Explanation of Names
Greek rampho 'beak' + plus myia 'fly'
~150 described spp. in our area(1)
+ at least 400 undescribed; 450 described spp. worldwide[cite:745518]
Similar to Empis, but wing venation different
n. hemisphere [cite:745518], incl. much of North America
Moist areas, along edges of fresh (and salt?) water.
Noted, as are other genera of this family, for forming mating swarms. Males capture a small insect and offer it as a nuptial gift to a female.
1. You may have male swarms, female swarms and mixed swarms. In the case of the first two it may be that the other sex does not form swarms but joins the existing swarm for mate selection, or there are nearby separate swarms and specimens from one of those leave for the other to select a mate.
2. Different species swarm at different times of day. Some may swarm during the whole day, others maybe only for an hour at dusk, etc.
3. The location of the swarm is determined by markers. These may be very specific (under a overhanging branch in the sun, so the swarms may move with the sun) or rather 'generally defined' (along a slope, creating a very 'long' swarm, or over the water surface in a brook).
4. Nuptial gifts are not known for all mating dance flies. They are mostly found in the Empididae Empidinae (in genera like Empis
) (the latter including the balloon flies). Comment by Paul Beck