Identification
The Clubtails, Family: Gomphidae, is a distinctive group of odonates containing 98 species in NA of which most are Eastern. Identification to species is not always easy. Grouping the species into Genera and Sub-genera helps to narrow down the choices when attempting an identification. Dunkle divides the Genus: Gomphus ino 4 Sub-genera: Gomphus (Gomphus), Gomphus (Phanogomphus), Gomphus (Stenogomphurus), Gomphus (Gomphurus).
I. Gomphus (Phanogomphus)
The 17 members of this sub-genus are regarded as medium in size, slender, and with small to moderate-sized clubs (S8 & S9) in males, barely present in females. All species have yellow patches on the club and yellow dorsal markings on most of the abdominal segments. All have brownish thoraces with 2 yellow lateral stripes. The species range across NA except for the dry West. Identification to species is not always easy. The shape and extent of the dorsal markings along with the shape of the terminalia in males are the best way for a definitive ID. The restricted distribution for some of the species helps in their ID. They are all illustrated on Plates 7 & 8 in Dunkle
(1).
The 6 widespread eastern species of these Clubtails: Ashy, Beaverpond, Dusky, Harpoon, Lancet, and Rapids are not always identifiable from photographs. Clear dorsal and lateral photos of a specimen, and dorsal and lateral close-up views of male terminalia would be a significant contribution to BugGuide viewers who wish to ID members of this sub-genus. With such a goal in mind I am posting close-up views of male terminalia of the Lancet Clubtail
here. Nikula
(2) illustrates the terminalia of all the 6 widespread eastern species
(Tony Thomas-9i06)
