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Photo by Drew Albert |
Drew Albert of our Master Naturalist chapter found this beauty
hanging out in a tower of the National Weather Service where he works.
This was a restricted area and it wasn't wearing an ID, but he turned a
blind eye and a camera onto the trespasser.
This is a Pandora or Pandorus sphinx moth,
Eumorpha pandorus. It
seems appropriate that it was hanging out at the airport as it
resembles a stealth bomber that is painted in jungle camo, like Mother
Nature had been watching too many Rambo movies that day. They fly predominately at dusk on green to brown wings that can span 4.5 inches. Their wing shape looks a lot like the somewhat smaller hog sphinx moth.
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Hog sphinx, Darapsa myron - Chris Barnhart |
The larvae are just as impressive as the adult. They grow up to 4 inches long by feeding on grape species (
Vitis) as well as Virginia creeper. There is considerable variation in the colors of their various instars. The last instar climbs down to the ground and burrows into the loose soil. There it will pupate in the fall, forming the cocoon that will be its home until it emerges next year as a beautiful moth.
The caterpillars will go through five molts, called instars. Early instars have a horn like most sphinx moths, for example the familiar tomato horn worm. Unlike their cousins, the Pandora's horn has a cute little curl. This disappears in the fourth instar, replaced by a little eye mark.
Like many other caterpillars, their prolegs have special hooks which allow them to feed upside down, clinging to the underside of a leaf to hide from predators. At times they will tuck their two front segments into the third, giving the otherwise some what pointed head a blunt appearance. When they are threatened they use a vulture-like defense, vomiting up a sticky substance.
It doesn't always turn out well for
caterpillars. In addition to their contributions to the food chain for
birds, insects and even snakes, there are various parasites that utilize
them as a nursery for their young. The specimen above is still alive,
but just barely. It was infested by the eggs of a parasitic wasp whose
young have just pupated and emerged. The parasites preserve all the
caterpillar's vital functions until the last minute to maintain their food source.
You can see a little wasp at the bottom, presumably newly emerged from
the pupa.
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The late Jan Stiefel had submitted 779 photographs to Bugguide.net and over 129 Door County, Wisconsin moth
records, which are documented with the state. She had served as editor
of the "Wisconsin Entomological Society Newsletter"
since 1999.
There is more information at the uwm.edu/ website.