Finding Four Grape-feeding Sphinx Species for the First Time!

We found four sphinx species that specialize on Vitaceae for the first time today: Nessus sphinx (Amphion floridensis), lettered sphinx (Diadema inscriptum), Abbott's sphinx (Sphecodina abbottii), and the Virginia creeper sphinx (Darapsa myron).

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Ever since we moved from California to Ithaca last fall, one of the first things we noticed about the landscape was the ridiculous abundance of wild growing grape (Vitis sp.) and Virginia creeper vines (Parthenocissus quinquefolia), something unique about the Eastern United States.  We knew at once that the following summer we should go looking for sphinx species that specialize on this vines (Vitaceae), since, frankly, there are a ton of them here - five to be exact. Namely, they are the Nessus sphinx (Amphion floridensis), lettered sphinx (Diadema inscriptum), Abbott's sphinx (Sphecodina abbottii), Virginia creeper sphinx (Darapsa myron), and Pandora sphinx (Eumorpha pandora). All are of the Macroglossinae subfamily of Sphingidae, a group with a large number of Vitaceae specializing species.

Ever since the weather got warm in May, we've been keeping a good eye on all the Vitaceae vines around here for a chance to find the larvae or eggs of one of these species. We weren't having much luck and were starting to give up hope lately, especially since the vines are so common that it makes it very difficult to check them all (eggs/larvae become "dilute" when the host is too abundant for a species). However, to our great surprise, today we didn't just find one, but four of the five sphinx species (all but Pandora, a late-season flier)! 

Nessus sphinx (Amphion floridensis):​
This was the first species we found. There were two second instars, both about the same size, at two different locations. One was on a large grape vine around the North Campus dorms and the other was on the creeper growing along a stone fence at the end of Beebe Lake adjacent to the Botanic Gardens (which was the locality we ended up finding all the other species as well). They are pale bluish green with two white stripes down the dorsal abdomen and a red and black horn. Overall a very ordinary, not very unique sphinx look, maybe because they are still in an early instar.

Lettered sphinx (Diadema inscriptum):
We found four eggs and a molting fourth instar on the same creeper vines near the Amphion floridensis larvae at Beebe. Three of four eggs were laid directly on the new shoot tips where they are very cryptic next to the flower buds. The other egg was on the underside of a very new leaf at the end of a shoot. The molting fourth instar was located on the underside of a leaf where a dozen or two frass pellets had accumulated. It is bright yellow green with two yellow stripes down the dorsal abdomen and a yellow horn. The thorax is also slightly enlarged like a number of other Macroglossinae larvae.

Abbott's sphinx (Sphecodina abbottii):
We found a molting third instar larva on the same creeper vines at Beebe. Like the Diadema inscriptum fourth instar, it was on the underside of a leaf where a dozen or two frass pellets had accumulated. It is by far the most unique looking larva of the four, perhaps one of the most unique sphinx larvae we have ever seen. It has a long body that can curl into a circle when disturbed.  It is pale green and covered completely in a white, powdery substance similar to the powder that accumulates on some Attacini silkmoth larvae (Callosamia, Samia, etc.). Unlike most sphinx, it has a large yellow knob like tubercle in place of a horn. It is quite large for a third instar larva and will likely be the largest of the four species we found today.

Virginia creeper sphinx (Darapsa myron):
This was the last species we found after we walked down the road to the creeper at the entrance of the Botanic Garden. We found three eggs, two fresh and one partially developer. The two fresh ones were laid together on a leaf, and were a translucent pale green. The partially developed one was laid singularly and was red and yellow. All eggs were laid around the tips on the undersides of leaves near the periphery of the vine shoots (but not the unhardened new growth).

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​Alan Liang​
​Alan Liang is a student at Cornell University in Ithaca, New York pursuing an undergraduate degree in entomology. He is co-owner and a main contributor of the Liang Insects blog and photographs.

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