Boyeria McLachlan,1896 -DarnersNotes -Michigan SpeciesList - Key -References
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Page last updated: 26October 1998 (EB)
Notes on theMichigan Species of Boyeria
Both North American species - B. grafiana andB. vinosa- are found in Michigan (see Maps 1-2, below). A late-emerging genusin our area, larvae emerge usually in late June through August. Theselarvae are distinctive among our other aeshnids by the conspicuouslight blotch on the middorsum of the eight abdominal segment.
B. vinosa iscommonly encountered in quieter sections of streams and rivers (andrarely in wave-swept portions of lakes (EB, pers. obs.) throughoutMichigan, usually amongst accumulations of woody debris or organicleafy matter as well as under stones and submerged objects(Walker1958). Williamson(1932) stated that B. vinosa "is by all oddsthe most abundant and most widely distributed lotic Anisoptera eastof the Great Plains." Sampling from numerous localities in Michigancommonly yield two different size classes, indicating a two-year lifecycle for larvae (pers. obs.).Exuviae usually are found on exposedlogs and rocks as well as vegetation in and nearside the stream.B. grafiana only rarely has been collected in Michigan(Bright1997). Along the shore of Georgian Bay,Walker(1958) found larvae along the rockyshores of inland lakes or stream rapids, and exuviae were collected"on rocks, tree trunks or boathouses near the water and the teneralsfly first to a sheltered shady spot, such as a tree trunk, branch, ora cottage verandah." Although Walker stated that B. grafiana is principallya lake species in Ontario, and usually does not occupy the same sitesas B. vinosa, Perry(1977) found both species intributaries of the Grand River in Ohio. Larvae of B. grafiana "werecollected from Pierson Creek on 2 August 1974...[from] beneath smallstones in the more rapidly flowing portions of the main stream. Theywere placed in a simulated creek-bed set up in a laboratory aquariumand supplied with living mayfly and stonefly nymphs and crane flylarvae for food. A female grafiana emerged on 13August, 1974, followed by a male on 22 August. Another malegrafianawas taken in flight above Pierson Creek on 16 August, 1974."
Michigan SpeciesListMap 1Map 2
Map 1-2: County distribution of B. grafiana (Map1) and B.vinosa (Map 2) inMichigan
Click on map for a larger imageMap 1 - Boyeria grafianaWilliamson,1907- Ocellated Darner
Map 2 - Boyeria vinosa(Say,1839) - Fawn Darner
Key tothe Mature Nymphs of Michigan Boyeria
(References: Needham and Westfall1955; Walker 1958; Louton 1982)
1a. Prementumwidth about 0.66x of its length, folded labium clear short of theposterior margin of mesocoxae (Figure 1a1); Ab5-9 with lateral spines(Figure 1a2); epiproct often cleft, clearly shorter than paraprocts(Figure 1a3); cerci of female > 0.25x length of the paraproct -B. vinosa
Fig. 1a1 Fig. 1a2 Fig. 1a3
Fig. 1a1: (12x, ventral view), Boyeria vinosalarva, collected from the Black River, Cheboygan Co., Michigan, bythe Michigan Natural Features Inventory on 25 June 1996,UMMZODO-1297.
Fig. 1a2: Ibid, (12x, lateral view).
Fig. 1a3: Ibid, (25x, dorsal view).
1b. Prementumwidth about 0.60x of its length, folded labium extends to posteriormargin of mesocoxae, or beyond (Figure 1b1); abdominal segments 4-9with lateral spines, those on 4 usually very minute (Figure 1b2; notalways evident on earlier instars, and may be missing on someabnormal, mature specimens (see Wright 1949)); epiproct often pointed, as long as paraprocts(Figure 1b3); cerci of female < 0.25x length of paraproct -B. grafiana
Fig. 1b1 Fig.1b2 Fig. 1b3back totop
Fig. 1b1: Boyeriagrafiana larva, (12x, ventralview) from unknown locality, collector and date, UMMZODO-0337.
Fig. 1b2: Ibid (12x, lateral view).
Fig. 1b3: Ibid (12x, dorso-lateral view).
Bright, E. 1997. New larval Odonatarecords for Michigan. Williamsonia 1(2):10.
Louton, J. A. 1982. Lotic dragonfly(Anisoptera: Odonata) nymphs of the southeastern United States:identification, distribution and historical biogeography. Ph.D.thesis, University of Tennessee, Knoxville. 357 + xvii.
McLachlan, R. 1896. A new name forFonscolombia (pre-occupied). Annals and Magazine of NaturalHistory(6)17:424.
Needham, J.G. and M. J. Westfall, Jr. 1955. A Manual of the Dragonflies of NorthAmerica (Anisoptera). University of California Press: Berkeley,California. xii + 615 pp.
Perry, T. E. 1977.Boyeria grafiana, a rare Ohio dragonfly (Odonata: Aeshnidae).Great Lakes Entomologist 10:159-161.
Say, T. 1839.Descriptions of new North American neuropterous insects andobservations on some already described by (the late) Th. Say.Journal of the Academy of NaturalScience of Philadelphia 8:9-46.
Walker, E. M. 1958.The Odonata of Canada and Alaska, Vol. 2. University of TorontoPress: Toronto. xii + 318.
Williamson, E. B.1907. Two new North American Dragonflies (Odonata). Entomological News18:1-7.
Williamson, E. B.1932. Dragonflies collected in Missouri. University of Michigan Museum of Zoology, OccasionalPaper 240. 40 pp.
Wright, M. 1949.Notes on nymphs of the dragonfly genus Boyeria. Journal of the Tennessee Academy ofScience 24(3):213-215.back totop