L-Lactic acid: a mosquito attractant isolated from humans.

L-Lactic acid was the major component in material isolated from humans that was active as an attractant for female yellow fever mosquitoes, Aedes aegypti (L.). The L(+)-isomer was several times as attractive as the D-isomer. Good correlation was found between the attractiveness of an individual to mosquitoes and the quantity of lactic acid present in an acetone washing of his hand.