Eumorpha fasciatus

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SphinxMothLarva.jpg

Eumorpha fasciatus on Mikania scandens, central Florida

11 Comments

The banded sphinx moth Eumorpha fasciatus is a member of the widespread sphingidae family, also known as hawk moths or sphinx moths. This species ranges from Argentina to Canada. Hawk moths are important pollinators of many plants.

Thermoregulation

Large flying insects need a lot of power to sustain their rapid wing movements. In cold weather they may have to shiver to warm up enough to fly. They often operate their flight muscles at your body temperature or even warmer. In warm air their flight muscles may generate too much heat. Excess heat can be shunted from the insulated thorax to the abdomen for dispersal. The heaviest sphinx moths and bumblebees approach the smallest humming birds in size and energetics. Humming birds let themselves cool down and enter torpor when resting at night, then accelerate their metabolism to warm up for flight in the morning.

Very nice image of Eumorpha fasciatus. This is the first time I have read of them feeding on Mikania scandens. Usually they feed on members of the Onagraceae family. Sightings in Canada are extremely rare and probably occur in the fall. They are likely wind assisted strays. Visit http://www.silkmoths.bizland.com/FLsphinx.htm for Florida Sphingidae.

Bill Oehlke

Thanks for that Florida link Bill. I didn’t realize we had so many sphingid species in the state. I haven’t run across them. Are both larvae and adults mainly active at twilight?

Getting back to Eumorpha fasciatus, it was definitely on Michania scandens but that’s a scrambling vine that was mixed with other plants. I didn’t watch long enough to see exactly what it ate. By the way, the species has a very large range. How far do adults usually travel, if you happen to know?

Larvae, especially when they become voracious consumers in the final instar, are active day and night. The adults feed on flower nectar primarily at dusk and through the night. There are some Sphingidae species in Florida that feed during the day, but most feed in the evening or at night. The moths are also attracted to lights, and some people collect them that way. I often am asked to identify larvae of various Sphingidae species. The images that I receive of Eumorpha fasciatus are often of larvae found around ponds or lakes, roadside ditches or water ways where larval hosts (primrose-willow, Ludwigia (water primrose) and other plants in the evening primrose family) are found. I am also often asked about how one could care for the larvae and witness the transformation into the moth stage. Hence I posted an article at http://www.silkmoths.bizland.com/Ma[…]st2008tw.htm The same procedure will work for most Sphingidae species.

As a kid I gathered a species of theses things by the pound for fish bait. Having a good catalpa tree around made bait easy to gather.

I always wondered how the tree survived such massive infestations.

The Catalpa feeders would be Ceratomia catalpae, well known as excellent fish bait in the southern states.

To original post: It would be great if some of your friends can also contribute images. I would request, however, that you pass on to them my request for data with image submission: date, precise location, habitat (especially if they know nectar source or food plant).

Yes, I do like to create checklists at the county level as they weed out species that might be present elsewhere in the state, making it a bit easier for someone to do id work. Dates are remarkably consistent from year to year for a given location. Even elevation helps with some of the Saturniidae and Sphingidae species from South America where there are steep mountains. Some species fly to a certain elevation and then are replaced by a very similar species just a little higher up on the slopes.

I receive many images from all over the world. Last week I received some Saturniidae images from Gabon, one species that had been photographed last year in mid November was again photographed this year on the very same date. It’s also good for me to have multiple image with different views. Some species are easy to id, but it really helps with the tricky ones if I have lateral and dorsal images and shots of the head, feet and horn (Sphingidae).

I am amazed at the quality of images that arrive. Hundreds of people have sent me some very outstanding photos, such as yours, over the last decade.

In dry regions, the onset of the rainy season does trigger some eclosions, but in most areas photo period and temperature determine development rates. A cool spring can slow things down while a warm spring and hot summer can make time for an additional brood.

I always wondered how the tree survived such massive infestations.

Maybe its bark was worse than the bugs’ bites?

Sorry to quibble, but that doesn’t look anything like Mikania scandens, to me. This is the Climbing Hempvine, as I recognize it. I can’t offer a decent guess as to the correct plant, as cropped; is a wider view available?

Hi Chris, in this photograph, not taken for plant ID, the leaves are almost head-on. This messes with your perspective. Once you get past that, the leaves are lobed at the base as they should be, what you can see of the venation looks right, the stems have ridges as they should, older stems have turned dark purple as they should (see the other photo I will send to you) and the flowers although past their prime look right. It looks OK to me. The Florida plant Atlas has lots of images of both live plants and herbarium specimens.

Wow, Pete! After that other photo you sent, I’m convinced. The flowers, especially in the second image, seem dead-on. However, the key was that stem in the grasp of the Eumorpha’s legs in the second photo; that’s Mikania. Those leaves in the posted image look completely wrong; the flowers are right, and that stem in the grasp is right. Trick Photo!

What seems to bug me is that the vine is so young that the leaves don’t have their normal appearance, yet it’s mature enough to be flowering. It’s the “habit” of the leaves that appears so wrong. They are typically flaccid and pointed straight towards the ground. Also, without having access to my keys, I would have guessed they should be hirsute, whereas the depicted leaves appear glaucous. However, I’m in a friend’s carport watching football, so I will merely bow and admit to your better plant-fu.

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This page contains a single entry by Pete Dunkelberg published on December 29, 2008 12:00 PM.

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