Bugs abound at summer's end




Colorado's summer is drawing to a close. But the season’s remaining dog days still hum with the coda of hungry insects rushing to fill up before the coming fall.  The other weekend, I happened upon one such bug, the pleasing fungus beetle (Gibbifer californicus), as it searched the hilly forests south of Denver for a feast of fungus.

The inch-long beetle is hard to miss: its elytra -- the insect's hard, protective forewings -- are an uncompromising shade of bridesmaid's dress-blue and are pitted in dark black spots --  as if the indentations were made with a tiny, ink-tipped pin.  The beetle ranges throughout the Southwest and is common in Colorado, especially after heavy rains.  They are found in aspen and pine forests where they feed on fungi that have colonized logs and trunks.

Pleasing fungus beetle larvae are worm-like and resemble bluish miniatures of the “graboid” monsters from the cult sci-fi movie Tremors. When larvae transform into pupae, the beetle’s final life-stage before adulthood, they often gather together beneath logs to molt in large groups. The result is a graveyard of shed skins, hanging upside-down like a dessicated colony of tiny, chitinous bats. 

Another western bug that's making the most of the summer's flagging

bounty, is the Chonchuela stink bug (Chlorochroa ligata), a striking though pestiferous insect classified in the true bug order, Hemiptera. 

Like most stink bugs, Chonchuela bugs feed on plant juices, which they suck up using piercing, syringe-like mouth parts. They are particularly fond of mesquite, balsam-gourd, and agarita. 

Chonchuela are very sociable at mealtimes. They shun the kids' table and feed, instead, in large groups that include adults, hatchlings and nymphs of all ages. Lunchtime crowds can be so large that the bugs cause serious economic damage to western tomato, corn, and alfalfa crops.

In the northern parts of their range (which extends to Canada), the bugs are a  limey shade of green. But in Colorado and much of the Southwest, Chonchuela bugs are black with a nearly fluorescent red-orange rim; a color-scheme that brings to mind a pair of bug-sized Pasodoble dancers, squaring off in the greenery.

Marian Lyman Kirst is an intern for High Country News

Image of hanging bug skins courtesy Rich Hover, Senior Leader for WINGS.

All other photos by Marian Lyman Kirst