Levantamento de vespas sociais (Hymenopytera, Vespidae) em eucaliptocultura

Abstract

The social wasps are predators of many insect species, mainly caterpillars, which shows their potential for programs of biological pest control. The first stage of the these programs is to identify species found in a particular system. Twelve monthly samples were made at eucalyptus plantation in Coronel Pacheco, Minas Gerais States Brazil, with two methods: active search on trails and the plantation (wasps collected with entomological net) and attractive traps (made with two-liter "pet" bottles, with a lateral opening) tied to eucalyptus trunk at approximately 1.5m high above the ground. One hundred and fifty ml attraction substrate was put: passion fruit juice or guava juice (fruit, water and sugar) or broth of sardines (sardines preserved and water). Thirty six bottles was used for collection (12 bottles for each substrate) in four transects of 80m (T1 and T2 - forest-eucalyptus; T3 and T4 - eucalyptus plantation), each with nine traps, distant one from another 10m. Climates data (temperature and precipitation) was obtained from the meteorological station of EMBRAPA Cattle and Milk in Coronel Pacheco. Twelve species of social wasps of six genera were identified. The active search sample method collected 10 species and six in the traps. The active search obtaining the greatest diversity (H' = 0.83), followed by attractive traps with passion fruit juice (H' = 0.38), guava juice (H'= 0.29) and sardines (H' = 0.18). The active search (83.3%) brad higher efficiency. was The greatest number of species occurred in transects of edge (T1 and T2), next to the native forest. There was no correlation between the social wasps species xviii and climatic variables (temperature and precipitation), but swarm-founding species have been recorded during every month of collection and independent foundation were not obtained in January and June. Those with, the best methodology is the combination of two or more techniques, since a specific methodology did not all species collected. It is important to maintain fragments of native vegetation nearly eucalyptus plantations, as a strategy to increase natural occurrence of species social wasp. All seasons are favorable to manage social wasp in eucalyptus plantation, especially for swarm-founding species.