Graphopsocus cruciatus

Here’s a photograph of a narrow barklouse (Graphopsocus cruciatus) with a clutch of eggs. It was December 18th and cold, but apparently this group of insects (Stenopsocidae) are known to be active in winter.

Narrow barklouse (Graphopsocus cruciatus) with clutch of eggs. Domed object is spider egg case. Tinicum, PA.

Here’s a closeup of the eggs so you can see the silk that holds them down. I watched her apply this webbing (from labial silk glands) for about 15 minutes. Some species in this group are gregarious and can cover an entire tree in webbing.

Narrow barklouse (Graphopsocus cruciatus) eggs.

I don’t think the larvae will eat the egg case (a spider’s, I think). Barklice are reported to eat fungi, algae, lichens, plant tissue, and pollen, but there doesn’t seem to be much published on the species’ natural history or diet preferences.

Many thanks to Ross Hill (Meford, Oregon) for identification, and to Edward Mockford (University of Illinois) for helpful references on the species.

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