An extraction method for rapid counts of insect eggs and small organisms.
The following is based partly on the author's abstract. Insect eggs and small organisms can be removed from foliage and bark by means of solvents and recovered on filter paper. In tests in British Columbia, acids, xylene, turpentine, isopropyl alcohol, ethanol, detergents, acetone and potassium hydroxide were used to remove the eggs of Epinotia sp. from pine needles, but only the last two were successful. In a test in which sodium hydroxide was used to remove eggs of Adens variaría (Fern.) from the foliage of western hemlock [Tsuga heterophylla], 96% of a known number were recovered; in other tests, only 47-70% of the numbers of eggs recovered by means of the solvent were detected in direct counts, Tests indicated that the extraction method required one-third to one-tenth of the time needed for direct counting and was more consistent and less affected by differences in personnel and working conditions. The method and solvent must be selected and modified to suit the organism.