Achromadora tenax (de Man, 1876) Micoletzky, 1925

P. A. A. LOOF, 1971, FREELIVING AND PLANT PARASITIC NEMATODES FROM SPITZBERGEN, COLLECTED BY MR. H. VAN ROSSEN, Mededelingen Landbouwhogeschool Wageningen 71, pp. 1-86 : 55

Achromadora tenax (de Man, 1876) Micoletzky, 1925 (

Fig. 17 , C - D).

Dimensions of 15 females: L = 0.38 -0.42 mm; a = 23 -27; b = 5.7-6.3; c = 6. 1- 7. 3; V = 46-48.

Head end more rounded, less obviously truncated than in most other species of this genus. Mouth cavity weakly sclerotized, its details indistinct. Amphids rather inconspicuous, spiral; located about 14 \i (more than two head widths) from anterior end. Cuticular annulation resolvable into dots. Terminal bulb of oesophagus strongly developed. Vulva lips somewhat protruding. Cephalic setae very short and inconspicuous, directed almost laterad. Tail bent strongly ventrad, often 180 °; its length equal to 5.5- 7.3 anal body widths. Rectum 2.3-3. 1 anal body widths long, its anterior half strongly inflated. Spinneret tube tapering, about 2 JA long.

Samples 3, 7, 8, 10, 21, 26, 27, 29, 30, 31, 32, 37, 38, 40, 41, 55, 62, 66 and 69.

Generally A. tenax is regarded a synonym of A.dubia (Bütschli, 1873) . However, the identity of the latter is wholly uncertain, because the original description is totally inadequate. Bütschli did not give any dimensions; he only gave an illustration of the head end, showing a transversely oval amphid with central spot; and rather long cephalic setae, directed obliquely anteriad. Transverse striation of cuticle strongly developed. I regard this species as species dubia . Micoletzky's redescription (1925) states that the mouth cavity possesses three teeth, the amphids are apparently round, but really spiral. Cephalic setae short and fragile. It is better to call this species by the next available synonym, tenax (de Man, 1876) . The Spitzbergen specimens conform rather well to de Man's description except that the head end is less truncate.

Figures

FIG. 17. A-B: Achromadora semiarmala Altherr, female.A: neck region; B: tail. C-D: A.tenax (de Man), female. C: neck region; D: tail. E-F: A.ruricola(de Man),female.E: neckregion; F: tail.