Nesting ecology and floral resource of Xylocopa augusti Lepeletier de Saint Fargeau (Hymenoptera, Apidae) in Argentina

Abstract

A total of 33 nests of Xylocopa augusti was studied during two consecutive seasons. Nesting behaviour and floral resources used by the large carpenter bee X. augusti Lepeletier de Saint Fargeau were studied during the brood production season in an urban area in Argentina. Biological information about nesting aspects inside and outside the nest was considered, paying particular attention to year-long activity, foraging flights throughout the day for nectar and pollen collection, nectar dehydration, oviposition, and pollen preference. In the study area, X. augusti shows an univoltine life cycle, with a peak of nesting between October and December, which coincides with the greatest blooming period of the surrounding flora. From 36 analyzed larval provision samples, 18 pollen types were identified, most of them belonging to ornamental trees or shrubs. Pollen from Eucalyptus-Myrceugenia glaucescens (Cambess.) D. Legrand and Kausel (Myrtaceae), Solanum sp.-Cyphomandra betacea (Cav.) Sendtn. (Solanaceae) and Erythrina crista-galli L. (Fabaceae) was dominant. The ability to obtain pollen from poricidal anthers such as those of Solanum indicate the potential of X. augusti to be an excellent managed pollinator and a good candidate for pollinating Solanaceae, such as Solanum lycopersicum ‘tomato’ and Solanum melongena ‘eggplant’, which are economically important crops in this region.