A MECHANICAL METHOD OF MASS COLLECTING LEPIDOPTEROUS PUPAE AND PARASITE COCOONS FROM INFESTED SOIL

Extract

Many species of Lepidoptera, especially cutworms attacking forage, cereal, and oilseed crops, pupate in the soil. Most parasites leave their hosts after they enter the soil and so field collections are an excellent source of healthy pupae and parasite cocoons. Previous methods of obtaining adults involved collecting pupae by placing shovelfuls of soil on screens on a mechanical shaker and removing the exposed pupae. This was suitable for the harvesting of only a few dozen pupae as the capacity of the shaker was limited. A more efficient method of exposing them was required. We describe here a technique which we have used for large-scale collections.