Seed Treatments for Wireworm Control with Particular Reference to the Use of Lindane1

Abstract

That control of wireworms appears possible by means of treating certain vegetable and field crop seeds with lindane prior to planting is shown by laboratory and field tests. Application as liquids gave good adherence and evenness of distr. of the chemical on the seed, greater safety to the operator, and equal or better insecticidal efficiency. The tolerances to different seeds varied markedly. Sugar beets, cotton, lettuce, and tomato were tolerant; cucumbers, cantaloupes, corn, peas, okra, milo, and barley were moderately tolerant; but beans, particularly certain large lima types, and wheat were susceptible to injury. Recommended dosages for this reason varied from 1% of a 25% lindane on sugar beets (of wt. of seed) to 0.0625-0.125% for large lima beans. Injury from greater dosages included delay in germination, stunting of the plants, non-absorption of the cotyledons in certain bean vars., reduction in seedling wt., or actual death. Insecticidal effectiveness was determined in the laboratory by confining wire-worms in salve cans with treated seed and checking mortality up to a period of 10 weeks. Lindane remained effective in killing wireworms on old sugar beet seed balls in the field for 2-4 mos. The gamma isomer was found to be the most effective component of benzene hexachloride, and the technical grade was more effective in killing wireworms than lindane, but also exhibited greater phytotoxicity. Aeolus sp. was most susceptible to lindane, followed In order of their decreasing susceptibility by Limonius canus L. calif ornicus. and an Anchastus sp. Insecticide-fungicide combinations controlled wireworms, seed-borne fungi, or pre-emergence damping-off organisms, Lindane was satisfactorily combined with Arasan, Semesan, Spergon, Ceresan M, Phygon, and yellow cuprous oxide. One seed treatment killed 50-93% of the wireworms in the seed row area, and reduced the total population of larger wireworms by approx. 50%. Lindane as a seed treatment was found to kill primarily by contact action.