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Genus Systropus

Bee Fly - Systropus bicornis wasp - Systropus angulatus Ammophila Mimic - Systropus macer Systropus arizonicus Systropus arizonicus Systropus sp - Systropus Systropus - Systropus angulatus Bombyliid - Systropus
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Diptera (Flies)
No Taxon (Orthorrhapha)
Superfamily Asiloidea
Family Bombyliidae (Bee Flies)
Subfamily Toxophorinae
Tribe Systropodini
Genus Systropus
Explanation of Names
Systropus Wiedemann 1820
4 spp. in our area (all in the nominate subgenus), 154 spp. in 4 subgenera worldwide(1)
adults have long slender abdomens, swollen near the tip; mimics of Ammophila wasps:
the nominate subgenus cosmopolitan, the other three (~a dozen spp. combined) are Afrotropical; in our area, S. macer in e. US (NH-GA-TX), the rest in sw. US (TX-AZ)(1)
Mostly on flowering shrubs
Mid-summer to early fall: in NC, S. angulatus Jul-Sep, S. macer Aug-Oct(2); in so. TX, Oct-Nov (unknown sp.)
Life Cycle
Larval hosts: caterpillars of Limacodidae, incl. S. macer on Parasa indetermina
An amazingly close Batesian mimic of digger wasps of the genus Ammophila; noted in one print reference (see below) as sympatric with certain species of that genus.
See Also
Conopidae, e.g. Physocephala
Syrphidae, e.g. Ocyptamus
Sphecid genus Ammophila (presumed model)
Print References
Epstein M. E. (1997) Parasa indetermina (Boisduval) (Lopidoptera: Limacodidae), a new host of Systropus macer Loew (Diptera: Bombyliidae). Proc. Entomol. Soc. Wash. 99(3): 585-586.
Zalom F.G., Meyer R.P., Mason P.H. (1979) Sympatric associations of Systropus spp. (Diptera: Bombyliidae) and Ammophila spp. (Hymenoptera: Specidae) in southeastern Arizona. Pan-Pac Entomol. 55: 239-240.