The potential of the weed Waltheria americana for integrated management of pollinators and pests was evaluated by quantifying bee and wasp richness and amount of visitation to its flowers. Observations were made in two patches of the weed at the Campus of the Universidade Federal de Minas Gerais, Belo Horizonte, MG. Production of flowers, visitor richness and frequency of visits were estimated by inspecting 20 plants in each patch every month. We recorded a total of 37 bee and 72 wasp species. There was a significant correlation between the number of species and number of visits of wasps with the number of flowers for one of the sites. A large proportion of the bee and wasp species recorded at each site were found only one month of the year, or only a single day. Only two species of predatory wasp, Ammophila gracilis Lepeletier, 1845, and Bicyrtes angulata Smith, 1856, visited the weed during all 12 months of the study. Augochloropsis callichroa Cockcrell, 1900, was the most frequent bee, occurring during 9 months. Waltheria americana is a very succesful colonizer of cultivated lands and disturbed habitats, and by virtue of the nectar supply it offers to a large variety of bees and wasps it can be suggested as an aid in integrated pollination and pest management programs.
Insecta; Hymenoptera; biological control
