Hornworm caterpillar

Week 3rd to 9th June 2013

This week’s Mystery creature certainly got a lot of discussion; not surprised as it was a tricky one; a lot of species look very similar!

To put you all out of your misery … it was a HORNWORM CATERPILLAR! (more specifically the TOBACCO HORNWORM).

photo credit: CameliaTWU via photopin cc

…and the adult moth is the SPOTTED HAWK MOTH  (Manduca sexta), also known as the SPHINX MOTH.

The adult moth (image source: wiki commons)

This species is very common in America (and probably only present in Ireland as imports).  Horworm caterpillars can grow up to three inches in length.  The tobacco hornworm is often confused with the tomato hornworm (Manduca quinquemaculata) as both look very similar and can each feed on similar plants.  The tobacco hornworm has white stripes along it’s body and a red “horn” while the tomato hornworm has V-shaped markings and a black “horn”.

Horworm eggs are typically laid on the underside of leaves.  When the caterpillar emerge they will eat through a large amount of leaves for a month or so before pupating in the soil, building a small hole a few inches below the surface.  The adult moths, commonly known as shinx, hawk or “hummingbird” moths emerge from the ground and feed on nectar.  The life cycle can be competed in 30 to 50 days and under the right temperatures, there can be two hatches in one Summer.


Science blogger and writer; Owner of Dr. How's Science Wows; Mother of three junior scientists who have taught me that to be a great scientist you need to look at life through the eyes of a child!