Friday, August 1, 2014

Hornworms

Hornworm is a name given to the larvae of a group of species known as sphinx moths.  The name comes from the horn like projection found at the back end of the caterpillar.  I found this guy as I checked on the garden on my way to the woods.  This is the Tobacco Hornworm, perhaps my favorite of all caterpillars.  Some of my earliest recollections are of finding caterpillars like this stripping leaves from our garden tomato plants.  If undiscovered by parasite and predators, it is destined to become a Carolina Sphinx moth.


It pulls in its head and legs when disturbed and at a glance, looks very much like a natural part of the tomato plant.  When I was eight years old, I was the kid people called to remove these giant monstrosities from their tomato plants.  I was happy to oblige.  I don’t think they would have appreciated the fact that I took the caterpillars home and raised them to the adult moth stage.  Fortunately for me, we lived in an area where the species was double brooded, which meant that the early caterpillars that I collected transformed to adults without having to go through the winter.  I released the adults in our back yard and am sure they headed for the neighbors garden to lay more eggs.


As I entered the woods, I found a different species of hornworm.  This is the caterpillar of the Laurel Sphinx.  The colors are clear and bright when viewed close up.  At a distance, the caterpillar is almost impossible to see.  Green, yellow and black are the colors of a summer woods and this caterpillar blends right in.


I was especially impressed by the yellow bands around the legs looking like a brightly colored set of spats. 


What at first appeared to be a mottled pattern on the back, turned out to be wounds created by exiting Braconid Wasp larvae.  The caterpillar suffered massive internal injuries inflicted by the feeding wasp larvae and will not live long enough to pupate.


I found a third species of hornworm feeding in a thicket of Virginia Creeper.  This is the caterpillar of the Virginia Creeper Sphinx. 


There turned out to be several of the caterpillars in this patch of Creeper.  Most were hidden beneath the leaves, but this individual was on the move to a new feeding location.  All were this same pale green color which made them easy to spot against the darker green of the Virginia Creeper leaves.


The small head and forward segments ballooning into the large body is a characteristic of this species.  There are many more hornworm species I have yet to encounter, but I felt particularly fortunate to see three in one afternoon. 

4 comments:

  1. Excellent site - thanks to you, I was able to identify two Virginia Creeper sphinx caterpillars. Thanks!!

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  2. Hi, Kristin. I'm glad you found the post helpful. Hopefully you'll find some more interesting species of hornworms.

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