February 5, 2012 11:15 am
I found this caterpillar feeding on a leaf of a dieffenbachia (common name dumb cane). It has a voracious appetite consuming almost a leaf approx 35cm x 19cm everyday for about 3-4 days. It has initially a bright green body with a head that resemble a small green snake. It is approx 8-9cm long and its body, the thickness of one’s pinkie (the last finger). The amount of calcium oxalate it consumes would have made it highly toxic to any small animals. From the size of each leaf it eats, it appears the equivalent of a man eating approx more than half a football field of poison and survive! How this little creature knows that it could eat this poison in such quantities and survive, and by doing so becomes a poison chalice for any predator making a meal out of it surely questions the evolution biologists’ premise that creatures like these evolve from some simple cells.
Would appreciate your help in identifying this wonderful creature. Location: urban house garden near the Inland Revenue House Singapore. Tropics.
Thank you for writing back to us after getting your automatic response that your letter was received. Out small staff does not have the ability to post every letter or even to respond to every submission. When we originally read your inquiry, we were unable to provide a quick identification without research, and then we never returned to your request. A second reminder is always helpful, but we greatly appreciate when readers attach the images again. We needed to go through our unanswered mail to try to locate your original submission. Our first thought was that this caterpillar had a head like a remora fish. Though its markings seem distinctive, we were unable to make out details because of the poor resolution of the photo. The fact that it had a caudal horn escaped our notice upon the first viewing. That single bit of information would have at least allowed us to provide you with the family name Sphingidae and that the common name of caterpillars from the family is Hornworms. We decided to do a web search of a few key words, and “caterpillar, Singapore, diffenbachia” immediately led us to the Common Butterflies of Singapore website and a match with the Hawkmoth Eupanacra elegantulus. The Common Butterflies of Singapore website states: “This hawkmoth is quite commonly found in urban gardens. The caterpillar host plants appear to be species from the aroid family like varieties of Dieffenbachia, Syngonium and Monstera deliciosa which are all commonly cultivated in Singapore gardens. The young caterpillars are slender, pale green with a straight pale pink spine at the end of their bodies.They have poorly developed false eyespots at this stage. They feed while on the underside of leaves to conceal themselves from predators. When they are not feeding the caterpillars rest near the base of the stems of the hostplant, blending in well as can be seen above.” Butterfly Pals has some wonderful photographs of the entire life cycle.