To assess the insecticidal effect of vapour originating from small quantities
of Lindane at a temperature of 25°C. (77° F.) twelve series of experiments were
conducted in which stored product insects in closed fumigation chambers were
subjected to the vapour from decreasing dosages of Lindane deposits (200-5 mg.
per cub. ft.). The correctly measured quantity of the insecticide evenly distributed
on surfaces of equal size was achieved by impregnating sheets of paper with a
Lindane solution of desired strengths. The following insect species were included
in the tests: - Triboleum confusum Duval, Sitophilus (Calandra) granaria L.,
Rhizopertha dominica F., Acheta bimaculata de G., Dermestes vulpinus F. larvae,
and Tineola bisselliella Hummel larvae.
The susceptibility of the different insect species varied considerably, but
vapour originating from 5 mg. Lindane in one cubic foot of air was sufficiently
toxic to produce a complete kill or high mortality after several days of exposure.
The period until death supervenes does not correspond with the dosage applied.
The mortality rate is dependent rather on the length of exposure.
This principle is recommended for long term protection of stored products
and for the control of insect pests in enclosed spaces.