Photo: White-lined Sphinx Moth, Judy Gallagher
Judy Gallagher is an ASNV board member and a regular surveyor of local wildlife who also captures photos of what she sees, in particular the less common species.
White-lined Sphinx Moth hovering while nectaring on a flower, Judy Gallagher
Sphinx Moths, also known as Hawk Moths, are a moth family whose members are known for their amazing flying ability. They have narrow wings and aerodynamically efficient abdomens, great adaptations for rapid flight. They can hover while nectaring on flowers, and some sphinx moths can fly at more than 10 miles per hour. There are over 1,400 world-wide species, of which more than 100 live in North America.
Pawpaw Sphinx caterpillar munching on Pawpaw, Judy Gallagher
Many Sphinx Moth caterpillars are host-specific, meaning that they only eat one plant or plants in one family. For instance, Pawpaw Sphinx caterpillars eat Pawpaw, Virginia Creeper Sphinx caterpillars eat Virginia Creeper, etc. Note the Sphinx-like pose, which is what gives this moth family its common name. The yellow thing at the bottom left of the caterpillar in the photograph is the old “skin” of the caterpillar, which has molted recently.
Almost anyone who has grown tomatoes knows about tobacco hornworms, huge caterpillars that can decimate tomato (and tobacco) foliage. These caterpillars are the larva of the Carolina Sphinx Moth, Manduca sexta. They are called hornworms because they have a horn-like protuberance on their rear end. One could be forgiven for wondering why these destructive organisms exist, but they have some helpful uses. Hornworms often are bred in captivity. Some are used as an artificial diet for captive reptiles, and in captivity the hornworms are fed on plants that do not contain toxins. So, a wild reptile might not be able to eat a caterpillar because it has accumulated toxins from a plant, but it could eat the same caterpillar species in captivity if the caterpillar was raised on non-toxic plants. Because of their large size, hornworms also are used as animal models for testing medical imaging.
Adult moths mostly feed on nectar, although a couple of tropical species feed on eye secretions, and one species feeds on bee honey.
Gaudy Sphinx caterpillar, pretending to be a snake Judy Gallagher
Caterpillars have interesting defenses against predation. The Tomato Hornworm sequesters toxins from the tomato plant, which makes it unappetizing to birds. The Gaudy Sphinx caterpillar, which you'd be more likely to see in Florida than here, looks more like a snake than a caterpillar. Walnut Sphinx and Nessus Sphinx caterpillars make weird hissing noises to repel predators. Caterpillars sometimes regurgitate sticky substances on ants and parasitoids to fight them off.
Catalpa Sphinx caterpillar with wasp cocoons, Judy Gallagher
But there are some predators that are hard for a caterpillar to escape. Parasitic wasps and flies lay eggs on caterpillars, and the caterpillar serves as live food for the wasp or fly larvae. The caterpillar ultimately dies. Some parasitic wasp species only parasitize one moth species. That leads to an interesting balancing act, as the wasp obviously wants food for its young, but if it lays eggs on all available caterpillars, then the parasite also would die out because there would be no more caterpillars for the wasps to parasitize.
Snowberry Clearwing Moth rolling up its proboscis , Judy Gallagher
While many sphinx moth caterpillars are destructive, the adults are important pollinators. They aren't as good pollinators as bees, who deliberately collect pollen, but sphinx moths pick up and transport pollen on their long proboscises or tongues. When not in use, the proboscis rolls up. Sphinx moths have the longest tongues in the moth and butterfly world. They like tubular flowers that are not easily pollinated by other insects. And most sphinx moths are nocturnal, so they feed from and pollinate flowers that are not visited by bees and other day-flying pollinators.
Pawpaw Sphinx, not blending in well against the white background, but imagine how hard it would be to see against bark, Judy Gallagher
Adult moths also have some defenses against predation. The Snowberry and Hummingbird Clearwings, both day-flying moths, look a bit like a large bee or a small hummingbird. Many sphinx moth adults are drab or cryptic looking to avoid detection. Some tropical sphinx moths make sounds by rubbing their genitals against their abdomens to confuse bats.
Small-eyed Sphinx, Judy Gallagher
Even cryptic moths can be beautiful. From a distance, it looks drab and unexciting. But take a closer look at the Small-eyed Sphinx. It has a pleasing shape, and the colors are extraordinary.
So please plant night-blooming flowers, especially flowers with long tubes, so you can enjoy these wonderful moths in your garden.
View more of Judy’s Observations from Meadowood articles here.