Emeralds
Family Corduliidae
Genus Helocordulia
Uhler's Sundragon (Helocordulia uhleri)



Similar species � Beaverpond Baskettail (Epitheca canis), Spiny Baskettail (Epitheca spinigera), Common Baskettail (Epitheca cynosura).


Flight season: mid-May to early July.

Population: uncommon.

Length: about 40 mm to 45 mm. Females are similar to males. Separated from Epitheca (Baskettail) species by the black and amber spot at the base of the hind wings, and the cerci (males) or the subgenital plate (females).


Tweed, Ontario, the Moira River near the walking bridge and dam: rock-bottomed river with fast flowing water, rapids and emergent rocks, but also quiet pools and backwaters. The shoreline vegetation is mostly trees with a few small clearings supporting tall grasses and wildflowers.
Male Uhler's Sundragon (Helocordulia uhleri) � note the very hairy thorax. This individual was captured as it was patrolling over fast flowing water, defending its territory against other males (May 18, 2015).
Male Uhler's Sundragon (Helocordulia uhleri) � the black and amber spots at the bases of the hind wings are a distinguishing characteristic of this species (May 18, 2015).
Male Uhler's Sundragon (Helocordulia uhleri) � typical of many Emeralds, the eyes will turn green with increasing age (May 18, 2015).
Male Uhler's Sundragon (Helocordulia uhleri) � views of the claspers (May 18, 2015).





Tweed, Ontario, a vacant lot near the Louisa St. bridge over the Moira River: rock-bottomed river with a fast current, rapids and emergent rocks. The shoreline supports tall grasses, wildflowers, shrubs and some trees.
Images of a male Uhler's Sundragon (Helocordulia uhleri) and its termilaia (May 21, 2016).