On a recent trip up to central Oregon, at a rest area along the Rogue River there were several giant California stoneflies (Pteronarcys californica). This is the largest species of stonefly in the world. Common along my stretch of the Van Duzen River, I recognized them immediately. They are totally harmless and their presence indicates good water quality. Knowing they’re out and about indicates there may be good fishing in an area.
A helpful hint: Snapping photos of things others either can’t see or don’t notice around public restrooms can get you some strange looks.
The big robber flies that abound up there — easily an inch and a half long — are the local aerial insect predator. While flying, their wings made a loud, deep buzz. I suspect the presence of a farm with large animals, dung and the creatures attracted to it, drew these ugly hunters.
True flies (member of order diptera, family asilidae), these guys can, if mishandled, deliver a painful bite, injecting a cocktail of neurotoxins and digestive enzymes designed to paralyze then liquify their prey’s innards to be sipped out through specially evolved mouthparts.
I watched as one struggled to fly with prey as large as itself, finally settling among the weeds. At first I thought it might have a cicada, but soon realized it was dining on one of its own. Yes, aside from being hideous, they’re cannibals too.
At another rest area in Central Oregon I spotted some gray and black caterpillars as large as my index finger crawling down the trunks of several pine trees. It turns out they are the larvae of the Pandora moth. During heavy infestations, they can denude entire trees or even swaths of trees and have been cited in many references as a Native American foodstuff of note.
This article appears in ‘Highway Robbery’.