Published online by Cambridge University Press: 31 May 2012
Post-attack injections of full- and half-strength Silvisar 510 (cacodylic acid) appear to inhibit populations of Dendroctonus rufipennis (Kirby) more effectively than quarter- and tenth-strength dilutions. Arsenic concentrations in the phloem were highest in the full-strength treatments and progressively decreased in the lesser strength treatments. Arsenic concentrations in the phloem were generally highest just above the frill while concentrations at 20 ft and higher above the frill were significantly lower than those just above the frill. Arsenic concentrations in the needles were highest in the full- and half-strength treatments and decreased progressively in the lesser strength treatments. Concentrations in the needles were essentially equal in the upper and lower portions of the crown. Arsenic concentrations in the soil were not affected by the treatments.