Identification: A distinctive, graceful, boldly-patterned species: All black or dark gray head and thoras with bold white, pale green or yellow-green stripe on the upper face (frons), a bold yellow-green stripe along the top of the thorax, and another yellow-green stripe along the side of the abdomen. The abdomen is nearly all black or dark gray. Abdomen narrow with a distinctively flared tip starting with S7 and then a much expanded with S10 being much wider than any other segment. Males have distinctive yellow cerci "grapples."
The yellow and black thorax pattern and clubbed tail are quite visible from a distance, making this species easily identifiable in flight.
Size: males 45-50 mm, females 44 - 45 mm. The overall impression of this species is of a medium-sized, light-weight, slender, graceful flier.
Habits: Grappletail are found near flowing water. They are classic perchers, spending much time on a favored rock, log or branch and sallying out to catch prey. They forage over streams or away from water.
Similar Species: Grappletails are quite unique, so there are no species that present identification challenges. They are vaguely similar to several other black-and-yellow species like Black Petaltail or Western River Cruiser. Both of those species show extensive yellow on the abdomen.
Distribution: Found along the west coast of North America from southern California to extreme southwest of BC. They occur in the coastal mountains and also in the second ranges including the Sierra Nevada and Cascades. This is a species of mountain and foothill streams.
Habitat: Grappletail prefer small, swift flowing streams. At the northern end of their range they prefer streams downstream from lakes in coastal mountains. In Southern California they prefer shaded foothill streams.
David Bell (06-21-2016)
