Unicorn Clubtail
Arigomphus villosipes
Selys, 1854
Order Odonata
Suborder Anisoptera
Superfamily Gomphioidea
Family Gomphidae
Genus Arigomphus
Species villosipes (Selys, 1854) [Gomphus]
Identification
This is a slightly larger darker species with a prominent sharp elevation or spine in the middle of the occiput that is usually edged by black. It is largely green with a relatively well-marked thorax and predominately dark abdomen. The dark brown middorsal thoracic stripe is divided by a pale carina, except at its upper end.
The humeral and antehumeral stripes are both present and well-developed and separated by a green stripe of about equal width. The humeral stripe is abbreviated and free at its upper end. The remaining mid- and third lateral stripes are only visible at their ends. The hind femora of the male are densely clothed with a series of hairs. The abdomen is largely black, especially distally. The pale greenish middorsal stripe is interrupted on segments 3-7. Segments 8-9 are nearly all black and 10 and the caudal appendages are yellowish-brown.
Size
Total length: 50-58 mm; abdomen: 37-41 mm; hindwing: 29-36 mm.
Similar Species
The distribution and prominent spine at the middle of the occiput are unique for the pond clubtail species in the area.
Habitat
Semi-permanent and artificial ponds, lakes and slow-areas of small streams with muddy bottoms.
Discussion
A single record of this eastern species exists in the region. It commonly rests on wet pond edges, rock and logs, where it can be extremely difficult to approach. It is apparently proficient at taking and feeding on smaller dragonflies.
Distribution
Generally northeastern from Ontario southward to Arkansas.





