Ditylenchus equalis Heyns 1964

4. Ditylenchus equalis Heyns, 1964 8 females: L = 749 (602–861) µm; stylet = 7.4 (7–8) µm; pharynx = 118 (98–145) µm; tail = 73.5 (51–91) µm; a = 44.8 (35.6–57.5); b = 6.4 (5.4–8.2); c = 10.4 (9.1–12.3); c′ = 6.6 (4.2–8.5); V = 80.6 (78.9–82.6); V′ = 89.3 (88.1– 90.5); PUS / VBW = 1.2 (1.0–1.4; in one specimen = 2.1); PUS /V-A = 30.6 (20.9–58.4) %; V-A/T = 1.0 (0.8–1.2). 4 males: L = 537 (494–565) µm; stylet = 7.3 (7–8) µm; pharynx = 116 (104–134) µm; tail = 51.2 (50–53) µm; a = 44.1 (39.1–48.7); b = 4.6 (4.2–4.9); c = 10.5 (9.7–11.1); c′ = 5.1 (4.6–5.5); spicules = 14.9 (14–16) µm. Diagnosis. D. equalis is characterised by four lateral field incisures, unstriated head, delicate, short stylet with rounded knobs, basal pharyngeal bulb pyriform to elongate and usually offset, sometimes with a slight overlap (up to 2 µm), posterior position of vulva, short post-vulval uterine sac, tail tip usually pointed and sometimes rounded, and short spicules. D. equalis is similar to D. deiridus Thorne & Malek, 1968, D. emus Khan, Chawla & Prasad, 1969, D. exilis Brzeski, 1984, D. filimus Anderson, 1983, D. parvus and D. terricolus. It differs from D. deiridus by having PUS (vs. PUS absent), and from D. emus and D. exilis by different shape of tail tip (usually pointed vs. rounded). It can be distinguished from D. filimus by shorter spicules (14–16 vs. 29 μm) and lower V index (78.9–82.6 vs. 81–85), from D. parvus and D. terricolus by greater V index (78.9–82.6 vs. 71–77) and lower PUS/VBW ratio (1.0–1.4 vs. 1.8–4.3 and 2.1–3.2, respectively).
Published as part of Hashemi, Kobra & Karegar, Akbar, 2019, Description of Ditylenchus paraparvus n. sp. from Iran with an updated list of Ditylenchus Filipjev, 1936 (Nematoda: Anguinidae), pp. 85-113 in Zootaxa 4651 (1) on page 92, DOI: 10.11646/zootaxa.4651.1.6, http://zenodo.org/record/3359134
{"references":["Heyns, J. (1964) Aphelenchoides helicus n. sp. and Ditylenchus equalis n. sp., two new soil inhabiting nematodes. South African Journal of Agricultural Science, 7, 147 - 150.","Thorne, G. & Malek, R. B. (1968) Nematodes of the northern Great Plains. Part I. Tylenchida (Nemata: Secernentea). South Dakota agricultural Experiment Station Technical Bulletin, 31, 1 - 111.","Khan, E., Chawla, M. L. & Prasad, S. K. (1969) Tylenchus (Aglenchus) indiens n. sp. and Ditylenchus emus n. sp. (Nematoda: Tylenchidae) from India. Labdev Journal of Science and Technology, 7 B, 311 - 314.","Brzeski, M. W. (1984) Three new species of Ditylenchus Filipjev, 1936, and comments on Basiroides longimatricalis Kazachenko, 1975 (Nematoda: Anguinidae). Nematologica, 29, 380 - 389. https: // doi. org / 10.1163 / 187529283 X 00267","Anderson, R. V. (1983) An emended description of Ditylenchus valveus Thorne & Malek, 1968 and description of D. filimus n. sp. (Nematoda: Tylenchidae) from mushroom compost in Canada. Canadian Journal of Zoology, 61, 2319 - 2323. https: // doi. org / 10.1139 / z 83 - 306"]}