Formulation and application of methoxychlor for elm bark beetle control.

American elm trees, Ulmus americana L., were sprayed with different formulations of methoxychlor by mistblower, hydraulic sprayer or helicopter. Twig-crotches were collected from sprayed trees for GLC assay and Scolytus multistriatus (Marsham) bioassay. Hydraulic deposits were heaviest but the mistblower was more efficient in terms of amount deposited per pound of methoxychlor sprayed. Helicopter deposits were light on lower branches but were comparable to mistblower and hydraulic deposits in tops of trees, where protection is needed most.