A Method for the Topical Application of Small Measured Doses of Insecticide Solutions to Individual Insects

Abstract

A microburette made from glass capillary tubing is mounted on the mechanical stage of a microscope and filled with insecticide solution to a point at which the meniscus is in the field of the microscope. The magnified images of the meniscus and a calibrated micrometer scale in the eyepiece are projected on to a small screen mounted close to the tip of the microburette so that the scale and the insect being dosed can be seen simultaneously. This feature renders the apparatus particularly suitable for topical application work in which accurate positioning of the dose on the insect is required. When an insect, held in a suction device described, is applied to the tip of the burette, the solution flows out unaided, and stops immediately the insect is removed. With the microburette described, doses from 0.005 to 0.035 μl. can be dispensed to within ±0.00035 μl. The apparatus can be made to cover several other dosage ranges, either lower or higher, by simple modifications which are discussed.