First record of the genus Bursaphelenchus Fuchs, 1937 in Thailand and description of B-thailandae sp n. (Nematoda: Parasitaphelenchidae)

Wood samples were taken from pine trees in the mountainous region between Pai and Maehongson in northern Thailand. Four species of Bursaphelenchus were recovered from the samples: Bursaphelenchus hylobianum, B. mucronatus, B. aberrans and B. thailandae sp. n. Bursaphelenchus thailandae sp. n. is most similar to B. sychnus but also shows similarities with B. ruehmi, B. hunanensis and B. steineri. It has a relatively small stylet lacking distinct basal knobs and a lateral field with four lines. The female has more or less protruding vulval lips and a slim, conoid, tail. The relatively small and delicate spicules show a distinctive darker sector and lack a cucullus. The male tail has a very small terminal 'bursa'. Bursaphelenchus thailandae sp. n. is tentatively included in the B. fungivorus-group of the genus Bursaphelenchus. Brief notes and morphometric data are given for the other species found. The record of B. mucronatus indicates that conditions for the establishment of the closely related B. xylophilus (the cause of pine wilt disease) may be suitable in Thailand and strict phytosanitary measures are therefore advisable.