Diversity of Social Hymenoptera (Hymenoptera: Aculeata) and Reduction of Sampling Effort in a Dense "terra-firme" Rainforest in the Amazon

We investigated the richness and composition of social Hymenoptera collected with a Malaise trap in a rainforest in the Amazon. In addition, we studied the possibility of reducing the number of traps and the time the traps remain in the field to minimize the sampling effort. In reducing sampling effort, we seek to maintain taxonomic standards (similarity in composition) and reduce both the time the Malaise trap remains in the field and the number of traps per plot. We collected 63 species of social Hymenoptera, represented by 11 species of Apidae, 31 of Formicidae, and 21 of Vespidae, in 30 plots of 250 m distributed in 25 km2 of rainforest in the Amazon. It was possible to reduce the permanence time of the Malaise trap in the field from 72 to 48 hours without significant loss of the maximum recorded diversity since there is high similarity (80%) to the maximum effort of 72 hours of sampling. The reduction from two to one trap directly impacted the sampled diversity. We estimate savings of 30.53% by reducing sampling effort and trap dwell time, allowing the resources saved to be invested more efficiently in biodiversity monitoring studies in the Amazon basin.