Helicotylenchus californicus
Sher, 1966

0.7 mm; a = 25; b = 5.1; c = 33; V = 60
0.64 mm; a = 33; b = 4.5; c = 29; T = 35

Body of female always spiral when relaxed. Annules decreasing in width near lip region which is marked by 3 or 4 striae. Spear 26u-28u long with flat to slightly cupped knobs. Dorsal esophageal gland outlet about 8u behind spear. Cephalids usually 3 and 7 annules behind lip region.  Hemizonid about 1 annule wide, anteriorly adjacent to excretory pore. Phasmids varying in position from opposite anus to 6 or 7 annules anterior. Terminus varying from blunt to subdigitate. Spicula 22u long, slightly arcuate, resting on a thin trough-like gubernaculum.  Tail ventrally irregular with slender terminal portion.  Bursa rising about opposite proximal ends of spicula and enveloping tail.

Helicotylenchus californicus is distinctive because of being bisexual, usually digitate terminus, spear under 28u long with flat to slightly cupped knobs.

Habitat:  Cultivated fields and native grass near Aberdeen, Avon, Gary, Watertown and Wessington, South Dakota.