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 th e large pine weevil, Hylobius abietis L. (Col. Curculionidae), consist ed of repeated insecticide treatments by dipping or spraying with orga nochlorine or pyrethroid insecticides. The use of a controlled-release formulation as Marshal/SuSCon containing the systemic carbamate insec ticide carbosulfan in nurseries or on reforestation sites as a single treatment at planting time ensures a good level of protection: Using g as chromatography as a standard analytical method, carbofuran, a bypro duct of carbosulfan, was detected and-admitted to be the effective pro duct. Its penetration in young plants is quick, and high levels of thi s product are observed 24 months after treatment. Comparisons between nursery and field trials show good protection of young Douglas firs ov er the critical period of establishment of the plantation with this fo rmulation.