As pollination is a critical process in both human-managed and natural terrestrial ecosystems, pollinators provide essential services to both nature and humans. Pollination is mainly due to the action of different insects, such as the bumblebee and the honeybee. These important ecological and economic roles have led to widespread concern over the recent decline in pollinator populations that has been detected in many regions of the world. While this decline has been attributed in some cases to changes in the use of agricultural land, the effects of parasites could play a significant role in the reduction of these populations. For the first time, we describe here the presence of Nosema ceranae, an emerging honeybee pathogen, in three species of Argentine native bumblebees. A total of 455 bumblebees belonging to six species of genus Bombus were examined. PCR results showed that three of the species are positive to N. ceranae (Bombus atratus, Bombus morio and Bombus bellicosus). We discuss the appearance of this pathogen in the context of the population decline of this pollinators.

No abstract

A new case of gynandromorphism in bees is described and illustrated for the first time for Xylocopa (Neoxylocopa) frontalis (Olivier), a widely distributed carpenter bee in the neotropical region. The mixed gynandromorph, recorded from a single specimen from Paraguay, exhibits a mixture of male and female features in all tagmata. Previous literature records of gynandromorphs in Xylocopa Latreille are summarized, and the species identity of some gynandromorphs recorded for South America is revised. Including the specimen described herein, gynandromorphs are now known for a total of 12 species in Xylocopa, half of them in the neotropical subgenus Neoxylocopa.

A systematic revision of the species of the genus Xylocopa subgenus Neoxylocopa in Argentina is provided. Seven species are included: X. atamisquensis Lucia & Abrahamovich, X. augusti Lepeletier, X. eximia Pérez, X. frontalis (Olivier), X. mendozana Enderlein, X. nigrocincta Smith and X. tacanensis Moure. The males of X. eximia and X. nigrocincta are described for the first time. Xylocopa jujuyensis Brèthes is a new junior synonym of X. nigrocincta. Photographs, occurrence maps, and identification keys for the species are presented. Information on the nest architecture and substratum preference are also given.