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Female
Body annulated, pearly white, globular to pear-shaped, with slight
posterior protuberance and distinct neck region projecting from the body
axis up at an angle of 90 degrees to one side. Head region set off from
body, marked with one of two annules. Head cap distinct but variable
in shape; labial disc slightly elevated. Cephalic framework weakly
sclerotized; vestibule extension distinct.
Stylet cone dorsally curved and shaft cylindrical; knobs large, rounded
to transversely ovoid; slightly sloping posteriorly from the shaft.
Excretory pore located between head end and metacorpus levels. One
or two large vesicle-like structures, and several smaller ones located
along the lumen lining. Pharyngeal glands variable in size and shape.
Perineal pattern ovoid to oval shaped, sometimes rectangular; dorsal
arch ranging from low to moderately high, with coarse striae. Tail
terminus indistinct without punctations. Phasmids small and difficult
to observe. Perivulval area devoid of striae. Lateral lines
indistinct (LM), appearing as a weak indentation under SEM, increasing
towards the tail terminus region and resulting in a relatively large area
without striae. Ventral pattern region oval to angular shaped; striae moderately
coarse.
Male
Body vermiform, slightly tapering anteriorly, bluntly rounded posteriorly.
Cuticle with distinct transverse striae. Lateral field with four
incisures; outer ones irregularly aerolated; a fifth broken longitudinal
incisure is rarely present near mid-body.
Head slightly set off, with a single post-labial annule (sometimes
called head region) usually partly subdivided with a transverse incisure.
Labial disc rounded, elevated and fused with medial lips. Prestoma
hexagonal in shape with six inner cephalic sensilla adjacent to the rim.
Medial lips crescent shaped with raised edges at lateral sides. Four
cephalic sensilla small and marked by cuticular depressions on the medial
lips. Amphidial openings appear as elongated slits between labial disc
and medium sized lateral lips. Cephalic framework moderately sclerotized,
vestibule extension distinct.
Stylet cone straight; shaft cylindrical; knobs large and rounded, set
off from the shaft. Pharynx with slender procorpus, metacorpus oval
shaped with pronounced valve. Ventrally overlapping pharyngeal gland
lobe variable in length. Hemizonid, 2-3 um in length, two
to four annules anterior to excretory pore.
Testis usually long, monorchic, with reflexed or outstretched germinal
zone. Tail short and twisted. Spicules slender, curved ventrally;
gubernaculum slightly crescent shaped. Phasmids located anterior
to cloaca.
Second-stage juveniles
Body moderately long, veriform, tapering at both ends but posteriorly
more than anteriorly. Body annules small but distinct. Lateral
field with four incisures, not areolated. Head region truncate, slightly
set off from body. Head cap low and narrower than head region.
Cephalic framework weakly sclerotized, vestibule extension distinct.
Stylet slender and moderately long, cone straight; shaft cylindrical;
knobs distinct, rounded and set off from the shaft. Pharynx with
faintly outlined procorpus and oval shaped metacorpus with distinct valve.
Pharyngeal gland lobe variable in length, overlapping intestine ventrally.
Hemizonid distinct at the same level with the excretory pore.
Moderately sized tail, gradually tapering until hyaline tail terminus,
with inflated proctodeum. Phasmids difficult to observe, small, slightly
posterior to anus. A rounded hypodermis marked the anterior position
of the smooth hyaline tail terminus ending in a broadly rounded tip.
Terminus generally marked by faint cuticular constrictions.
Eggs (n = 30)
Length 90 - 104 um (94 + 3.4); width 34.1 - 44.2 um
(38.9 + 3.2); length / width ratio 2.1 - 2.9 ( 2.4 + 0.2).
Hosts
In the field detected on different economical important crops like
potato and carrot, recent host tests indicate that it is able to parasitize,
like M. chitwoodi, on a wide range of mono- and dicotyledonous plants.
Both root-knot nematodes share hosts, but also species specific host have
been found. M. fallax induces on most plants relatively small
galls.
Host preference studies showed that Phaseolus vulgaris L. cv's
Iprin, Strike and Groffy, Zea mays L., Potentilla fruticosa
L. and Erica cinerea L. were good hosts for M. chitwoodi
but not for M. fallax. On the other hand M. fallax
reproduced well on Oenothera erythrosepala Borb., Phacelia tanacetifolia
Bentham, Dicentra spectabilis (L.) Lem. and Hemero callis
cv Rajah, while M. chitwoodi reproduced not or poorly (Brinkman
et
al., 1996)
Distribution
Detected so far in the southern part of the Netherlands, Belgium, Germany
(one location) and France (one location).
Type locality and host
Described from roots of tomato (Lycopersicon esculentum Mill.).
The nematodes were originally isolated from infected roots of black salsify
(Scorzonera hispanica L. ev. Lange Jan) from arable land one mile
north of Baexem, province of Limburg, the Netherlands.
(Description- Karssen, 2002)
DNA Sequences Obtained
Specimen: | Collected: |
VBA2-1A |