Sunday, July 3, 2011

Five Inch Insect* Spotted & Photopraphed

Whenever I spend time outside after the sunset, I often turn on my outdoor floodlight. And like clockwork, it attracts all kinds of common night insects.

However, last night while grilling pork neckbones and hot Italian sausage, I noticed something a little more unusual -- a huge, long, large-winged insect (with a mantis-like head) resting at the corner of my back garage door:
View as seen from a few feet away
Apparently attracted by my bright outdoor floodlight, I estimated this creature to be about 5 inches long from the tips of its pincers to the end of its wings.

I knew this was a great photo opportunity and a good excuse to write another blog entry, so I grabbed my camera and snapped away.

While the top image was taken from a few feet away, the second snapshot was taken closer in macro mode with a full body view:
Full body view from top. 5 inches from tip of antennae to end of wing
The last image below is a close up of the head region. I wanted to get even closer but could not due to its large protruding antennas:
This is a male Dobsonfly. Males have elongated pincers (front)
So what was this beast of the night? Upon awakening this morning, I googled my way to an answer within about 10 minutes.

Dobsonfly ("The King Bug")

This is indeed a dobsonfly, or more specifically the male eastern dobsonfly - perhaps the most well-known of the 220+ species.

First & foremost, the good news for gardeners - they are not considered pests.

Dobsonfly's are nocturnal aquatic insects, living their short above-ground lives near ponds, lakes, rivers or in my case - streams.

Their first few years are spent living in the water as larvae, called hellgrammites. Anglers frequently use them as bait.

Eventually, they emerge from water to pupate & stay in a cocoon over the winter.

Finally from late spring to mid-summer, adult dobsonflys emerge and live only about one week, with a primary purpose of mating.

Though not venomous both male & female have sharp mandibles. While the male's mandibles are too large to gain enough leverage to pierce human skin, the females smaller mandibles may inflict a painful bite capable of drawing blood.
When threatened, dobsonfly's will raise their head and attempt to scare away danger by spreading their jaws, and if necessary, emit a foul odor from their anal gland.

OK, that's your insect lesson for the day. Next time you spot one of these, you can impress someone by identifying it on the spot. See, aren't you glad you learned something new this weekend?

*NOTE: Though the dobsonfly measures about 5 inches from tip of antennae to end of its wings, their actually body is only a few inches long.

Further research:
Tree of Life Web Project


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