on these pests, but few studies report the importance of this predation or the potential use of wasps as biological control for agricultural pests. This study aimed to survey the species of social wasps that forage in kale (B. oleraceae var. acephala), recording the influence of temperature and time of day on the foraging behavior of these wasps. The research was conducted at the Federal Institute of Education, Science and Technology of Minas Gerais - Bambuí Campus, from July to December 2015, when twelve collections of social wasps that foraged on a common area of kale cultivation were made, noting the temperature and time of collection for each wasp. Polybia ignobilis, Protonectarina sylveirae and Protopolybia sedula were the most common wasp species foraging in fields of kale. Interspecific interactions between wasp species did not affect their coexistence within kale fields, with peak foraging occurring between 1000 and 1100 hours. Social wasps are important predators of herbivorous insects in the agricultural environment and the coexistence of a great diversity of these predators can help control pest insects that occur in the crop. Moreover, knowing factors that influence foraging behaviors of common wasp species that occur in this crop is important for effective use of these insects in the biological control of pests.

Social wasps (Hymenoptera: Vespidae) of the subfamily Polistinae, being biological pest control agents, can effectively participate in ongoing efforts to limit the use of chemical agents used in combating insect pests in urban forestry. The objective of the study, conducted in Viçosa, Minas Gerais State, Brazil, in May 2011, was aimed at identifying species of this group foraging on Eugenia uniflora Linnaeus (Myrtaceae) plants. The study area was monitored once a week, even as data on social wasps foraging on plants of E. uniflora were collected. The data collected included study of their daily activity pattern, diversity, dominance and overlap of temporal niches relating to species of this group. Data analysis revealed that E. uniflora plants were visited by 217 individuals of 16 species of the subfamily Polistinae. Foraging behavior of social wasps bore no relationship with sampling time, but overlap of temporal niche was high. It was observed that the species of social wasps did not damage healthy fruits, but they were probably searching for Lonchaeidae and Tephritidae larvae. It is important to preserve the diversity of these predators, since they are potentially important as a partial alternative to environmentally degrading chemical pesticides currently used in urban forestry for pest control.

Brazil stands out for its coffee plantations for which the 2015 harvest yielded a revenue of over 600 million dollars. Its production is closely related to biotic and abiotic factors, and insect pests are noted for reducing this production. However, those insects are highly influenced by biological control agents such as predator wasps. This study aimed to survey the wasps visiting intercropping coffee cultivation with different tree species. Four plots of coffee intercropped with different tree species and coffee in full sun (control) were sampled for comparison. Tree species were: Teak (Tectona grandis L.f), Australian redcedar (Toona ciliata M. Roem.), Mangium (Acacia mangium Willd.) and Avocado (Persea americana Mill.). Six hundred and thirty-nine individuals of social wasps were collected, with 20 species and 7 genera, and an overall diversity index of 1.14. The plot with Avocado had the highest Shannon diversity index (H ‘) 1.23 and the lowest dominance according to the Index Berger-Paker (DPB) 0.54.

Social wasps have been successfully utilized as means of biological control, particularly for the larvae of Lepidoptera. Ascia monuste orseis causes devastating effects on the kale, inducing production losses of up to 100%, therefore, requiring stringent control measures. This work aimed testing the species Polistes versicolor as potential means of biological control of A. monuste orseis, during autumn and winter, when the kale crop shows good development. These experiments were conducted at the IFMG -Bambuí Campus, between May and June 2017, during which time four P. versicolor colonies were translocated to artificial shelters constructed in proximity to the kale crop, being registered daily the predation of the social wasp on like of A. monuste orseis caterpillars. The translocation of P. versicolor colonies onto the kale crop during the cold and drought seasons was shown to be ineffective in controlling the A. monuste orseis population. This was because this social wasp exhibited low foraging activity, and therefore a low degree of predation on the target pest; however, it became crucial to assess their activity during the hottest and most humid times of the year, as P. versicolor effectively preys upon the various species among the Lepidoptera.

Social wasps play important ecological roles, such as the natural biological control of other arthropods as well as major components of the flower-visiting insect guild. Despite many studies focusing on the survey of these organisms in Brazil, information on the community structure of polistines in anthropized environmets is still rare. The goals of the present study were: i) to survey the social wasp fauna in an anthropized area in the transition of Cerrado and Atlantic Forest; ii) to investigate the efficiency of two sampling methods, namely active search for wasps and the use of attractive traps; iii) to investigate the performance of different attractive baits in the capture success of social wasps in the study area. Sampling of social wasps was conducted by actively searching for individuals and by using attractive traps. A total of 40 species was recorded, with Agelaia multipicta and Agelaia vicina species being the most frequently collected with attractive traps and Mischocyttarus cassununga by actively searching for wasps. In all analyses performed (except when comparing abundance of social wasps considering the molasses bait and the active search), actively searching for wasps was the best method. This is also highlighted by the fact that the time spent actively capturing polistines was considerably lower than the time (and costs) that the traps were left in the field. Active search, as demonstrated by previous studies, remains as the best capturing methodology when surveying Neotropical social wasps, either in natural or anthropized environments.