Here’s a nice insect with a dinosaur look to it. This is the Wheel Bug,
Arilus cristatus, the largest of our local assassin bugs. It’s a predator that stalks the plants looking for insect prey. It prefers to prey on soft bodied insects, but I’ve seen it tackle a wide range of prey items.
The common name comes from this raised area of the thorax that resembles a cogged wheel.
The Wheel Bug is a true bug as evidenced by that tube shaped beak folded beneath the head. Insect prey is held by the strong forelegs while that beak is used to suck the prey dry. Although not normally aggressive to humans, the bug will bite if picked up and tightly held. The bite can be quite painful and result in a burning sensation that lasts for several minutes.
These bugs like to prowl about on flower heads where they’re likely to capture butterflies, bees and flies. They’re also good at zeroing in on areas containing leaf eating larvae.
The Wheel Bug’s flower to flower hunting technique makes it a fairly effective pollinator. The hairy legs have turned yellow from their pollen load.
I was working near the barn when a Wheel Bug landed on my shirt. I brushed it off onto a nearby picnic table and went back to work. It took wing from table and again landed on my shirt. I brushed it off. When it returned for a third time, I decided it just wanted to have its picture taken. Wheel Bugs are one of the group of assassin bugs and when an assassin bug demands your attention, you had better give it.
That beak folded back beneath the narrow head is used to suck the juices out of the bug’s insect prey. The bite of the Wheel Bug releases a toxin into the body of the prey that quickly paralyzes and kills. This toxin is what causes the severe reaction in humans bitten by the bug. The bite can take several weeks to heal, so it’s a good idea to be careful in your interactions with this creature.
The Wheel Bug is very alert and aware of nearby activity. I’m not sure of the function of the thoracic ornamentation. That spiked crest certainly makes it easy to identify this particular species.
The full wide abdomen suggests this is a female. Wheel Bugs overwinter as eggs, so this lady had better get busy with the egg laying. The holes along her side are called spiracles, sort of the insect equivalent of nostrils. The spiracles connect to tubes within the body that are used for oxygen and other gas exchange.
I think the most amazing feature of this insect is the elytral membrane, a portion of the wing that I call the thumbnail. The sunlight makes it glow an amazing gold or copper color. The flared abdominal segments bracketing the golden oval makes me think of an Egyptian artifact.
