This olfactometer differs from previous models in the materials used in construction and in technical modifications. Plastic tubing and lucite panels were used whenever possible. Two lucite cylinders connected by a small doorway form the insect test cage. This improvement makes the cage equal in size and shape to the influent ports, thus eliminating dead air spaces and the intermixing of the airflow between the alternative compartments Other improvements include accessibility of all the control mechanisms, modified influent ports, a double 3-way valve mechanism for shunting the airflow from one alternative compartment to the other, and the incorporation of hygrothermographic equipment onto a removable platform beneath the test cage.