Helicotylenchus

Contents

Rev 05/12/25

photo by Howard Ferris

Labial region continuous to slightly offset, rounded or anteriorly flattened, generally annulated, but never longitudinally striated; anterior lip annule generally not divided into sectors, with elongate amphid apertures (SEM). Rarely faint or marked lip sectors are present.

Lateral field with four lines.

Phasmids small, near anus; cephalids and caudalid present.

Tail 1 to 2.5 body diameters long, typically more curved dorsally, with or without a terminal ventral process, sometimes rounded.

Stylet and labial framework average sized.

Dorsal esophageal gland opening (DEGO) from 6 to 16 um from stylet base.

Median bulb rounded with average-sized valve.

Glands overlap intestine dorsally and ventrally, all three glands of about the same length.

Two genital branches, the posterior one sometimes degenerated or reduced to a post-uterine sac. Epiptygma present, but folded inwards into the vagina. Vulval flaps present, inconspicuous.

Male: Slight secondary sexual dimorphism seen in smaller anterior end.

Caudal alae enveloping tail end.

Fortuner, et al.(1987), and H. Ferris.