Libellula Linnaeus, 1758 - Skimmers
(underconstruction)Pagelast updated: 18 November 1999
Notes on theMichigan Species of Libellula
The genus Libellula is a common,widespread, and diverse genus of principally Holarctic dragonflies.Twenty-one species are known from North America north of Mexico, withseven species (not including Ladonajulia and Plathemis lydia, seebelow) occuring in Michigan.
The traditional placement of Ladona and Plathemis withinLibellulahas not been universally accepted. Many authors (e.g., Bennefield1965, Borror 1945, Walker and Corbet1975, Garrison 1991) retain the classification of Ris (1910) and Kennedy (1922) in delegating Ladona and Plathemis as subgenera ofLibellula,based principally upon the similarity of adult features of the formertwo to a Palaearctic Libellula. Others (e.g.,Carle1978, May 1992; Schmidt 1987; Westfall andTennennsen 1996), however, followNeedham's1897 generic ranking of Ladona and Plathemis. Among otherreasons, there are distinct differences in larval morphology(premental setae and outline of, and position of setae within, theapical margin of prementum, crenations on medium lobe of prementum)which clearly distinguish these three taxa. Knopf (1977) separates the three genera based upon electrophoreticdata, although that study is limited by a small sample size. A recentstudy by Ralph Charlton and Srinivas Kambhampati has attempted toresolve the issue by examining mitochondrial 16S ribosomal RNA gene,and applying a cladistic analysis. Based on the examination of ~415bp DNA sequences from 23 taxa, the authors argue that "Ladona andPlathemisare monophyletic lineages distinct from Libellula s. str. with asister group relationship between Libellula andLadona. Wetherefore propose that Ladona and Plathemis be consideredgenera within Libellulidae but distinct from Libellula" (Charlton andKambhampati, ESA abstract, 1997). I (EB) believe the evidence forseparation is strong, hence Ladona and Plathemis are treated apart from Libellula, and are keyedout separately in the genus key toLibellulidae.
All six species of Libellula in Michigan canbe found in ponds, small lakes or bays, and quiet river margins.L. pulchella appears to have a preference well-buffered waters incalcareous soils, and avoids peaty waters (Walker and Corbet 1975).L. quadrimaculata, on the other hand, appears to prefer the peaty watersof marshes and bogs. L.semifasciata also is found in forestedbrooks and ponds, marshy bays and seepage ditches. L. vibrans has recently(1999) been added to our state list, with an adult being netted insoutheastern Michigan.
Other links with information on the biology orecology of larval Libellula:
Briefhabitat notes on Ottawa, Ontario, Canada Libellula>>http://www.geocities.com/Vienna/Studio/1714/odon2.html
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Libellula cyanea Fabricius,1775 - Spangled Skimmer
Libellula incesta Hagen,1861 - Slaty Skimmer
Libellula luctuosa Burmeister,1839 - Widow Skimmer
Libellula pulchella Drury,1773 - Twelve-spotted Skimmer
Libellula quadrimaculata Linnaeus, 1758 - Four-spotted Skimmer
Libellula semifasciata Burmeister,1839 - Painted Skimmer
Libellula vibrans Fabricius, 1793 - Great Blue Skimmer
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Key tothe Mature Larve of Michigan Libellula
1a. Lateral setae lessthan 7 - 2
1b.Lateral setae 7 or more - 4
2a(1a). Epiproct distinctly decurved to the tip;premental setae 8-9 - 3
2b. Epiproct not as above, being straight oronly slightly decurved apically; premental setae 10-11; no middorsalhook on Ab3 - L. vibrans
3a.(2a). Mature larvae not greater than 22 mm in length;cerci about 0.5x length of paraprocts - L. cyanea
3b. Maturelarvae about 26 mm in length; cerco about 0.33x length of paraprocts- L. incesta
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4a.(1b). Palpal setae 8 or 9 (picture); dorsal hook absenton abdominal segment 8 - L.pulchella
4b. Palpalsetae 7 or 8 (picture); dorsal hook present on abdominal segment 8 -5
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5a.(4b). No dorsal hook on abdominal segment 3 -L. luctuosa
5b. Dorsalhook present on abdominal segment 3 - 5
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6a.(5b). Premental setae (on each side) 10-14 (picture);largest dorsal hook on abdominal segments 5, 6 or 7 (picture); cerciabout 0.7x as long as paraprocts (picture) - L. quadrimaculata
6b. Premental setae (on each side) 16 (picture); largestdorsal hook on abdominal segment 8 (picture); cerci about 0.5x aslong as paraprocts (picture) - L.semifasciata
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Bennefield, B. L.1965. A taxonomic study of the subgenus Ladona (Odonata:Libellulidae). University of KansasScience Bulletin 45:361-396.
Borror, D. J. 1945. Akey to the New World genera of Libellulidae (Odonata).Annals of the Entomological Society ofAmerica 38:168-194.
Burmeister, H.1839. handbuch der Entomologie. Vol 2. Enslin: Berlin. pp.397-1050.
Carle, F. L. 1978.Progress on taxonomic and nomenclatural problems of VirginiaAnisoptera: a reply to Dennis R. Paulson. Selysia 8(1):13-14.
Drury, D. 1773.Illustrations of natural history. Vol. 2. White: London. 90pp.
Fabricius, J. C.1775. Systema entomologiae. Libraria Kortii: Flensburg & Leipzig.424 pp.
Garrison, R. W.1991. A synonymic list of the New World Odonata. Argia 3(2):1-30.
Hagen, H. A. 1861.Synopsis of the Neuroptera of North America, with a list of the SouthAmerican species. SmithsonianMiscellaneous Collections4:1-347.
Kennedy, C. H. 1922.The morphology of the penis in the genus Libellula (Odonata).Entomological News 33:33-40 + 2 pls.
Knopf, K. W. 1977.Protein variation in Gomphus(Odonata: Gomphidae). Unpublished Ph.D.thesis, University of Floridae, Gainesville. vi + 107 pp.
Linne, C. 1758.Systema naturae. Editio decima reformata. Holmiae. 543 pp.
May, M. L. 1992.Morphological and ecological differences among species ofLadona (Anisoptera: Libellulidae). Bulletin of American odonaology 1(3):51-56.
Needham, J. G.1897a. Libelluladeplanta of Rambur. Canadian Entomologist 29:144-146.
Ris, F. 1910.Collections zoologiques du Baron Edm. de Selys Longechamps. Cataloguesystematique et descriptif. Fascimile XI. Libellulinen 3. 1:245-384 +1 pl.
Schmidt, E. 1987.Generic reclassification of some Westpalaearctic Odonata taxa in viewof their Nearctic affinities (Anisoptera: Gomphidae, Libellulidae).Advances in Odonatology 3:135-145.
Walker, E. M.and J. S. Corbet. 1975. The Odonata of Canada and Alaska, Vol. 3.University of Toronto Press: Toronto.
Westfall,M. J., Jr. and K. J. Tennessen. 1996. Odonata, pp. 164-211.InMerritt, R. W. and K. W. Cummins (eds.), An Introduction to theAquatic Insects of North America, 3rd Ed. Kendell/ Hunt PublishingCompany: Dubuque, Iowa.
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