Greetings, BugFans,
The BugLady has mentioned before that she has several “nemesis bugs” – insects whose photographs are inevitably out of focus. Fireflies, for some reason, are one of those groups. So, when she saw this small (1/3”) beetle on a leaf in a bog at the start of August, “here we go again” flitted through her brain briefly. Then she looked at the camera monitor and thought, “Hmmmm – kind of lumpy-looking for a firefly.” And it wasn’t a firefly, though it’s considered a firefly mimic, cashing in on predators’ respect for the firefly’s chemical defense system.
And it’s fun to find an insect she’s never seen before. Unfortunately, this one is pretty good at flying under the radar.
It’s in the Metallic wood-boring beetle family Buprestidae, which we have visited before and which has some pretty spiffy members (hence their other common name, Jewel beetle) – Chrysophana conicola – BugGuide.Net,
?Metallic Wood Boring Beetle? – Buprestis salisburyensis – BugGuide.Net,
Mastogenius castlei Champlain & Knull – Mastogenius castlei – BugGuide.Net
and Metallic Wood Boring Beetle – Buprestis aurulenta – BugGuide.Net. It’s a big family (more than 15,000 species), whose larvae are collectively known as Flatheaded borers, which tells you what they do for a living. Like the Long-horned beetles, Cerambycidae, who have fans because of their improbable antennae, Buprestids have fans because of the flashy elytra (wing covers) of some species, which, alas, puts them in the crosshairs of collectors and vendors.
The ALDER GALL BUPRESTID (Eupristocerus cogitans) aka the Pondering jewel beetle (and, in French-speaking Canada, “Bupreste pensif”) is a taxonomic and geographic outlier – it’s the only species in its genus (a monotypic genus), and it’s also the only Buprestid in its Tribe, Coraebini, that’s found in North America (most of the rest live in Asia and Africa). The BugLady couldn’t find out what it’s pondering.
Bugguide.net shows its range as the northeastern quadrant of North America, south to Virginia (and including Wisconsin and Michigan), but other sources list it as far south as Florida and as far west as Texas. It occurs in wetlands where its host plants grow.
Here’s a glamour shot – Beetle ID – Eupristocerus cogitans – BugGuide.Net.
Gall-making is seen in a variety of insects, but the most common gall makers are flies and wasps, plus some kinds of mites (spider and tick relatives). Beetles, not-so-much. Buprestid beetles – hardly ever. Of course, many beetle larvae chew on plant parts and their chewing may result in a reaction by the plant’s tissues, but characterizing that reaction as gall-vs-not-a-gall depends on whose yardstick you use. Larvae of the Alder gall buprestid tunnel into the stems of living alders and river birch and make galls there. One source said that they can cause damage to wood, but one-one else seems to be getting too excited about that.
Of course, it’s hard to find a larva that makes its home in plant tissue so you can study it. In a paper about two new gall-making Burestids in South Africa, C.H. Bellamy and C. S. Scholtz wrote, “Gall formation in plants induced by the activity of buprestid larvae is a rarely-recorded phenomenon.” And they go on to say that “The overall lack of knowledge concerning buprestid larvae and their interaction with host plant species will hopefully, in time, be corrected and will undoubtedly show that many more species of Buprestidae are involved in gall formation.”
The adults are preyed on by the wonderfully-named Smoky-winged beetle bandit (Cerceris fumipennis), a small, solitary, ground-nesting, square-headed wasp Wasp with stripe on abdomen – Cerceris fumipennis – BugGuide.Net. Smoky-winged beetle bandits make beetle collections to cache in the egg chambers of their eventual young, and they target many tree-feeding beetles, including the Alder Gall Buprestid and also the infamous Emerald ash borer (another Buprestid).
Grammar alert – the Beatle bandit is spelled (by entomologists, who are loath to depart from traditional spellings) “Smoky-winged,” but the Google spell-check is unhappy with that, so the BugLady Googled “smoky vs smokey.” Turns out that “smoky” is the original spelling, but at any rate, “smoky tends to be an adjective, and smokey tends to be a noun. Act accordingly.
The BugLady