Plathemis is a genus of two species, of which one - P. lydia - is widespread in North America and is found throughout Michigan (Map 1).
These are stout, robust smooth larvae which inhabit both ponds and sheltered inlets of lakes as well as pool segments of streams. Adults emerge in very late May through the first half of June. 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, indicating either another population with late emergence, or larvae that may exhibit developmental diapause until emergence the following year.
Closely related to Libellula and Ladona, some researchers prefer to retain Plathemis within Libellula (see discussion under Libellula). Larvae of Plathemis are distinguished from other Libellula by the curved, crenated premental front margin that have small setae within crenation notches (picture), and from Ladona by the the presence of more than 9 premental dorsal setae (3 or less in Ladona) and the lack of mid-dorsal spines on abdomenal segments 7 and 8 which also often show dark, longitudinal stripes (picture). 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).
Other links with information on the biology or
ecology of larval Plathemis:
none found so far (15 January 1998)
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.