Aquatic Insects of Michigan

by Ethan Bright, Museum of Zoology Insect Division and School of Natural Resources and Environment
University of Michigan

Plathemis Hagen, 1861 (Libellulidae) (Whitetails) of Michigan - Identification

Plathemis is a genus of two species, of which one - P. lydia (Drury, 1773) - is widespread in North America and is found throughout Michigan. Nymphs are dark green to brown, stout, robust and often covered in detritus due to its sprawling habit in softer substrates. They inhabit both ponds and sheltered inlets of lakes as well as pool segments of streams. In Michigan adults emerge generally in very late May through the first half of June. The body form of the adult is stout, with a somewhat dorsoventrally compressed abdomen. Males are striking in their appearance with wings having one dark brownish-black basal marking and another more distal black band on an otherwise hyaline wing, and a bright white abdomen (may fade with age). Females wings have three brownish marks: a narrow basal mark extending from the wing attachment to the triangle, an incomplete midwing band that is almost triangular in shape, and a complete band covering the wingtip. Females somewhat resemble Libellula pulchella, but can be differentiated from that species by the yellowish zigzag pattern on the abdomen. Nymphs are distinguished from other species of Libellula by the curved, crenated premental front margin that have small setae within the notches, and from Ladona julia by the the presence of more than 9 premental dorsal setae (3 or less in Ladona), the lack of mid-dorsal spines on abdomenal segments 7 and 8 (present in Ladona julia), and the abdomen with dark, longitudinal stripes (absent in Ladona julia). Levine (1957) gives a minutely-detailed morphological description of the larva and a key to differentiate between the two species of Plathemis (P. lydia and P. subornata).

The taxonomic placement of Plathemis with regards to Libellula and Ladona (and other closely related taxa) is discussed on the page for Libellula.

Life cycle is generally univoltime (Wissinger 1988). One specimen collected by Ed Kormondy in the Maple River, Emmet Co. in the northern LP on 20 August 1953, has well-developed wing pads, suggesting either another population with late emergence, or nymphs may exhibit developmental diapause until emergence the following year.

Taxonomic references: Needham et al. 2010, Paulson 2011, Walker and Corbet 1975

Bick GH. 1950. The dragonflies of Mississippi (Odonata: Anisoptera). American Midland Naturalist 43:66-78.
Craves JA, O'Brien D. 2011. Tramea calverti (Odonata: Libellulidae): New for Michigan with notes on other new reports for the Great Lakes Region. The Great Lakes Entomologist 44(1-2):78-82.
Musser RJ. 1962. Dragonfly nymphs of Utah (Odonata: Anisoptera). University of Utah Biological Series 12(6):1-66.
Needham JG, Westfall MJ, May ML. 2010. Dragonflies of North America, Third Edition. Scientific Publishers, Gainesville, Florida, USA. xiv + 657 p.
Paulson D. 2011. Dragonflies and damselflies of the East. Princeton Field Guides. Princeton University Press, Pinceton, New Jersey, USA. 538 p.
Walker EM, Corbet JS. 1975. The Odonata of Canada and Alaska, Vol. 3. University of Toronto Press: Toronto, Ontario. xvi + 308.
Drury, D. 1773. Illustrations of natural history. Vol. 2. White: London. 90 pp.
Hagen, H. A. 1861. Synopsis of the Neuroptera of North America, with a list of the South American species. Smithsonian Miscellaneous Collections 4 (1862). 347 pp.
Levine, J. R. 1957. Anatomy and taxonomy of the mature naiads of the dragonfly genus Plathemis (Family Libellulidae). Smithsonian Miscellaneous Collections 134(11):1-28.
Wissinger, S.A., 1988. Spatial distribution, life history and estimates of survivorship in a fourteen- species assemblage of larval dragonflies. Freshwater Biology 20: 329-340.

Page created: July 17, 1998 - Last updated: February 17, 2017 (EB)