Evidence of Nest Reactivation and Perennial Colonies in the Neotropical Bumble Bee Bombus brevivillus (Hymenoptera: Apidae: Bombini).

Bombus brevivillus Franklin is a Neotropical Bombus species whose colonies are disappearing from most of its native range, and little is known about its biology and reproductive habits to help conservation or breeding efforts. Unlike Bombus species from temperate climates whose colonies perish every winter, there are suggestions of perennial colonies that Neotropical Bombus species can present. In this work, we investigated the development of two B. brevivillus colonies (i.e., number of workers, gynes, males, new cocoons, and brood area) between August 2012 and March 2013. We realized that while one colony collapsed and died after the males' and gynes' production, and the reduction of numbers of adult workers, in the other, a new queen assumed the posture at this phase and reactivated the old nest. Despite the reduced number of colonies investigated, this study shows the possibility of nest reactivation in the studied species in queen supersedure events in resemblance to perennial colonies of eusocial bees like Apis species and stingless bees. Such behavior has never been directly described to B. brevivillus in previous studies and opens the possibility for further research in the existence and the extension of perennial colonies in Neotropical Bombus species due to its importance to the species conservation in the tropical environment.

Identification of Aspergillus nomius in Bees Visiting Brazil Nut Flowers.

We designed a primer pair (BtubNomF/BtubNomR) specifically for amplifying Aspergillus nomius DNA. In vitro assays confirmed BtubNomF/BtubNomR specificity, corroborating its usefulness in detecting and identifying A. nomius. We then investigated the occurrence of A. nomius in floral visitors of Bertholletia excelsa trees by means of PCR, and A. nomius was detected in the following bees: Xylocopa frontalis, Bombus transversalis, Centris denudans, C. ferruginea, and Epicharis flava. The presence of A. nomius in bees visiting Brazil nuts opens up new avenues for obtaining novel insights into the process whereby Brazil nuts are contaminated by aflatoxin-producing fungi.