Dung Beetles (Coleoptera, Scarabaeidae) and other Insects in Relation to Human Feces in a Hookworm area of Southern Georgia

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  • Department of Tropical Medicine and Public Health, Medical School of the Tulane University of Louisiana, New Orleans

Summary

Observations on human stools exposed in the field at Waycross, Georgia, in July, revealed that they may be buried by dung beetles within a few hours. “Tumble-bugs” (5 species), which form balls of feces and roll them away for burial at a distance, were most abundant and important as agents of removal, particularly during the day. Nine other species, which bury feces directly and produce mounds of disturbed soil at the site of stool deposition, were also significant, especially at night. Five additional coprophagous scarabaeids, of slight importance, were among a total of 74 collected species of insects attracted to human feces. The rest included 26 predatory Coleoptera, 19 Diptera, a few other coprophagous species (ants, cydnid bugs, earwigs, mole crickets), and a few parasitic wasps. The beetles collected in Georgia, Louisiana and Indiana augment the total reported from human feces in the United States to at least 91 Coleoptera, including 33 Scarabaeidae. Collections in feces-baited traps in Georgia also indicated that in seven days sufficient dung beetles were attracted every 24 hours in an area of about 0.2 acre to dispose of about 750 grams of feces, with two species of greatest potential importance. Differences in capacities and abundance of various species, influenced by region, season and local circumstances, would determine the amount and rate of feces-disposal at any particular place. Since feces are buried at varying depths (observed maximum, 9 inches) and carried away from the original site (20 feet or more), dung beetles may constitute an important factor in the epidemiology of hookworm and other enteric parasites of man.

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