Fig. 2.

Three-chamber in-line olfactometer. The olfactometer was constructed so that the vacuum pump drew air across the treatment and control cups and into the middle chamber, where 20 gravid females were introduced. Weigh boats containing test or control materials were placed on a small shelf at the end of each side chambers. Chambers were connected by 6 cm long (1 cm inner diameter) tubes extending 3 cm into both the side chamber and the central chamber