DETERMINATION AND UPTAKE OF CARBOSULFAN AND CARBOFURAN IN YOUNG DOUGLAS-FIRS (PSEUDOTSUGA-MENZIESII MIRB)

Protection of young Douglas firs and other conifers from attacks by the large pine weevil, Hylobius abietis L. (Col. Curculionidae), consisted of repeated insecticide treatments by dipping or spraying with organochlorine or pyrethroid insecticides. The use of a controlled-release formulation as Marshal/SuSCon containing the systemic carbamate insecticide carbosulfan in nurseries or on reforestation sites as a single treatment at planting time ensures a good level of protection: Using gas chromatography as a standard analytical method, carbofuran, a byproduct of carbosulfan, was detected and-admitted to be the effective product. Its penetration in young plants is quick, and high levels of this product are observed 24 months after treatment. Comparisons between nursery and field trials show good protection of young Douglas firs over the critical period of establishment of the plantation with this formulation.