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Genus Boreothrinax

Pyrgotid Fly - Boreothrinax maculipennis pyrgotid - Boreothrinax Mottled-winged fly - Boreothrinax maculipennis Acalyptratae Fly - Boreothrinax maculipennis Pyrgotid Fly - Boreothrinax maculipennis bug - Boreothrinax maculipennis Fly attracted to UV light - Boreothrinax Boreothrinax maculipennis? - Boreothrinax
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Diptera (Flies)
No Taxon ("Acalyptratae")
Superfamily Tephritoidea
Family Pyrgotidae
Genus Boreothrinax
Synonyms and other taxonomic changes
Boreothrinax Steyskal 1978
3 spp. in our area:
  B. dichaetus Steyskal, 1978 -- Arizona, Mexico
  B. maculipennis (Macquart) -- eastern states west to AZ
  B. shewelli Steyskal, 1978 -- BC to CO
The two principal characters distinguishing the genus Boreothrinax from its closest relative, the genus Sphecomyiella, are:
  1) a strongly constricted basal 1/3 of the hind tibia; and
  2) the absence of a strong hooked apico-ventral claw on the female terminalia.
Other characters involving post-ocellar bristles and pleural setation also helped separate some of the species...see lines 9) and 10) of Steyskal's key for details. Still other characters not stated in Steyskal (e.g. strongly banded tibiae in Boreothrinax, and the extent of spots and stripes on the head in Sphecomyiella) seem to differ fairly consistently among the two genera.
NOTE: From the first BugGuide post of this species on 4/28/05 until 9/22/13, this node in the BugGuide taxonomic tree was listed under the incorrect name "Pyrgota" maculipennis. See this forum for details on this issue. All the images previously under "Pyrgota" maculipennis on BugGuide have now been moved to this guide page under the corrected name.
See Also
Sphecomyiella and Boreothrinax are often confused with one another...see "Item 2)" in this BugGuide forum for further info.
Print References
Steyskal G.C. (1978) Synopsis of the North American Pyrgotidae (Diptera). Proc. ent. Soc. Wash. 80: 149-155 (Full Text)