Application of Larvacide (Mosquito Oil) by Use of Knapsack Sprayer

Miraflores, Canal Zone, June, 1910

Description: 11x 8 inches

Black and white photograph

One way of controlling the spread of malaria and yellow fever during the construction of the Panama Canal was the application of larvacide (carbolic acid, resin and caustic soda) in grassy areas to eliminate mosquito larvae. The application of larvacide was critical to Roosevelt’s efforts to complete the Canal by 1914.