Stonebrood. An emerging disease for Argentine wild bees?

SOLIS AILEN A. ; ALVAREZ LJ; TIZZANO MA; DELLA VEDOVA R; LUCIA M; REYNALDI FJ

Santiago de Chile

Congreso; 48° APIMONDIA Congress; 2023

APIMONDIA

Bees were the most important group of pollinators worldwide, but in the last fifteen year their decline has become a growing problem. Several factors, such as habitat loss, pesticides, climate change, parasites and diseases and their interactions were the most important ones. In Argentina very few information is available. Related to bee pathogens that affect wild bees, only sporadic reports were available in the last years, but no reports of stonebrood (Aspergillus flavus) affecting bees were informed. As fungi are the aetiological agents that are less frequently reported, they receive very little attention and are understudied in scientific research.. Moreover, (A. flavus) compared to other fungal diseases such as chalkbrood, caused by Ascosphaera apis, it is considered of minor importance in apiculture. However, this fungus is the second most reported cause of human aspergillosis. We study twenty-six brood cells nest of a nest aggregation of Melitoma segmentaria and Ancyloscelis halictoides located in a vertical clay bank located on artificial hill of approximately 1m high and an area of 16m2 in Berisso, Buenos Aires (-34.8607, -57.8756). Brood cells dead were opened, and all samples were processed in order to eliminate any possible superficial fungal agents. Later, samples were cut in pieces and cultured on YGPSA (yeast extract 10 g, glucose 10 g, KH2PO4 13.5 g, soluble starch 10 g, and agar 20) for 21 days at 37 °C in darkness. We isolated in fourteen samples A. flavus, identify by macromorphological, micromorphological, PCR assays, sequencing and BLAST identification. Aspergillus flavus have been reported, sporadically, affecting honeybee of Argentina. To our knowledge this is the first report of A. flavus affecting wild bees in Argentina.