We have photographed these shield-backed kadydids since 2008 at several locations in Olympic National Park: Sunrise Ridge trail, Obstruction Point Road, Blue Mountain and the Elwha Trail, west of Hurricane Hill.

All the specimens we’ve photographed are females—note the long ovipositor. The same is true for individuals we’ve seen with butterfly binoculars, all female. All the nymphs—at several stages—we’ve photograhped are also females, even the very earliest instars. Some kadydid populations are known to be parthenogenetic, so this population may also be parthenogenetic. Other populations are mostly parthenogenetic, but occasionally males are hatched.

This species has much reduced wings in the adult, a characteristic pattern on the thorax, and adults are nearly 3 centimeters long, excluding the antennae and ovipositor.

The genus is probably Steiroxys, and the species may be undescribed. (See Bugguide.net page)

It’s possible that these are Sterioxys trilineata, with unusual patterns. See photos of S. trilineata at University of Florida and on bugguide.net). A 1907 publication of the United States National Museum (download pdf) describes S. trilineata and includes a figure (slide 15).