Friday, July 19, 2013

One-eyed Abbott

I stumbled across this picture in my files yesterday, an unknown from 2010 that I had never identified.  Its dramatic single eyespot on the top of the head was distinctive but I couldn't find a match so I sent it off to Kevin Firth's same-day service.  Bingo!... Abbott's sphinx moth caterpillar.

The caterpillar of Abbott's sphinx, Sphecodina abbottii, changes its appearance dramatically  during its four instars (molts).  As you can see from the pictures below by Jo Ann Poe-McGavin, the first instar starts with a horn resembling a hypodermic needle.  The second instar loses the horn, converting it to an orange spot.

First instar- note horn

Later instar- horn replaced with orange knob

With the final instar before it forms its cocoon, things get really interesting.  The orange spot becomes a very convincing eyespot, complete with iris, pupil, and even the white reflecting spot in the middle.  To complicate things further, it can either be a brown color with 10 pairs of pale green saddles or come out in a tan wood-grain pattern like ours above.  If poked, it is said to squeak and bite at the attacker.
My wood grain version
Last instar, green version- Eddie Calloway

Abbott's sphinx moth- CircusCyaneus
The moth that emerges from the cocoon is no slouch either.  Its scalloped wings and coloration blend right in with tree bark and it adds to the effect by raising its abdomen at rest, resembling a broken twig.

Thanks to Jo Ann Poe-McGavin who makes all her pictures available for our common use.  She has submitted more than 3,000 pictures to Bugguide. 

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