Penetration and Persistence of Systemic Insecticides in Seeds and Seedlings of Southern Pines

Abstract

Effects of 5 organophosphate systemic insecticides on the germination of 5 species of southern pine seeds were investigated. Germination of seeds treated with Orthene^®, (O,S-dimethyl N-acetyl phosphoramidothioate) dicrotophos, and dimethoate was relatively high in comparison with reduced germinations after treatment with Monitor^® (O,S-dimethyl phosphoramidothioate) and phorate. Orthene produced the best results, with excellent penetration into seeds and high mortality of bioassay insects at low dosage rates and short treatment periods. Orthene was present in 4-week-old seedlings in quantities high enough to kill more than 60% of the pales weevil, Hylobius pales (Herbst), used as bioassay insects.