After decades of study, BTI has been shown to affect almost exclusively black flies.

NPR: Waging a One-Woman War Against Black Flies

Ms. MALIK: People want the black flies controlled, and this is the best method.

NPR: Waging a One-Woman War Against Black Flies

Just when the snow is gone and the sun is warming things up, the black flies appear.

NPR: Waging a One-Woman War Against Black Flies

For 22 years, she has led a crew that takes it to black flies on their home turf.

NPR: Waging a One-Woman War Against Black Flies

Ms. MALIK: There's going to be black flies flying around, you know.

NPR: Waging a One-Woman War Against Black Flies

We arrived on the banks of the Comoue and the spot is idyllic - green, sunny, with the gentle noise of running water, basically the perfect breeding site for black flies.

BBC: Burkina Faso: Beating river blindness by fly-catching

He has rafted rivers in Yakutsk, dodged grizzly bears and black flies around Great Slave Lake (his record for fly bites is two hundred in a single night), and scouted rock formations on the Skeleton Coast, sometimes hiking more than twenty miles a day.

NEWYORKER: The Martian Chroniclers

Across quaking peat bogs and through clouds of black, biting flies, we hiked three miles into the backcountry of Newfoundland's austere northern peninsula.

FORBES: The World According to Yvon

One of those corny black-and-white forties Air Force films with tearful goodbyes as Jimmy Stewart flies off into the wild blue yonder.

NEWYORKER: Indianapolis (Highway 74)