Wire worm Behavior in Response to Chemical Seed Treatments12

Abstract

Orientation reactions of the wireworm, Melanotus communis, to various insecticide seed treatments were studied by following the movements of individual larvae tagged with radioactive cobalt in the soil. It was found that the repellency of certain insecticide seed treatments to wireworms apparently has two components (1) inhibition of the feeding reaction, and (2) orientation of the insects away from treated seeds. For convenience these are referred to as type one and type two repellency, respectively. Type two repellency does not preclude contact with treated seeds, and varies in degree depending on the insecticide used. Aldrin, dieldrin, endrin, heptachlor and lindane seed treatments all appeared to possess considerable type one repellency. Type two repellency was most pronounced with lindane-treated seeds, and with aldrin-treated seeds where this insecticide was not used in excess of 1 ounce of actual toxicant per bushel of seed. Dieldrin, endrin and heptachlor seed treatments showed a degree of type two repellency intermediate between lindane and aldrin on the one hand and untreated control seed on the other.