Ditylenchus myceliophagus Goodey, 1958

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 : 94-95

7. Ditylenchus myceliophagus Goodey, 1958

348 females: L = 734 (481–1108) µm; stylet = 7.7 (6–9) µm; pharynx = 119 (87–162) µm; anterior end to end of glands = 127 (87–187) µm; tail = 56.0 (33–85) µm; a = 38.1 (22.8–56.0); b = 6.2 (4.3–8.8); c = 13.2 (8.5–18.9); c′ = 4.6 (2.8–7.2); V = 80.8 (73.9–85.3); V′ = 87.6 (82.1–92.5); PUS/VBW = 2.1 (0.8–3.7); PUS/V-A = 45.5 (17.3–69.6) %; V-A/T = 1.5 (0.8–2.4).

201 males: L = 701 (426–939) µm; stylet = 7.7 (6.5–9) µm; pharynx = 120 (86.5–168) µm; anterior end to end of glands = 126 (92–168) µm; tail = 52.8 (39.5–76) µm; a = 40.6 (27.8–56.7); b = 5.9 (3.7–8.4); c = 13.4 (8.6–18.7); c′ = 4.5 (3.2–6.5); spicules = 18.9 (14.5–23.5) µm.

Diagnosis. D. myceliophagus is distinctive because of its thin to stout body, six lateral field incisures (sometimes with one to three additional lines), refractive, short crescentic cephalic skeleton, delicate, short stylet with rounded or posteriorly sloping knobs, variable shape of basal pharyngeal bulb (pyriform, cylindrical or elongate), basal pharyngeal bulb offset or with slight to long overlap, up to 66 µm, variable vuvla position and length of postvulval uterine sac, a usually thick tail that suddenly narrows from about half to the last two thirds, with a usually rounded, sometimes dull, tip, and variable spicule length.

Unlike the original description of D. myceliophagus ( Goodey 1958) , the head of different populations in this study was striated. The general shape of tail in the Iranian populations was more diverse than the Brzeski populations (1998) (usually thick and sometimes narrow vs. always thick). The Iranian populations of D. myceliophagus are close to D. acutatus , D. anchilisposomus , D. apus , D. dauniae , D. elegans , D. geraerti , D. medicaginis , D. silvaticus , D. tenuidens , D. triformis and D. valveus . D. myceliophagus can be distinguished from all of these species by its crescentic and refractive cephalic skeleton. In addition, it differs from D. acutatus with a lower PUS/VBW ratio (2.1 (0.8–3.7) vs. 3.5 (2.8–4.1)) and different tail shape (usually thick, with rounded tip vs. thick, with pointed tip), from D. apus by greater PUS/VBW ratio (0.8–3.7 vs. 0.2–0.4) and different shape of basal pharyngeal bulb (pyriform to elongate and offset or with overlap vs. elongate with long overlap), from D. elegans by its shorter body (481–1108 vs. 1030–1370), shorter tail (33–85 vs. 111–149 μm), relatively greater V (73.9–85.3 vs. 71–77), lower PUS/VBW ratio (0.8–3.7 vs. 3.2) and different tail shape (usually thick with rounded tip vs. narrow with pointed tip), from D. medicaginis to some extent by tail shape (usually thick with rounded tip vs. narrow with often pointed to dull tip), from D. silvaticus by different tail shape (usually thick with rounded tip vs. thick with pointed or rounded tip with mucron), from D. tenuidens by striated head (vs. smooth) and different tail tip (usually rounded vs. sharply pointed), from D. triformis by longer spicules (14.5–23.5 vs. 13–15 µm) and six incisures vs. four at anus region, and from D. valveus , to some extent, by tail shape (usually thick with rounded tip vs. narrow with often dull to rounded terminus). In the case of individuals with offset basal pharyngeal bulb or slight overlap over intestine, the basal plate of the cephalic skeleton is the only difference between D. myceliophagus and D. dauniae and D. geraerti , also if there are individuals with long basal bulb overlap over intestine, this feature is again the only difference between D. myceliophagus and D. anchilisposomus .