Macromia Rambur, 1842 - River cruisers


Notes - MichiganSpecies List - Key -References
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Page last updated: 12August 1998

Notes on the Michigan Species of Macromia

Two of the 7 species of Macromia found in NorthAmerica north of Mexico have been collected in Michigan (see mapsbelow). M. illinoiensis is by far the most common species, and is foundthroughout the state. M.taeniolata is know by only a few adultspecimens in the southern LP.

Williams(1978) noted that larvae ofM. taeniolata collected from Texas fed chiefly during night, whileduring the daylight hours lay burrowed in mud or debris substrates. Arecent adult specimen from the Ann Arbor, Washtenaw County in the LPappeared to be flying about the shore of the Huron River (MarkO'Brien, pers. comm.). The river there is slow-moving, with fine siltand gravel substrate with the shore with large-rooted willow trees.Walker andCorbet (1975) found larvae ofM. illinoiensis in large, somewhat rapid streams as well as moderatelywave-swept sections of lakes. I (EB) have found larvae ofM. illinoiensis in the UP sprawling in sandy and rocky substrates ofclean, well-aerated lakes as well as in similar substrates ofslow-moving streams. Larvae from these habitats appear golden brownwith a dark, speckled pattern, and when placed on these substratesappear quite cryptic. Huggins (in Huggins and Brigham1982) found larvae of M. illinoiensis fromKansas also among hanging masses of rootlets and aquatic vegetation.Larvae emerge in June through early July in Michigan.

Needham andWestfall (1955) provided the firstcomprehensive taxonomic treatment for larvae, but the character usedto separate M.illinoiensis from several other species(shape of lateral spine of Ab9) is considered unreliable(Donnelly andTennessen 1994). Alternative diagnosticcharacteristics have since been suggested that allow for speciesdifferentiation (Huggins and Brigham1982, Donnelly andTennessen (1994), upon which the keybelow is based.

Other links with information on the biology orecology of larval Macromia:
none found as of 01 February 1998

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MichiganSpecies List

Map 1Map 2
Maps 1-2: County distribution of the Michigan species of
Macromia
Click on map for a larger image

Macromiaillinoiensis Walsh, 1862 - Illinois River Cruiser - Map 1
Macromia taeniolata Rambur, 1842 - Royal River Cruiser - Map 2

Key to the Mature Nymphs of Michigan Macromia
Based on Huggins and Brigham1982 and Donnelly andTennessen (1994)

1a. Maturelarvae large, total length > 33 mm; mid-dorsal abdominal hook on 6stout, its width-to-height ratio greater than 0.80 (picture); heightof mid-dorsal hook on Ab2 usually shorter (< 0.85x) than that onAb3 (figure); frontal horn blunt (figure) - M. taeniolata

1b. Maturelarvae smaller than above, total length < 30 mm; mid-dorsalabdominal hook on 6 more slender than above, its width-to-heightratio less than 0.65 (0.62-0.64) (picture); height of mid-dorsal hookon Ab2 nearly (> 0.9x) as high as that on Ab3 (picture); frontalhorn sharp (figure) - M.illinoiensis

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References

Donnelly,T. W., and K. J. Tennessen. 1994. Macromia illinoiensis andgeorgina:a study of their variation and apparent subspecific relationship(Odonata: Corduliidae). Bulletin of American Odonatology2(3):27-61.

Huggins, D.G. and W. U. Brigham. 1982. Odonata, pp. 4.1-4.100 in Aquatic Insectsand Oligochaetes of North and South Carolina. Brigham, A. R., W. U.Brigham and A. Gnilka, eds. Midwest Aquatic Enterprises: Mahomet,Illinois.

Rambur, J. P. 1842. Histoire naturelledes insectes neuroptères. LibraireEncyclopédique de Roret, Paris. 534 pp.

Walsh, B. D. 1862.List of the Pseudoneuroptera of Illinois contained in the cabinet ofthe writer, with descriptions of over forty new species, with noteson their structural affinities. Proceedings of the Academy of Natural SciencesPhiladelphia 14:361-402.

Williams, C. E.1978. Notes on the behavior of the late instar nymphs of fourMacromiaspecies under natural and laboratory conditions (Anisoptera:Macromiidae). Notulae Odonatologicae1(2):27-28.

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