Pretty but deadly: Flowers of doom

Tis the season of the mighty Asteraceae Family: asters, bonesets, goldenrods, sunflowers, etc. These harbingers of winter brighten the autumn meadows, and many a person remarks on fields painted bright with botanical gold, purple, and cream.

There is a deadly irony in the beauty of these wildflowers, however. Flowers are magnets for insect pollinators, and their presence is part of the charm of flower-watching. But for these nectar-seekers, the danger quotient ratchets up immensely when they alight on flowers. Predators are well aware that sooner or later potential victims will come to visit the flower patch, and they lay patiently in wait.

The robust creamy-white inflorescence of Tall Boneset, Eupatorium altissimum, is quite alluring to all manner of six-legged pollinators. If one of them chooses to work this plant, they had better watch their step. Look carefully and you'll notice three or four tiny bits of dead-looking flower.

Those brownish patches among the boneset flowers are anything but dead plant tissue - they are ambush bugs, a pollinator's worst nightmare. Here we have a Pennsylvania Leatherwing beetle cresting the dome of these flowers, and walking right into a trap. Look carefully: an artfully disguised ambush bug, Phymata pennsylvanica, lays in wait.

This beetle was lucky, or perhaps its size and armoring was just too much for the ambush bug. The latter made a stab at it, quite literally, but the beetle scuttled off intact.

Many bugs are not nearly so fortunate as that leatherwing beetle. I came across this scene two autumns ago. Spotting the little flower wasp from some distance, I stalked in for photos. No stalking was necessary. It had been captured and punctured by an ambush bug! These ferocious hemipterans lunge from the blossoms - an evil flower sprung to life! - and grab their victim with daunting raptorial forelegs. A quick jab with a syringelike proboscis injects chemicals which instantly disable the prey, and dinner is served.

Ambush bugs are common throughout Ohio and the Midwest, and with the exception of the previous wasp photo, I have made all of these images in the last week or so. These fascinating predators are not difficult to find, but obviously are easily overlooked. Their ability to match a flowery substrate is remarkable; the bugs are typically dappled with brown patches to mimic dead plant tissue. This ambush bug, another Phymata pennsylvanica, I believe, illustrates this perfectly as it tees up on a fading Gray Goldenrod, Solidao nemoralis.

Everyone should have a personal favorite ambush bug, and this is mine - the so-called Goldenrod Ambush Bug, Phymata americana (at least I think I am correct on these specific identifications; feel free to correct me if you know better). Goldenrod Ambush Bugs are a buttery yellow, and match the goldenrod flowers to an almost magical degree. An unsuspecting bee, fly, or skipper could be forgiven for not noticing it. The ambush bug will not be forgiving, however, and Dickinson might even have modified her lovely poem had she known that such horrorshows lurk within pretty flowers.

Seen well, an ambush bug is bizarre indeed. They remind me of little gargoyles. Utterly inscrutable, and without emotion. If one of these things was the size of a black bear, we would be in grave danger. Note the huge Popeye-like forelegs, there to seize and immobilize surprised victims.

Here's an ambush bug, prodded out of cover for our viewing pleasure. A more remarkable insect is hard to imagine. Next time you are among a goldenrod patch, or other plants that produce dense masses of blooms, investigate carefully for these beasts. I'm sure you'll find some.