HIGH-INCIDENCE OF INFECTION OF AN UNDESCRIBED MICROSPORIDIUM (MICROSPORA) IN THE COMMUNAL BEE ANDRENA-SCOTICA (HYMENOPTERA, ANDRENIDAE)

We document the abundance and distribution of the spores of an undescr ibed species of microsporidium within its host, the communal bee Andre na scotica, and relationships between this parasite and its host, Only the host's adipose tissue (fat bodies) appeared infected, with up to 118 x 10(6) spores per bee. All hosts at one field site were infected. High spore load within hosts appeared to curtail female reproductive activity. However, we were unable to discern the microsporidium's effe cts on male fecundity in that some males with a high spore load did un dertake mate searching activity. Longevities of naturally infected A s cotica males and females in a flight cage were apparently unaffected b y the microsporidium. Spores were found in A scotica from other field sites but not in other species of bees, suggesting the microsporidium has a high degree of host specificity.