The genus Bursaphelenchus currently is composed of 43 species. The present study proposes reducing the number of valid species to 37. Diagnostic characters used for separating species were spicule shape and measurements, adult population length range, stylet length, "a" and "c" ratios, presence of the vulval flap, and vulva percentage. The unique shape of the spicule of Bursaphelenchus lends itself to species identification. The spicule has a capitulum with two characteristic projections. One is a ventral thorn-like projection called the rostrum, and the other is a dorsal thorn- or knob-like protuberance which is here named the "condylus." In some species, an accessory piece is present on the posterior end of the spicules, to which the name "cucullus" is given. The following species have been synonymized based on statistical cluster analysis and comparisons of morphometrics and morphology: B. naujaci Baujard, 1980 to B. bakeri Ruhm, 1964; B. pinasteri Baujard, 1980 to B. chitwoodi (R
