DISSIPATION KINETICS OF AZADIRACHTIN IN SOME FOREST MATRICES AND ITS SYSTEMIC TRANSLOCATION IN CONIFERS FOR SPRUCE BUDWORM CONTROL

Field microcosm studies were conducted to investigate the deposition, persistence, translocation and bioactivity of the botanical insecticid e azadirachtin-A (AZ-A) in young spruce trees. The deposition and pers istence of AZ-A in aspen foliage, forest soil and litter were also stu died. AZ-A residues in the different matrices were monitored at interv als of time after spray application of Neemix (R) 4.5 formulation at 1 00 g AZ-A in 2.3 L/ha. The dissipation half-lives in the matrices rang ed from 16.9 to 33.6 h. AZ-A was translocated and concentrated in the growing parts (especially the shoots) of spruce trees, after treatment by trunk injection (Tl), basal bark painting (BBP) and foliar paintin g (FP) of the Neemix 4.5 formulation. Systemically translocated and ac cumulated AZ-A residues in the shoots after Tl and FP were found to be effective against spruce budworm (Choristoneura furniferana Clemens.) larvae. Results suggest that Ti may be a useful way of using neem ins ecticide to protect high value trees from insect pests.