Pratylenchus codiaei
S.P. Singh and V.K. Jain, 1984
Body almost straight except near the vulva where it is slightly
bent ventrally and tapering slightly towards extremeties. Cuticle
finely striated, striations 1.2-1.4 um apart at mid body. Lateral
fields with four incisures and occupy 1/4th of the body width. At
the level of the metenchium, the origin place of the lateral field, there
are three incisures which become four behind nerve ring and continue up
to tail tip.
Head with two annules, rounded, continuous with body, 7-9 um
wide and 2.5-4.0 um high. Cephalic framework strongly sclerotized
and extends posteriorly up to one body annule. Two pairs of cephalids
(not seen in Holotype), first pair one annule behind the lip, second pair
seven annules behind the lip or at the level of the spear knobs.
Spear strongly developed, metenchium 7-9 um long, basal knobs rounded,
3-5 um across. Orifice of the dorsal oesophageal gland 2-4
um
from spear base. Procorpus cylindrical, 28.5 (23-34) um long.
Median oesophageal bulb spherical, 11-15 x 9-13 um. Oesophageal
glands 44 (35-52) um long, overlapping the intestine ventrally for
more than one body width as a long narrow lobe. Oesophago-intestinal
junction more or less at the level of excretory pore. Nerve ring
placed at 62 (55-70) um from anterior end, close to median oesophageal
bulb. Excretory pore posterior to the nerve ring, 78.5 (70-88) um
from anterior end. Hemizonid 3 annules wide, immediately anterior
to the excretory pore.
Vulva transverse, with small lips. Vagina slightly anteriorly
directed, 7-9 um long, occupying one-quarter to one-third of corresponding
body width. Reproductive system monodelphic, prodelphic, outstretched
and may extend up to median oesophageal bulb. Oocytes arranged in
a single row except in maturation zone. Spermatheca spherical without
sperms. Post-vulval uterine sac short, 12-16 um long, less
that one body width or 14-20 per cent of the distance between vulva and
anus. Vulva-anus distance 78 (68-88) um or about two and one-half
times tail length. Tail small, subcylindrical, 28 (23-34) um
long having 20 (18-22) annules, with smooth rounded to slightly conoid
terminus. Phasmids in the posterior half of the tail.
Male: Unknown
Habitat: From around the soil and within the roots of garden
croton (Cordiaeum variegatum).
Locality: Alambagh, Lucknow, India.
Type Specimens: Holotype and Paratype slides are in possession
of authors.
Differential diagnosis and relationship: According to the
key of Loof (1978) the new species comes closer to Pratylenchus scribneri
Steiner, 1943, P. neglectus (Rensch, 1924) Filipjev and Schuurmans
Stekhoven, 1941 and P. agilis Thorne and Malek, 1968. Although
ranges of V ratios of above species overlap, yet their mean values
are different enough to allow differentiation of one species from one another
(Roman and Hirschman, 1969).
From P. scribneri, the present species differs in having
stouter body, differently shaped head, longer oesophageal glands, posteriorly
located vulva, shorter vulva-anus distance, shorter post-vulval uterine
sac and lesser tail annules (in P. scribneri, a = 20-29, head offset,
oesophageal glands 35 (26-41) um long, V = 74-82 with average
never more than 77, vulva-anus distance 3 times tail length, post-vulval
uterine sac longer than vulval body width and tail annules 23 (21-25).
It differs from P. neglectus in having shorter spear with
rounded knobs, anteriorly placed vulva, differently shaped tail and lateral
fields without oblique striae (spear = 15-19 um, spear knobs indented
on anterior surface, V = 75-86 with average always more than 81.5,
tail almost conical and lateral fields with oblique striae in central zone
in P. neglectus).
The new species can be differentiated from P. agilis in
having stouter body, shorter spear, round spermatheca and posteriorly placed
vulva (a = 24, spear = 16-18 um, Spermatheca absent and V
= 76 in P. agilis).