Description (female): Body cylindrical, assuming C shape after death; lip region without visible annuli by light microscope, not offset; after 13-18 anterior annuli, body increasing rapidly in diameter, and body annuli inconspicuous. Labial region (SEM) with two annuli and a few longitudinal lines; oral disc small, not prominent; oral opening circular; amphid aperture pore-like, located at lateral edges of oral disc. Lateral field with four main distinct lines, and many longitudinal fine lines between them. Cephalic framework weak. Sytlet with fine cone and distinct shaft; stylet knobs oriented posteriorly without anterior projections. Procorpus variable in width, gradually widening to connect with median bulb (metacorpus), slight constriction between procorpus and metacorpus. Lumen in procorpus displaced to ventral side by contents and duct of dorsal esophageal gland. Median bulb oblong, valve distinct (crescentic thickenings) distinct constriction at metacorpus-isthmus junction; isthmus of variable width, distinct constriction at junction with esophageal glands; lumen in isthmus also displaced to ventral side by contents of esophageal glands. Three esophageal glands present, two of them small and half the size of the large central gland; generally, one small gland dorsal and one ventral to large central gland, nuclei small but distinct. Central esophageal gland, a long, large lobe, nucleus conspicuous. Esophageal lumen passing through central gland tojunction with intestine. Excretory pore located at level of posterior end of isthmus or anterior extreme of esophageal glands, hemizonid immediately anterior to excretory pore; nerve ring located in the middle of the isthmus or light posterior to it. Ovary with one or two flexures, sometimes straight and extending to esophagus. Ovarty two or five cells in width, continuous with oviduct; lumen of oveduct clear, continuous with the columella; columella along tube, five or six hexagonal cells wide, more than 14 cells long; contiunous with short thick walled uterus, connected to vagina on one side, and postuterine sac on the other. Postuterine sac containing degenerate cells. Vulval lips distinct. Tail conical, sharply pointed tip.
Males (n = 17): L = 1.22-1.84 mm (1.56 mm +
0.075); a = 21.1-33.0 (27.9 + 1.71); b = 5.8-10.4 (9.05 +
0.79); c = 19.8-29.8 (23.2 + 1.25); stylet = 9.3-12.7 um
(11.0 um + 0.46); dorsal gland orifice = 1.3-3.1 um (2.0
um + 0.26); median bulb length = 25.5-20.0 um (18.2 +
0.84); median bulb width = 11.3-16.5 um (13.3 um + 0.75);
esophagus length = 142.1-242.0 um (179.5 um + 17.3); isthmus
= 30.3-72.4 um (40.2 um + 5.72); dorsal esophageal gland
length = 24.1-68.9 um (56.4 um + 7.7); esophageal gland width
= 10.0-32.7 um (19.7 + 3.7); excretory pore = 98.9-137.9
um (127.0 um + 5.4); T = 58.6-82.1% (68.7% + 4.7);
caudal alae = 60.3-84.5 um (72.1 um + 4.8); spicules
= 26.2-40.7 um (34.2 um + 2.7); gubernaculum = 10.6-15.5
(13.0 um + 0.61); tail = 58.3-76.9 um (68.7
Allotype (male): L = 1.84 mm; a = 31.7; b = 10.4; c = 25.2; stylet - 12.7; esophagus = 175.2 um; excretory pore = 141.0 um; tail = 73.1 um; T = 67.9%; spiculues = 41.4 um; gubernaculum = 11.4 um.
Description (male): Body cylindrical, arcuate with ventral surface outermost after death. Labial region continuous with body contour, not offset, with two annuli and irregular longitudinal lines when viewed by SEM. In face view labial disc small and rhomboidal; oral opening circular; amphids pore-like and located laterally on outer margin of first annulus. Approximately 13 distinct body annuli visible posterior to labial disc, posteriorly from this point, body width increasing gradually, and body annuli become fine or obscure. Stylet short with distinct shaft, knobs rounded without anterior projections. Dorsal gland orifice distinct, gland contents displacing esophageal lumen to ventral side. Procorpus variable in width, slightly swollen near connection with median bulb, a slight constriction separating these two structures. Median bulb oblong with distinct valve (crescentic thickenings), connected with isthmus by distinct constriction; isthmus increasing gradually in width until constriction at esophageal glands. Two subventral glands almost one-half the size of dorsal gland, in most cases one subventral gland ventral and one dorsolateral. Dorsal glalnd forming major lobe. Esophageal lumen connecting with intestine at posterior extreme of dorsal gland; little or no gland overlap of intestine. Nerve ring located around posterior or middle region of isthmus. Excretory pore at level of connection of isthmus and esophageal glands or slightly posterior to it. Testis often with flexures, sometimes reaching median esophageal bulb. Spermatozoa globular with granular appearance. Spicules slightly arcuate, distally conical. Gubernaculum short with slight anterior projection and acute terminus. Caudal alae leptoderan, beginning anterior to spicules and ending before tail tip. Tail with acute terminus.
Second-stage larvae (n = 20): L = 0.63-0.97 mm (0.71 mm + 0.043); a = 37.0-56.4 (43.8 + 2.1); b = 3.5-7.3 (4.5 + 0.41); c = 8.8-11.4 (9.9 + 0.35); stylet = 10.0-12.7 um (11.0 um + 0.35); dorsal gland opening = 1.7-3.4 um (2.4 um + 0.23); median bulb length = 12.4-15.9 um (13.9 um + 0.44); median bulb width = 7.9-10.7 um (9.0 + 0.34); esophagus length = 124.4-196.5 um (159.2 um + 8.3); isthmus (n = 9) = 24.1-41.4 um (28.8 um + 4.0); dorsal esophageal gland length = 46.5-68.9 um (61.4 um + 8.6); dorsal esophageal gland width = 6.9-11.4 um (9.3 um + 1.3); excretory pore = 92.8-124.5 um (103.8 um + 4.9); tail = 58.6-82.4 um (70.4 um + 3.2); genital primordium to anterior end (n = 7) = 0.31-0.45 mm (0.37 mm + 0.04).
Body slender, outstretched, annulation fine; head flattened without annulation or constriction from rest of body. Stylet thin, knobs round, projecting slightly posteriorly. Cephalic framework weak. Procorpus irregular in width and continuous with median bulb, no constriction present; isthmus elongate, posterior extreme slightly wider than anterior, no constriction present at junction with esophageal glands. Nerve ring between level of metacorpus and excretory pore. Excretory pore obscure, located at level of nerve ring. Hemizonid immediately anterior to the excretry pore. Subventral glands less than one-half size of dorsal gland. Dorsal gland large with conspicuous nucleus in posterior extreme. Genital primoridium oval, 14.5-19.3 um by 5.1-8.9 um, composed of three cells, central cell largest nucleus conspicuous, external cells small and triangular. Tail long and tapering, with acute tip.
Type locality: Pebble Beach Golf Course, San Mateo County, California.
Type habitat: Galls in the base of the stem of bluegrass (Poa annua L.).
DNA Sequences Obtained
|HMB GC-1||Half Moon Bay, California|
|HMB-GC-6||Half Moon Bay, California|
|HMB-GC-3||Half Moon Bay, California|