Tiger beetle larvae go through several instars, getting larger each time. They dig a hole in the sandin these observations, mostly in slightly moist sandand lie in wait for prey to wander by. The head and a thoracic shield fill the circular hole.
One abdominal segment is expanded and bears two large spines to anchor the larva in the hole.
dorsal view | lateral view
This structure probably allows the larva to resist being pulled out of the hole, but more importantly, allows it to jerk the headand the preyinto the hole.
When disturbed, the larvae disappear into the hole, only to emerge a few seconds later. Return of the Larva
Taking a cue from a bugguide.net page, I used a grass stem to fish a larva from a hole, photographed it on site and brought it home to photograph in the studio (4-6) (See bugguide.net). This instar is about 1.8 cm in length.
Note that I have named these larva images based on the adult tiger beetles seen in this location. I have only one photo of any species other than Cicindela oregona oregona in this location, at the mouth of the Elwha River. I have not identified the larvae independently.