A small widely distributed bloodsucking insect of the genus Simulium. Black flies are also known as buffalo gnats from their humpbacked appearance. Female flies can inflict painful bites and constitute a serious pest to man at certain times of the year. S. damnosum in Africa and S. ochraceum in Central America and Venezuela transmit the parasites causing ‘onchocerciasis. S. venustum is a species common in North America.
A fly of the genus Simulium whose bites often cause local bleeding and pain.