Pollen feeding by adults of the hoverfly Melanostoma fasciatum (Diptera: Syrphidae).
Pollen feeding by adults of Melanostoma fasciatum was studied in organic paddocks in New Zealand during 21 January-25 February 1994. Up to 6 different pollen types were found in one syrphid. On average, syrphids fed on 2.71 pollen species. The maximum score for pollen content in the gut was reached by 71% of gravid females, but only 13% of males. Of the 15 identified pollen groups, plantain, phacelia, coriander and graminaceous pollen were consumed in large quantities by gravid females. Differences in feeding spectra between sexes probably reflected the need for energy in males and for the protein required for egg maturation in females.