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Hummingbird Moths

FOR IMMEDIATE RELEASE
October 21, 2013

Small mysterious pollinators have been visiting late summer and fall blooming plants in our gardens in order to sip nectar. They beat their wings as fast as a humming bird but are smaller and stick their very long tongue out to gather nectar like a butterfly but remain hovering over the flower. In the fall months in Illinois, hummingbird moths a member of the sphinx moth species are numerous and come out close to dusk. There are 60 species of sphinx moths and the most common ones are the white-lined sphinx moth, clear winged sphinx moth, five spotted hawk moth and Carolina sphinx. The color of the white lined sphinx moth is mottled gray, brown and white with pink bands. The clear-winged sphinx moth is a large moth with clear wings that mimics a bee.

However cherished as adults, five spotted hawk moth and Carolina sphinx incite murderous rage in their larval stage to any gardener trying to grown tomato. The five spotted moth and Carolina sphinx also known as tomato hornworm and tobacco hornworm are large green caterpillars about 4 inches long and about as big around as a fat man's thumb. These caterpillars can demolish a tomato plant in as little as a few days. The first sign of them is the bare branches and stubs at the tips of the plants that have been stripped by these ferocious eaters. Although they are large they are just the right color to blend in. A small horn at the end of their abdomen distinguishes them from other caterpillars and provides a menacing fa├žade for any predators.

Four weeks after hatching from the egg, the hornworm begins its pupae stage by dropping to the ground to burrow. This time of year they will remain in the pupae stage throughout the winter. This is why it is necessary to clean up tomato debris and disc the soil in order to destroy the pupae stage.

There is no need to address hornworms with pesticides but instead pay the neighbor kid 50 cents a worm to pick them off the plants and feed them to chickens and birds. If you allow them to stay on the plant for a little time, nature will start to take care of the problem for you. Parasitic wasps will lay their eggs right on the bodies of the horn worms. The eggs will hatch and feed on the horn worm before they emerge from the white cocoons that decorate the horn worm. If you find a tomato hornworm parasitized by wasps leave it alone, it will stop feeding and die. New hatched wasps will seek other hornworms in the vicinity to lay their eggs.

Source: Kelly Allsup, Extension Educator, Horticulture, kallsup@uiuc.edu