(Raski, 1952) Loof & De Grisse, 1989
|Criconemoides xenoplax Raski, 1952
Macroposthonia xenoplax (Raski, 1952) De Grisse
& Loof, 1965
Criconemella xenoplax (Raski, 1952) Luc &
Criconema pruni Siddiqi, 1961
Criconemoides pruni (Siddiqi, 1961) Raski &
Macroposthonia pruni (Siddiqi, 1961) De Grisse
& Loof, 1965
Mesocriconema pruni (Siddiqi, 1961) Andrássy,
Criconemella pruni (Siddiqi, 1961) Luc & Raski,
Criconemoides nainitalensis Edward & Misra,
FEMALE : 0.404-0.620 mm. ; a = 8.3-13.6; b = 3.1-4.8; c = 23.1-55.6; V
MALE : 0.530-0.610 mm. ; a = 22.5-27.7; b = ? ; c
= 12.4-15.3; T = 27.9-35.1%.
M-N). Head and tail bluntly rounded as in female. Sublateral
lobes present. Spear length 59-65 u. Total annules 96-114,
marked on posterior edge by fine longitudinal lines.
1, A-I, O, T). Oral aperture obscure at surface, internally shows
as a narrow slit near base of sclerotization. Conspicuous, elevated,
labial disc surrounding oral opening. Amphid apertures obscure appearing
as narrow, darkened slits on lateral margins of labial disc. Labial
disc expanded near base to include the amphidial pouches. Sclerotization
hexaradiate with internal innervations present in four submedian sectors.
Lateral sectors bearing elongate, indefinite innervations of amphids.
Sublateral lobes conspicuous, placed equidistant about the labial disc
and well separated from one another. The lobes project outward and
forward sometimes as far as edge of labial disc. In ventral view
the ventro-sublateral lobes appear connected. The same is true of
the dorso-sublateral lobes but there is no perceptible connection between
the sublateral lobes dorso-ventrally. These connections are obscure
in face view. First annule variable, usually divided into four labial
plates which may be simple, notched or indented. Labial plates may
also be reduced in number, rudimentary in size, complicated by anastomosis
with second annule or completely lacking. First two annules not retrorse,
smaller and narrower than succeeding body annules but not set off, presenting
a bluntly rounded outline.
Spear length 71-86 u. Excretory pore on 25-35th
annule from anterior end. Vulva on 6-11th annule from end of body,
generally on 7-8th. Anterior flap of vulva variable but usually presents
a bilobed appearance. Anastomosis with preceding or succeeding annules
often complicates vulva pattern. Ovary extends 40.2-79.0% of body
length. Anus located on 4-8th annule from end of body. Terminus
a simple rounded or lobed button. Total annules 87-114.
1, J-L, P-S). Details of face view exaggerated slightly for purposes
of illustration since they are somewhat obscure. Lip region definitely
elevated, no striae present on lips. Sublateral lobes small, placed
equidistant about the large labial disc. Innervations of amphids
appear to be present but amphid apertures obscure. Hexaradiate sclerotization
delicate, extending 4-5 annules posterior to lips, internal innervations
present in four submedian sectors.
Annulation coarse, 1.4-1.5 u wide near head, 2.8-3.1 u
wide midway. Lateral field marked by four incisures beginning as
two at about 6-7th annule from lip region. Faint cross striae present
in first part of lateral field. Esophagus indistinct, spear absent.
Excretory pore 0.132-0.138 mm. from anterior end of body. Herizonid
almost two annules wide, located 6-7 annules anterior to excretory pore.
Spicules 38-43 u long, slightly curved. Gubernaculum
simple, rod-like, 8-9 u long. Spicule sheath protrudes conspicuously,
bears a short, rod-like process on posterior edge. Tail constricts
posterior to spicules and is coarsely annulated to terminus which is bluntly
rounded. Bursa small, begins slightly anterior to cloacal opening
and extends almost to terminus. Lines of lateral field extend almost
to terminus on lateral sides of bursa.
Males rare, known only from type locality.
TYPE SPECIMENS. Holotpe-females, Catalogue
#1; allotype-male, Catalogue #2; 87 paratypes in Calif. Coll. #201 in University
of California collection, Berkeley.
TYPE HABITAT. Soil taken about roots of Thompson
seedless grape (Vitis vinifera var. sultanina) gorwn on #1613
(Vitis longii) rootstock.
TYPE LOCALITY. About 4 miles east of Fresno,
Fresno County, Calif.
DISTRIBUTION. This species was also collected
from many localities in California in soil about roots of walnut, plum,
California laurel (Umbellularia californica) and from a stream bank;
soil at roots of pine, Idaho Springs, Colorado; soil taken in woods near
Beebe Lake, Ithaca, N.Y. and soil from woods near Peconic, Long Island,
DIAGNOSIS. Criconemoides xenoplax keys
to C. rusticum according to Taylor (1936) but differs from it in
spear length and shape of head and tail. Micoletzky (1917) reported
the spear length of C. rusticum as 57.5 u and illustrated
the head and tail with blunt ends. The spear of C. xenoplax
is longer (71-86 u) and has the head and tail much more rounded
than is illustrated by Micoletzky. Goodey (1951) reports the spear
of C. rusticum as 50 u. He also pointed out that the
spear of C. rusticum illustrated by Taylor (1936) actually measured
Cobb (1918) described C simile with a “head surmounted
by a flat lip region composed probably of 6 very flat lips placed in a
slightly depressed front surface of the first annule . . . . No labial
papillae have been seen.” No spear measurement was given but it is
probable this species is similar to C. rusticum as illustrated by
Micoletzky and is so considered here. The specimens used by Chitwood
(1949) in reerecting C. simile had spear measurements of 70-75 u
and therefore were not C. rusticum. Further examination of
material used by Chitwood will be necessary to determine whether it is
the same as C. xenoplax.
(Original Description- Raski, 1952)
0.58 mm; a = 22; b = 4.8; c = ?; V = 95
Body cylindroid except extremities. Annules without anastomosis
except in rare instances. Sublateral labial lobes conspicuous.
Perioral disc rounded. First cephalic annule indented, not circular,
somewhat cupped; second slightly wider, definitely set off by constriction.
Remaining body annules rounded, slightly retrorse, numbering about 112.
Spear massive, 55u long, its muscles somewhat sclerotized in basal
third. Median bulb massive, tapering to a broad isthmus. A
minute cardia present. Excretory pore and hemizonid not observed.
Vulva usually on 6th or 7th annule from terminus. Ovary outstretched,
oocytes in single file except for a short region of multiplication.
Anus not definitely seen.
Habitat: Numerous females and young from Medicine Butte, S. Dakota
and one female from Fairmont, Nebraska.
(Description- Thorne and Malek, 1968)
species included in the Criconematid Project
DNA Sequences Obtained