Goldsmith beetles are yellow or green in color with a metallic gold tint. Their bodies are shaped like eggs, and are big and heavy for a bug. They are about 20 to 26 mm long. Underneath, they have whitish woolly hairs. Their hardened front wings have rows of small holes. (Coin, 2005; Lockwood, 1868)
Goldsmith beetles live in the eastern, central, and southwestern United States. They also live in southeastern Canada. (Coin, 2005)
Goldsmith beetles live in forests with trees that lose their leaves, woodlands, and fields near woodlands. (Coin, 2005)
Like most beetles, goldsmith beetles transform from larvae to pupae to adults. The eggs hatch into grubs, which are whitish, C-shaped larvae. They can't move much, but they burrow to find a food source. They eat more as larvae than in other parts of their life. After 1 or 2 years, they enter the next stage of transformation, called pupae. Then, they transform again into adult beetles. (Libich, 2000; Williams, 2006)
Goldsmith beetles breed from April and July. The eggs grow inside the females for about 6 months, and then they lay them in clumps on top of the soil under a tree. They don't lay very many eggs compared to similar species. They stay as larvae for 1 to 2 years, and then become pupae. The adults come out from the pupa stage between May and July. (Breda, 2001; Coin, 2005; Lockwood, 1868; Williams, 2006)
Female goldsmith beetles lay their eggs on the soil near the roots of a tree or in rotting logs, because these are possible sources of food. Goldsmith beetles don't care for their young after the females lay the eggs. (Coin, 2005; Libich, 2000; Williams, 2006)
Goldsmith beetles live the first 1 to 2 years of their life underground as larvae while they develop. Larvae burrow through the soil around tree roots. They make large round burrows that allow them to move around a lot. While resting in burrows, they curl up on their side to protect their soft parts. Very young larvae can't move very much, but they can crawl on their bellies. As they get bigger, they can move forward by laying on their back and moving back and forth like a snake. After they become adults, they live life in the trees. They fly between trees eating. They are most active from twilight to dawn. In the daytime, they make themselves a little shaded tent of leaves that they hold together. At night, they fly around bright lights like at gas stations. Goldsmith beetles usually hibernate in the soil at about 38 cm deep. Larvae burrow down deeper in the ground. (Coin, 2005; Lockwood, 1868; McColloch, et al., 1928)
Like many of their close relatives, goldsmith beetles communicate by making noises with their legs. They move a ridged part of their body across thin ribs. They may use the sounds for mating or a different reason. In other similar beetles, these kind of sounds are used for courting, aggression, and defense. (Wessel, 2006)
Goldsmith beetle larvae eat tree roots and rotting logs. Adults eat leaves of willow, pear, hickory, oak, and poplar trees. Goldsmith beetles usually feed at night. (Lockwood, 1868; Milne and Milne, 1980)
Goldsmith beetles are eaten by birds that live in trees and eat insects. They are eaten by blue jays, yellow-billed cuckoos, and purple martins. Goldsmith beetles hide from predators in the tents they make to give them shade. This provides shade as well as cover from predators. Their bright gold color is probably a warning to predators, but scientists don't know if it's effective. (Judd, 1899; Lockwood, 1868)
Adult goldsmith beetles pull leaves from the trees where they live, which are usually willow and poplar trees. They are eaten by many birds that eat insects and live in trees. Goldsmith beetle larvae add air into the soil when they burrow and help dead logs decay. Goldsmith beetles and their close relatives get infected by sporeforming bacteria and milky disease bacteria. (Coin, 2005; Klein and Jackson, 1992; Lockwood, 1868; Williams, 2006)
Goldsmith beetles are possibly a nuisance to farmers and gardeners because they pull leaves from trees, but most of the time they live in trees. They are often confused with Japanese beetles, which can cause a lot of damage to soybean and corn crops. (Johnson, 1999)
Goldsmith beetles help their ecosystem by adding air into the soil and breaking down rotting logs.
Goldsmith beetles are uncommon, but they are not endangered or threatened. (Coin, 2005)
Goldsmith beetles are in the short story "The Gold Bug" by Edgar Allan Poe. (Breda, 2001)
Charles Park (author), Rutgers University, Asha Parmar (author), Rutgers University, Lauren Seyler (author), Rutgers University, Hetal Shah (author), Rutgers University, David V. Howe (editor), Rutgers University, Gail McCormick (editor), Animal Diversity Web Staff, Catherine Kent (editor), Special Projects.
Breda, J. 2001. "Cotalpa lanigera" (On-line). Accessed December 14, 2006 at http://entweb.clemson.edu/museum/beetles/local/btle28.htm.
Coin, P. 2005. "Species Cotalpa lanigera - Goldsmith Beetle" (On-line). BugGuide. Accessed December 09, 2006 at http://bugguide.net/node/view/4293.
Johnson, D. 1999. "Japanese Beetle in Soybean" (On-line). Accessed December 09, 2006 at http://www.uky.edu/Ag/kpn/kpn_99/pn990628.htm.
Judd, S. 1899. The Efficiency of Some Protective Adaptations in Securing Insects from Birds. The American Naturalist, 33(390): 461-484.
Klein, M., T. Jackson. 1992. Bacterial Diseases of Scarabs. Pp. 43-62 in T Glare, T Jackson, eds. Use of Pathogens in Scarab Pest Management. Hampshire: Intercept Limited.
Libich, T. 2000. "Beetles" (On-line). Accessed December 13, 2006 at http://www.goliathus.com/en/beetles.php.
Lockwood, S. 1868. The Goldsmith Beetle and its Habits. The American Naturalist, 2(4): 186-192.
McColloch, J., W. Hayes, H. Bryson. 1928. Hibernation of Certain Scarabaeids and their Tiphia Parasites. Ecology, 9(1): 34-42.
Milne, L., M. Milne. 1980. National Audubon Society Field Guide to Insects and Spiders. New York: Knopf.
Wessel, A. 2006. Stridulation in the Coleoptera - An Overview. Pp. 397-403 in S Drosopoulos, M Claridge, eds. Insect Sounds and Communication: Physiology, Behavior, Ecology and Evolution. Boca Raton: Taylor and Francis Group.
Williams, L. 2006. "Northeast Region Forest Pest Update - 06/14/06" (On-line pdf). Wisconsin Department of Natural Resources. Accessed December 09, 2006 at http://prodwbin99.dnr.state.wi.us/org/land/Forestry/Fh/PDF/NER-pestsupdate-2006-6-14.pdf.