Predatory beetles

As I was taking an early evening walk around the garden yesterday, a sudden flurry of movement drew my eye down to the mulch.  I poked around and uncovered a beautifully camouflaged little insect.  It was a rove beetle, probably Platydracus maculosus, the first I have seen in the garden.

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rove beetle (Platydracus maculosus?)

Rove beetles are predatory beetles with a very unbeetle-like appearance.  They have short elytra (wing cases) which leave the abdomen exposed.  Some species (there are about 63,000 species total) will curve the long abdomen when threatened, giving the appearance of a scorpion.

While Platydracus maculosus may be beautifully camouflaged, it isn’t the most beautiful predatory beetle that I have seen in my garden.  That accolade belongs to Calosoma scrutator, the fiery searcher.

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fiery searcher (Calosoma scrutator)

C. scrutator is one of the largest ground beetles in North America, and its alternative common name, caterpillar hunter, tells you all you need to know about its preferred prey.

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Smaller and more common than C. scrutator, but equally fierce, is Cicindela sexguttata, the six-spotted tiger beetle.

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six-spotted tiger beetle (Cicindela sexguttata)

I often see these little beetles patrolling sunny paths in the garden or our concrete driveway.  When approached, they usually fly a short distance, looking rather like a shiny green wasp, before landing and running rapidly away.  As a child, I learned the hard way that tiger beetles can bite hard.  If you must catch one to show your friends, put it in a jar.  Don’t hold it cupped in your hand.

The strangest of our resident predatory beetles, stranger even than a rove beetle, is the railroad worm (Phengodes species).  Males have large, feathery antennae and wings that extend beyond the elytra, making them look a bit like a fly or a moth, but it is the females, also called glow-worms, that are really weird.  The females are larviform (looking like a large larva) and have an elongated, segmented body lacking wings.  Each segment has a pair of bioluminescent spots, so in the dark the railroad worm resembles a train with glowing windows.

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female railroad worm (Phengodes species)

Railroad worms specialize in preying on millipedes, which they superficially resemble, and when disturbed they roll up, just like a millipede.

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Keep your eyes open.  Every time you go into a garden, there’s a chance you’ll see something you have never seen before.

Eyed elater

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This evening, as I was walking around the garden to see what I could see, I found one of my favorite North Carolina beetles.  This is Alaus oculatus, the eyed elater or eastern eyed click beetle.

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Click beetles are named for their defense mechanism:  a hinge in the thorax can be flexed rapidly,  propelling the insect high into the air with a loud click.  The smaller species are often quick to click, and it is always amusing to watch one jump and spin across the floor away from a bemused cat.

A. oculatus is the largest North American click beetle, and in my experience they rarely click unless seriously harassed.  When prodded, they seem to prefer folding in their legs and antennae to present a would-be predator with a hard carapace topped with those two threatening eye spots.  Perhaps the elongated body with disproportionately large “eyes” resembles the head of snake.

I sometimes stumble across the larvae of A. oculatus when investigating rotten logs for interesting fauna.  They are predators of other beetle grubs and look a bit like large flattened mealworms with menacing pincers.

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Caterpillars

Some recent sightings…

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Tobacco hornworm, the caterpillar of the Carolina sphinx moth (Manduca sexta)

Eldest offspring’s jalapeño plant was growing well and producing plenty of peppers until this big fellow showed up.  Hornworms feed on a wide variety of solanaceous plants, so I’m keeping a close eye on my Brugmansia and tomato plants.  On occasion, while prowling the garden at night with a headlamp, I have found adult moths visiting nocturnally fragrant Lilium formosanum and Crinum ‘Mrs. James Hendry’ flowers.

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Greater canna leaf roller, the caterpillar of the Brazilian skipper butterfly (Calpodes ethlius)

About a week ago, I noticed that something was cutting flaps in the leaves of my canna plants and stitching them shut with silk.  Peeling the flaps open revealed the caterpillars of the Brazilian skipper.  In late summer, my cannas are often infested with lesser canna leaf rollers (caterpillars of a nondescript moth, Geshna cannalis), but this is the first time I have seen greater leaf rollers.  Brazilian skippers are tropical butterflies that sometimes stray to the NC piedmont,usually in late summer.

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Fall webworms (Hyphantria cunea) eating sweetgum leaves

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Unlike the greater canna leaf rollers, fall webworms are a familar late summer sight in my garden.  They feed on a wide variety of hardwoods.  This year, they’re on sweetgum and possumhaw.  In previous years, I have found them on sourwood, black cherry, and American persimmon.

Mole cricket

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While driving down our lane, I noticed a large, dark insect scuttling across the dusty gravel.  It proved to be a mole cricket.  As a child, I used to catch mole crickets in our garden in southwestern Iran, but I haven’t seen one in decades.  This was like meeting an old friend.

There are several mole cricket species in the southeastern U.S., including some introduced species that are agricultural pests.  I think this may be the native Neocurtilla hexadactyla (northern mole cricket), but I let it go instead of collecting it for definitive identification.