Aquatic Insects of Michigan by Ethan Bright, Museum of Zoology Insect Division and School of Natural Resources and Environment |
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Celithemis (Libellulidae) (Small Pennants) of Michigan - IdentificationThis group of attractively winged dragonflies are often familiar to almost everyone. Eight species of Celithemis are distributed in eastern North America (one extends west into the southwest), three species are found in Michigan. Adults of our species have beautifully patterned wings and have a characteristic perching pattern on the tops of vertical stalks. Nymphs are clean, medium-sized, thin-legged, and delicate greenish and brown banded, they can be active on submerged vegetation or hiders among roots. Nymphs are distinguished from our other libellulids by the lack of middorsal spines on abdominal segment 8, and the long lateral spines of abdominal segments 8 and 9, the latter of which are twice the length of segment 8 and extend to or past the tips of the paraprocts. In fact, these characters together with the rather long length of the cerci (about 0.5x length of the paraproct) and the rather truncate shape of the end of the abdomen may confuse some with corduliids. However, Celithemis lack a distinct longitudinal medial groove at the base on the ventral surface, and the margin of the lateral lobes of the prementum are only finely crenate, with dentations much less pronounced than other corduliids. Both C. elisa (Hagen, 1861) and C. eponina (Drury, 1773) are widely distributed in both peninsulas, whereas records for C. fasciata (Kirby, 1889) exist only for the southern LP. Nymphs are often found in lakes and ponds with aquatic vegetation, though sometimes specimens are taken from still or slow-moving sections of streams among macrophytes. In Michigan the emergence of adults occurs in June through early July, and exuvia are often found clinging to vegetation emerging up from water (Leonard 1934, pers. obs.). Life cycle of Celithemis is univoltine (Benke & Benke 1975, Wissinger 1988, Bright pers.obs). Taxonomic references: Needham et al. 2010, Paulson 2011, Tennessen 2019, Walker and Corbet 1975 Adults
Mature Nymphs
References
Page created: July 17, 1998 - Last updated: April 22, 2020 (EB) |