Pratylenchus hexincisus
Taylor and Jenkins, 1957
Photo Gallery- Konza Prairie
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Photo Gallery- Bloomfield,NE

Measurements (from Thorne & Malek, 1968)
L = 0.5 mm; a = 18; b = 5.4; c = 20; V = 80

Description (from Thorne & Malek, 1968)
Lateral fields marked by 6 incisures except toward extremities where they are reduced in number.  Near midbody these incisures may be broken into irregular lines.  Lip region bearing two annules. Spear 14u long with somewhat rounded knobs. Esophageal gland outlet near spear base.  Valve of median bulb anterior to center. Nerve ring surrounding base of isthmus. Basal bulb with overlap about as long as body width. Hemizonid just anterior to excretory pore. Anterior ovary outstretched with oocytes arranged in single file except for short region of multiplication. Posterior uterine branch about as long as body width. Tail slightly convex-conoid to broad, rounded terminus, with about 20 obscure annules. Males unknown.

Pratylenchus hexincisus is distinctive because of the six incisures, somewhat rounded spear knobs and broad rounded terminus of the convex-conoid tail.

Habitat:  Corn fields, Experiment Station Farm, Brookings, and Oakwood State Park, South Dakota. Probably generally distributed in heavier soils of South Dakota.

Measurements (from Taylor & Jenkins, 1957)
L = 0.342-0.540 mm; a = 18.2-28.8; b = 5.9-8.4; c = 16.1-22.7; V = 75.3-82.2; stylet = 14.5-15.4 um

Description (from Taylor & Jenkins, 1957)
    Female: The short and somewhat stout body tapers towards both ends.  The cuticle is marked with transverse striations about one micron apart, occurring slightly farther apart on the tail of some specimens.  The lateral field occupies about one-third of the body diameter in the vulvar region, originates as a narrow groove at the base of the stylet guiding apparatus, and contains six incisures throughout most of its length.  Outer incisures are crenate while the inner incisures are somewhat irregular, particularly in the vulvar region where breaks and oblique lines frequently occur.  Only four incisures occur on the tail.  No cervical papilla (deirid) was observed.  Phasmids occur in the anterior 1/4 - 2/5 of the tail.  The unstriated tail-tip is rounded.
    The low, flattened lip region bears one striation and its lateral margins are rounded in outline.  Lateral margins of the sclerotized cephalic framework extend posteriorly about one micron into the body cavity.  The stylet guiding apparatus is 3.2-3.6 um long.  The short, stout stylet has spherical basal knobs.
    The dorsal esophageal gland duct opens into the slightly convoluted lumen of the esophagus 2.2 um posterior to the stylet base.  The esophagus consists in part of the distinct corpus and an ovoid middle bulb which contains a heavily sclerotized valvular apparatus.  The excretory pore is located in the region of the isthmus; the nerve ring surrounds this same structure.  Esophageal glands ventrally overlap the intestine, which contains granules that are larger and more dense towards the ventral surface.  The dorsal esophageal gland nucleus is larger than the subventral nuclei.  The intestine terminates in an oblique rectum that opens through the cuticle by means of a conspicuous anus.
    The single outstretched ovary extends anteriorly about one-half of the body length.  Except for a double row in the anterior portion, the ovary contains a single row of oocyes.  An oviduct connects the ovary and the cellular uterus.  The cuticularized vagina extends transversely about one-half the body diameter and opens by means of a prominent vulva.  The short post-uterine branch is about equal to the body diameter at the vulva.  No spermatheca was observed.
    Male: Unknown.
Type host: Roots of corn, Zea mays.
Type locality: Le Cates farm, Kent County, Maryland.

DNA Sequences Obtained
Specimen: Collected:
KonzaIII CC-35 Konza Prairie, First survey
KonzaIII CC-40 Konza Prairie, First survey
KonzaIII GG-54 Konza Prairie, First survey