Ditylenchus dipsaci ( Kühn, 1857 ) Filipjev, 1936

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 : 91

3. Ditylenchus dipsaci ( Kühn, 1857) Filipjev, 1936

191 females: L = 1140 (878–1510) µm; stylet = 10.5 (9–13) µm; pharynx = 177 (143–221) µm; tail = 77.6 (53–105) µm; a = 46.1 (29.5–62.5; in one specimen = 18.5); b = 6.5 (5.0–8.4); c = 14.8 (11.5–25.7); c′ = 5.4 (3.7–7.7); V = 80.4 (75.8–87.3; in one specimen = 69.6); V ′ = 86.3 (74.1–93.9); PUS/VBW = 2.6 (1.5–3.6); PUS/V-A = 43.4 (25.6–77.8) %; V-A/T = 1.8 (0.8–2.4; in one specimen = 3.9).

134 males: L = 1103 (877–1346) µm; stylet = 10.5 (9.5–12) µm; pharynx = 175 (130–210) μm; tail = 76.5 (58–99) μm; a = 48.4 (33.8–66.5); b = 6.3 (5.2–8.1); c = 14.5 (12.0–18.3); c′ = 5.1 (3.5–7.4); spicules = 23.7 (20–28) µm.

Diagnosis. D. dipsaci is distinguished by its long, slender body, four lateral field incisures (sometimes with one to three additional lines), well-developed cephalic skeleton, moderately large stylet with distinct rounded knobs, moderately-developed median bulb with distinct valve, variable shape of basal pharyngeal bulb (usually long and cylindrical, sometimes pyriform and shorter, sometimes with a short stem), basal pharyngeal bulb usually with slight intestinal overlap, averaging 5 µm (seldom up to 29 µm) and sometimes offset, posterior position of vulva, long post-vulval uterine sac, thick tail with usually pointed, but sometimes dull tip, and long spicules.

The Iranian populations of D. dipsaci are similar to D. angustus ( Butler, 1913) Filipjev, 1936 , D. gigas Vovlas, Troccoli, Palomares-Rius, De Luca, Liébanas, Landa, Subbotin & Castillo, 2011 , D. laurae Skwiercz, Kornobis, Winiszewska, Przybylska, Obrępalska-Stęplowska, Gawlak & Subbotin, 2017 , D. solani , D. sturhani Mirbabaei Karani, Eskandari, Ghaderi, Heydari , & Miraeez, 2017 and D. weischeri Chizhov, Borisov & Subbotin, 2010 . They differs from D. angustus by relatively longer spicules (20–28 vs. 16–21 μm), less bursa/tail% (24.8–85.2 vs. approximately 100%), different shape of basal pharyngeal bulb (long and cylindrical vs. clavate). It can be distinguished from D. laurae by shorter body (878–1510 vs. 1523–2095 μm), shorter tail (53–105 vs. 104–127 μm), less a index (18.5–62.5 vs. 72.5–103) and PUS/VBW (1.5–3.6 vs. 4.3–5.6), shorter basal pharyngeal bulb (length/width = 1.9–5.8 vs. approximately 10) and the shape of tail tip (usually pointed vs. mucronate), from D. solani by having longer spicules (20–28 vs. 18–20 μm), the shape of basal pharyngeal bulb and tail tip (long and cylindrical and usually pointed vs. pyriform and dull to rounded, respectively), from D. sturhani with longer body 878–1510 vs. 656–865 μm), longer spicules (20–28 vs. 18.5–20.5 μm), greater PUS/VBW (2.6 (1.5–3.6) vs. 1.4 (1.0–1.9)) and different shape of tail tip (usually pointed vs. usually dull), from D. weischeri with greater c′ index (5.4 (3.7–7.7) vs. 3.7 (2.9–4.8)). In the description of D. weischeri , other differences with D. dipsaci such as shorter tail and spicules, greater c index, V-A, V-A/T and PUS length are also noted, that falls within the range of variation of different D. dispaci populations in the present study and are not useful. The closest species to D. dipsaci is D. gigas , which is distinguished only with shorter body length (878–1510 vs. 1270–1932 μm).