No abstract

In order to develop an effective trunk-injection agent against pine wood nematode, Bursaphelenchus xylophilus, an in vitro assay was used to examine the antinematodal activity of 58 commercially available compounds with known modes of action. Among compounds tested, the GABA receptor agonists had better anti-nematodal activity than compounds in¯uencing glutamate, Nmethyl-D-aspartate, b-adrenergic, dopamine, muscarinic acetylcholine and nicotinic acetylcholine receptors, as well as those inhibiting acetylcholinesterase, monoamine oxidase, 5-hydroxytryptamine uptake and Ca 2 , K , Na and Cl À channels. Avermectins and milbemycins strongly inhibited propagation of the nematode. Emamectin benzoate proved to be the most active (IC 95 0.050 mM) being over 140 times more active than the active ingredient of conventional trunk-injection agents. It is concluded that emamectin benzoate is a strong candidate for an anti-nematodal trunk injection agent.

particularly Mode I delamination, which is now a standard test for determining the fracture energies associated with interfacial (fiber-to-matrix) strengths in high-performance composite materials. The book's utility, however, lies in its being a convenient source of information on the important, and often poorly understood, world of chemistry of interfaces. Computer Integrated Manufacturing, Alan Wetherall, Editor, Butterworths, 1988, 299 pages.

In an earlier paper the authors reported the creation of a novel emamectin benzoate 40 g litre −1 liquid formulation (Shot Wan Liquid Formulation). The injection of this formulation exerted a preventative effect against the pine wilt disease caused by the pine wood nematode, Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, and this effect lasted for at least 3 years. The present study was carried out to show experimentally that the marked effect of this formulation was due to the presence and persistence in pine tissues of sufficient amounts of emamectin benzoate to inhibit nematode propagation. A cleanup procedure prior to quantitative analysis of emamectin benzoate by fluorescence HPLC was devised. The presence of the compound in concentrations sufficient to inhibit nematode propagation in the shoots of current growth and its persistence for 3 years explained the marked preventative effect. Non-distribution of emamectin benzoate in some parts of the lower trunk suggested that the formulation should be injected at several points for large trees in order to distribute the compound uniformly to lower branches.