Ditylenchus destructor Thorne, 1945

Hashemi, Kobra & Karegar, Akbar, 2019, Description of Ditylenchus paraparvus n. sp. from Iran with an updated list of Ditylenchus Filipjev, 1936 (Nematoda: Anguinidae), Zootaxa 4651 (1), pp. 85-113 : 90-91

2. Ditylenchus destructor Thorne, 1945

489 females: L = 994 (603–1468) µm; stylet = 10.3 (8–13) µm; pharynx = 134 (82–178) µm; anterior end to end of glands = 141 (89–204) µm; tail = 67.3 (39.5–90.5) μm; a = 36.6 (21.4–52.2); b = 7.4 (4.9–11.7); c = 14.8 (11.4– 27.8); c′ = 4.3 (2.6–7.2); V = 80.8 (77.1–84.9); V′ = 86.7 (78.4–89.8); PUS/VBW = 3.3 (1.7–4.6); PUS/V-A = 67.8 (36.9– 92.6) %; V-A/T = 1.8 (1.2–4.5).

422 males: L = 894 (600–1254) µm; stylet = 10.1 (8.5–12) µm; pharynx= 132 (103–162) µm; anterior end to end of glands = 138 (107–182) µm; tail = 63.3 (45–87.5) µm; a = 42.2 (27.1–59.5); b = 6.8 (4.8–9.0); c = 14.1 (11.0–19.1); c ′ = 5.0 (3.1–6.9); spicules = 22.0 (18–28) µm.

Diagnosis. D. destructor is distinctive because of its rather stout body, six lateral field incisures (sometimes with one to four additional lines), well-developed cephalic skeleton, moderately large stylet with distinct rounded to posteriorly sloping knobs, moderately developed median bulb with distinct valve, basal pharyngeal bulb of variable shape (usually pyriform to rather long) and often with a short overlap (with an average of 8 µm and sometimes up to 31 µm), posterior position of vulva, long post-vulval uterine sac, thick tail that narrows evenly from its midpoint to a usually rounded, but sometimes dull terminus, and long spicules. Most of the present data were obtained from nematodes under different feeding and temperature conditions, resulting in wide ranges form morphological and morphometric character values.

In comparison with morphological characteristics given by Brzeski (1998), the Iranian populations of D. destructor have different tail tip shape (often rounded, sometimes dull and seldom pointed vs. always rounded). D. destructor is close to D. arachis Zhang, Liu, Janssen, Zhang, Xiao, Li, Couvreur & Bert, 2014 , D. africanus Wendt, Swart, Vrain & Webster, 1995 , D. convallariae Sturhan & Friedman, 1965 , D. halictus Giblin-Davis, Erteld, Kanzaki, Ye, Zeng & Center, 2010 , D. longicauda Geraert & Choi, 1988 and D. oncogenus Vovlas, Troccoli , Palomares- Rius, De Luca, Cantalapedra-Navarrete, Liébanas, Landa, Subotin & Castillo, 2016, but none of these are pathogenic on potatoes. Moreover, D. destructor can be distinguished from D. arachis and D. africanus by its relatively longer spicules (18–28 vs. 16–24 and 15.5–22 μm, respectively) and different host preferences (non-pathogenic on peanut vs. pathogenic on it), from D. convallariae by different tail tip shape (rounded vs. pointed), from D. halictus by its relatively longer body (608–1468 vs. 560–774 μm), relatively larger spicules (18–28 vs. 16.5–21 μm) and different method of reproduction (bisexual vs. parthenogenetic), from D. longicauda by relatively larger spicules (18–28 vs. 16–23 μm), relatively greater PUS/VBW ratio (1.7–4.6 vs. 1.2–2.1) and different tail shape (thick with rounded tip vs. long and slender, with pointed to rounded tip), and from D. oncogenus by different tail terminus shape (rounded vs. rather pointed).