Pollinator or Pest? Meet the Five-Spotted Hawk Moth

beneficial insects Pollinator or Pest? Meet the Five-Spotted Hawk Moth

by Morgan Greene

Summer is upon us, and so are the sphinx moths. Also known as hawk moths or hummingbird moths, these occasionally diurnal insects are a common sight in New Hanover County from late spring to early fall.¹ From the mottled browns and grays of the Rustic Sphinx to the geometrically striped wings of the Banded Sphinx, these large moths come in a variety of colors ranging from humble to mesmerizing and sport patterns that provide excellent camouflage or dazzle passersby.

Unfortunately, not all sphinx moths in the Wilmington area garner praise. Tomato hornworms, larvae of the Five-Spotted Hawk Moth, and the similar tobacco hornworms are notorious pests of tomatoes and other nightshade plants. These large green caterpillars are voracious eaters that typically consume the leaves of their host plants, often beginning at the top of the plant and working their way down.² Spotting dark droppings on your tomato leaves is a tell-tale sign you’ve got tomato hornworms on your hands.

If you do spot these hungry caterpillars in your garden, fear not—these pesky larvae aren’t as terrible as they may appear and can actually benefit your garden community! Beneficial insects like green lacewings prey on tomato hornworms, and the caterpillars sometimes fall victim to parasitic wasps that lay their eggs on the caterpillars’ backs. Adult hawk moths, on the other hand, are food for animals like bats and lizards.²

Five-Spotted Hawk Moths are also important nighttime pollinators that drink the nectar of honeysuckle, phlox, petunias and other flowering plants.³ If you still decide you’d rather not have tomato hornworms in your garden, the caterpillars are harmless and can easily be relocated by hand, so there’s no need to use potentially harmful pesticides. Plants like dill and basil have also been shown to deter Five-Spotted Hawk Moths from laying their eggs nearby.²

Even though tomato and tobacco hornworms can be a nuisance, most sphinx moths and their offspring are much more beneficial than harmful to gardens and other local ecosystems.⁴ To spot a FiveSpotted Hawk Moth in action, your best bet is to search at dusk when the moths are most active. The moths have a row of five or six orange spots on either side of their abdomen and can have wingspans over five inches long, but their mottled light brown and white coloration makes them difficult to find amongst the trees. In flight, these moths can easily be mistaken for hummingbirds thanks to their size, shape, agility and hovering ability.⁵

Whether you regard them as beautiful pollinators or tomato-munching pests, one thing is for certain: just as spring is for the butterflies, in New Hanover County, summer nights belong to the sphinx moths.

Five-spotted Hawk Moth (Manduca quinquemaculatus) caterpillars are easy to relocate by hand if you would rather not have them in your garden. Observation © tomatoshepherdess, www.inaturalist.org/observations/115567277. No changes made. The Five-spotted Hawk Moth (Manduca quinquemaculatus) is an important nighttime pollinator. Observation © Kai Joaquin, https://www.inaturalist.org/observations/111739053. No changes made.

Sources

1 Moths of North Carolina (ncparks.gov) bit.ly/3OY2lIL 2 Tomato Hornworms: How to Get Rid of

Tomato Hornworms | The Old Farmer’s

Almanac bit.ly/3R7VpKX 3 Five-spotted Hawk Moth (insectidentification.org) bit.ly/3Icd0NA 4 Sphinx Moths (Hawk Moths | Missouri

Department of Conservation) bit.ly/3yGJRXG 5 Tomato hornworm, Manduca quinquemaculata (Haworth) (ufl.edu) bit.ly/3uqLN4b Morgan Greene is a senior at UNCW majoring in biology with a concentration in freshwater and terrestrial conservation. She enjoys sharing fun facts about insects and other tiny animals on her blog, The ArthroBlogger, found at thearthroblogger.com.