Ditylenchus angustus

Measurements From Rice at Joydevpur, Bangladesh (Seshadri & Dasgupta, 1975) 15 females: L = 0.8-1.20 mm;a = 50-62;b = 6-9;c = 18-24;V = 78-80;stylet = 10-11 µm. 10 males: L = 0.7-1.18 mm;a = 40-55;b = 6-8;c = 19-26;T = 60-73;spicules = 16-21 µm;gubernaculum = 6-9 µm;stylet = 10 µm. 6 juveniles: L = 0.5-0.7 mm;a = 41-60;b = 6-9;c= 14-18;stylet = 8-10 µm. From Type Host and Locality (after Butler, 1913) females: L = 0.7-1.1 (0.9) mm;a = 47-58 (50);width= 15-22 (19 µm);b = 7.0 (?);c = 15-23 (20);V = 70-80;stylet = 9 or 10 µm. eggs = 80-88 µm x 16-20 µm. males: L = 0.6-1.1 mm;a = 36-47 (44);width = 14-19 µm;b = 7 (?);c = 18-23;stylet = 9 or 10 µm. After Goodey, 1932 females: L = 0.7-1.23 mm;a = 36-58;b = 7-8;c = 17-20;V = 80;stylet = 10 µm. males: L = 0.6-1.1 mm;a = 36-47;b = 6-7;c = 18-23;stylet = 10 µm. Description (after Seshadri and Dasgupta, 1975) Female Body slender, almost straight to slightly arcuate ventrally when relaxed by application of gentle heat. Cuticle with fine transverse striations;annules about 1 µm wide at mid-body. Lip region unstriated, not distinctly set off from the body, low, flattened, wider than high at lip base. Cephalic framework lightly sclerotized, hexaradiate, en-face view showing six lips of almost equal size. Lateral fields one-fourth of body width or slightly less, with 4 incisures, outer incisures more distinct than inner ones, extending almost to tip of tail. Deirids immediately posterior to the level of excretory pore. Phasmids close behind mid-part of tail, pore-like, difficult to see. Stylet moderately developed, conus attenuated, about 45% of total stylet length;knobs small but distinct, usually with posteriorly sloping anterior surfaces, rather amalgamated with one another, about 2 µm across. Procorpus cylindrical, narrows as it joins median oesophageal bulb, as long as 3-3.6 times body-width in that region. Median oesophageal bulb oval, with a distinct valvular apparatus anterior to the centre. Isthmus narrow, cylindrical, 1.5 to 1.9 times as long as procorpus;posterior oesophageal bulb usually clavate;27-34 µm long, slightly overlapping the intestine, mainly on the ventral side, with 3 distinct gland nuclei. Cardia absent. Nerve ring conspicuous, 21-35 µm behind median oesophageal bulb. Excretory pore 90-110 µm from anterior end, slightly anterior to beginning of posterior oesophageal bulb. Hemizonid 3-6 µm anterior to excretory pore. Vulva a transverse slit, vaginal tube somewhat oblique, reaching more than half-way across body. Spermatheca very elongated, packed with large, rounded sperms. Anterior ovary outstretched, oocytes in single row, rarely in double rows. Post-uterine sac collapsed, without sperms, 2.0-2.5 times as long as vulval body width, extending about 1/2 to 2/3 distance to anus. Tail conoid, 5.2 to 5.4 times the anal body width in length, tapering to a sharply pointed terminus resembling a mucro. Male As numerous as females. Body almost straight to slightly curved ventrally when fixed. Morphology similar to females. Caudal alae (bursa) present, narrow in some specimens, beginning opposite the proximal end of spicules, extending almost to tail tip. Spicules curved ventrally, simple;gubernaculum short, simple. Juveniles Similar to adults in gross morphology, oesophagus proportionally longer than in adults. Additional morphological and morphometric data was provided by Mian and Latif (1995). Type Host and Locality Oryza sativa, in Eastern Bengal (= Bangladesh).