Bursaphelenchus xylophilus

Measurements (after Nickle et al., 1981)
Female lectotypes (n=5): L=0.52 (0.45-0.61) mm;a=42.6 (37-48);b=9.6 (8.3-10.5);c=27.2 (23-31);V=74.7 (73-78)%;stylet=12.8 (12.6-13.0) µm.
Male lectotypes (n=5): L=0.56 (0.52-0.60) mm;a=40.8 (35-45);b=9.4 (8.4-10.5);c=24.4 (21-29);stylet=13.3 (12.6-13.8) µm;spicule=21.2 (18.8-23.0) µm.
Measurements (after Mamiya and Kiyohara, 1972)
Female (n=40): L=0.81 (0.71-1.01) mm;a=40.0 (33-46);b=10.3 (9.4-12.8);c=26.0 (23-32);V=72.7 (67-78)%;stylet=15.9 (14-18) µm.
Male (n = 30): L=0.73 (0.59-0.82) mm;a=42.3 (36-47);b=9.4 (7.6-11.3);c=26.4 (21-31);stylet=14.9 (14-17) µm;spicules=27.0 (25-30) µm.
Description (after Nickle et al., 1981)
Female: cephalic region high, offset, with six lips. Stylet with small basal swellings. Oesophageal gland lobe slender and about 3-4 body-widths long. Excretory pore located at about the level of the oesophago-intestinal junction, occasionally at the same level as the nerve ring. Hemizonid about 0.67 of a body-width behind the median bulb. Vulva posterior, the anterior lip overhanging to form a flap. Genital tract monoprodelphic, outstretched. Developing oocytes mostly in single file. Post-uterine sac well developed, extending for 0.75 or more of the distance to the anus. Tail subcylindroid with a broadly rounded terminus. Mucron usually absent, but some populations may have a short, 1-2 µm, mucron.
Male: similar to female in general respects. Spicules large, strongly arcuate so that the prominent transverse bar is almost parallel to the body axis when the spicules are retracted. The apex is bluntly rounded and the rostrum prominent and pointed. The distal tip of each spicule is expanded into a disc-like structure named the cucullus. The tail is arcuate with a pointed, talon-like terminus bearing a small bursa. Seven caudal papillae are present;one pair adanal, a single preanal ventromedian papilla, and two postanal pairs near the tail spike and just anterior to the start of the bursa.