Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar
BugGuide Gathering
Smoky Mountains
University of Tennessee Biological Field Station
August 8-10, 2008
Details...
 
Photos from the last gathering (Minnesota 2007)

TaxonomyBrowse
Info
ImagesLinksBooksData

Family Empididae - Dance Flies

Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Class Insecta (Insects)
Order Diptera (Flies)
No Taxon ("Orthorrhapha" (Brachycera excluding Aschiza and Schizophora))
Superfamily Empidoidea
Family Empididae (Dance Flies)
Other Common Names
Balloon Flies, Empids, Dagger Flies
Synonyms and other taxonomic changes
Marshall (1) states that family may be polyphyletic--some groups more closely-related to Long-legged Flies, Dolichopodidae.
Sometimes spelled Empidae.
Size
1.5-12 mm
Range
Worldwide.
Food
Tiny insects, and occasionally nectar as well. Larvae often feed on decaying vegetation or organic matter in the soil, some may be predatory.
Remarks
In mating swarms, males fly up and down in a sort of dance. They have captured an insect and wrapped it in silk, and hold it is an offering for females. Females seem to choose the male with the most enticing prey offering. Writers have recorded some instances of individual males cutting corners and offering only an empty ball of silk.

"About swarming:
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 a 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, Rhamphomyia and Hilara) (the latter including the balloon flies)." Paul Beck.
Print References
The Century Dictionary, entries for Empidae, Empis +(2)
Arnett, pp. 880-881 (3)
Borror and White (4)