Stylogomphus Fraser, 1922 - Least clubtail
Stylogomphus albistylus (Hagen in Selys, 1878) - Least Clubtail


Fig. 1: S. albistylus larva collected from Mountain Stream,
Marquette Co., Michigan, USA, on 30 June 1996 by Bright, O'Brien and Kielb
UMMZ Collection

Notes - References
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Page last updated: 14 July 1998 (EB)

Notes on Stylogomphus albistylus in Michigan

Until 1996, Stylogomphus albistylus had been known from only one locality in the northern part of the Lower Peninsula (Leonard 1940). Recently, several large populations of both adults and larvae have been found in the Upper Peninsula (Yanoviak 1993, Kielb et al. 1996, Bright 1997), and S. albistylus undoubtedly is more widespread there based on its frequency in northern Wisconsin (Hilsenhoff 1995) (see Map 1). Several adult and larval specimens have come from streams in the northern Lower Peninsula, and there is also one unverified larval record from Oakland County (Bidlack, pers. comm.).


Map 1: County distribution of Stylogomphus albistylus
Click on map for a full-sized image

Stylogomphus larvae (Fig. 1, above) are distinctive from our other gomphids by its small size and spatulate-shaped third antennal segment with the inner margin straight (Hagenius larvae are considerably larger, with very flat abdomens and large tubercles on the head; Lanthus is not found in Michigan). Larvae apparently prefer rocky, clean streams with considerable gradient. Based on the range of larval sizes from samples collected from Marquette Co. in 1996 (< 3 mm to 19.3 mm), this species appears to require more than one year to complete its larval stage in this part of its range. Emergence in this part of its range occurs in late June during late morning and early afternoon, with larvae crawling from a well-shaded stream upon rocks and stream-side plants, with adults soon (within 15 minutes) thereafter emerging (Kielb et al. 1996, Bright 1997).

Other links with information on the biology or ecology of larval Stylogomphus:
none found so far (10 January 1998)


References

Bright, E. 1997. New regional records for Michigan. Williamsonia 1(4):3

Fraser, F. C. 1922. New and rare Indian Odonata in the Pusa Collection. Memoirs of the Department of Agriculture in India, Entomological Series 7(7):39-77.

Hilsenhoff, W. L. 1995. Aquatic insects of Wisconsin. Keys to Wisconsin genera and notes on biology, distribution and species. (3rd Ed.). Publication Number 3 of the Natural History Museums Council, University of Wisconsin-Madison (1995).

Kielb, M. A., E. Bright, and M. F. O'Brien. 1996. Range extension of Stylogomphus albistylus (Odonata: Gomphidae) for the Upper Peninsula of Michigan. The Great Lakes Entomologist 29(2):87-88.

Leonard, J. W. 1940. Lanthus albistylus (Hagen), a new record for Michigan, with ecological notes on the species (Odonata: Gomphinae). Occasional Papers of the Museum of Zoology, University of Michigan, No. 414. 6 pp, 1 plt.

Selys-Longchamps, E. de. 1878. Quatriemes Additions au synopsis des Gomphines. Bulletin de l'Académie royale des Sciences de Belgique (2)46:408-471, 658-698.

Yanoviak, S. P. 1993. A comparison of benthic macroinvertebrate assemblages in lake-outlet and dendritic streams of the Huron Mountain Region of Michigan. Unpublished MS Thesis, Purdue University.