Orobittacus obscurus Villegas & Byers, 1981
Diagnosis: This species has smoky brown wings. However, the most striking features are in the male genitalia. The cerci are longer than the basistyle and broadly spatulate. The ninth sternite and tergite are fused, forming a continuous ring. There is a medial, dorsal, caudal projection from the ninth tergite with a series of stout apical teeth. The dististyles are bifurcated with the medial branch upturned and tubular.
Distribution – Geographical: This species is only known from two small populations along the American River and Shirttail Creek in El Dorado and Placer Counties, California, along the lower slopes of the Sierra Nevada.
Distribution – Temporal: Adults have been collected between 10 May and 4 July, with the majority collected in early June.
Ecology: The habitat of this species is boulder-strewn forests along the edges of the streams. Individuals can be found mostly clinging to roots or under overhangs of the rocks in shadowed areas.
Biology: Nothing is known of the immature stages of this species. Attempts to sequester adults for egg-laying have proven futile. Most have died within 24 hours.
Notes: The discovery of Orobittacus obscurus came as quite a surprise to students of Mecoptera because no other bittacid had been discovered in North America in more than 100 years, and it came in a state with many entomological enthusiasts collecting in the field. Its obscurity was due to its restricted geographical distribution and cryptic habits.
This is no ordinary bittacid. The male genital morphology is completely unlike that of any other species in North America, and in fact show elements of an ancient Gondwanian relationship. This species was considered by Villegas & Byers to have much in common with characteristics of Tytthobittacus from Australia and Anabittacus from Chile. The biogeographical implications are intriguing.
The name Orobittacus is derived from the Greek “oros” meaning mountain, and the Spanish “oro” meaning gold, a reference to the discovery of gold close to the type locality in 1848. The term “obscurus” refers to the dark wings and the behavioral patterns of keeping to the deep shadows where they are hard to see.
Villegas, B. and G.W. Byers. 1981. Orobittacus obscurus, a new genus and species of Bittacidae (Mecoptera) from California. Pan-Pacific Entomologist, 57(3):385-396, 11 figs.