POLLEN FEEDING BY ADULTS OF THE HOVERFLY MELANOSTOMA-FASCIATUM (DIPTERA, SYRPHIDAE)

Pollen feeding by adult hoverflies of Melanostoma fasciatum, collected from organic paddocks at Flock House, Bulls, North Island, New Zealan d, were studied by dissection. Up to six different pollen types were f ound in one hoverfly. On average, they fed only on 2.71 pollen species . 71% of gravid females but only 13% of males reached the maximum scor e (scale 0-5) for pollen content in the gut. Very few hoverflies had n o pollen. Of the 15 identified pollen groups, plantain, phacelia, cori ander, and graminaceous pollen were consumed in large quantities by gr avid females. Differences in feeding spectra between sexes probably re flected the need for energy in males and for the protein required for egg maturation in females. Earlier views of strict preference for anem ophilous pollen by M. fasciatum cannot be upheld.