Swarming Bevahiour in Sciara hemerobioides

Sciara hemerobioides swarming

A subject of a previous post, Sciara hemerobioides, was recently observed swarming around False Oat Grass (Arrhenatherum elatius), seemingly feeding on the seeds of the grass, in a coastal area. I find this quite odd, as any references I have found to adult S. hemerobioides feeding have put then feeding on the nectar of umbelliferous plants (1) and adults can only ingest liquids. No mating, or interest in mating, was observed in any of the flies. The all seemed to be actively feeding at the grass seed head.

Sciara hemerobioides swarming

References:

1. Menzel et al., 2006. Zoological Journal of the Linnean Society 146 pp. 1-147