Volume 1, Part 1 (1993)
and N.N. Zakharenkova. Occurrence in Russia of Wachekitylenchus
bovieni (Wachek, 1955) Slobodianiuc, 1986 (Tylenchida: Parasitylenchidae)
a parasite of beetles belonging to the genus Bembidion (Carabidae),
and S.E. Spiridonov. Nematimermis enoplivora gen. n., sp.
n. (Nematoda: Mermithoidea) from marine free-living nematodes Enoplus
Evolution of modified food cells induced by sedentary nematodes in plant
and S.A. Subbotin. Xiphinema species from the Surchandarja
region of Uzbekistan, 27-30.
of the family Ungellidae Chitwood, 1950 from Laotian earthworms, 31-40.
species of the marine free-living nematodes of the genus Rhips Cobb,
1920 (Chromadorida: Chromadoridae) from the Kuril Islands waters, 41-45.
and O.I. Belogurov. Apodontium bellum sp.n. and Aequalodontium
gemellum gen.n, sp.n. (Nematoda: Axonolaimidae) with remarks on Apodontium
B. Boag and C.A. Hackett. Observations on the use of Taylor's power
law to describe the horizontal spatial distribution of marine nematodes
in an intertidal estuarine environment, 55-64.
Longidoridae and their associated viruses in the Americas, 65-68.
Book Reviews, 69-71.
Chizhov, V.N. and
Occurrence in Russia of Wachekitylenchus bovieni
1955) Slobodianiuc, 1986 (Tylenchida: Parasitylenchidae) - a parasite of
beetles belonging to the genus Bembidion (Carabidae)
Additional information about the morphology, biology and distribution
of Wachekitylenchus bovieni (Wachek, 1955) Slobodianiuc, 1986 is
given. Also a degenerated male formed inside a parthenogenetic female is
Tchesunov, A.V. and
Nematimermis enoplivora gen.n.,sp.n.(Nematoda: Mermithoidea)
from marine free-living nematodes Enoplus spp.
Nematimermis enoplivora gen.n., sp.n. is described from the pseudocoel
of marine free-living nematodes Enoplus spp. Infestation of the
littoral and sublittoral nematodes E. brevis and E. communis
respectively from Kandalalsha Bay of the White Sea by juveniles and mature
females was observed during the summer seasons of 1986-1988. Four large
and two smaller stichocytes were present near the oesophageal tube of parasitic
juveniles. N. enoplivora gen. n., sp. n. grows to maturity inside
the host, and almost all inner tissues are strongly degenerated in females
filled with juvenile-bearing eggs. N. enoplivora gen. n., sp. n.
is probably an aberrant marine form of the family Tetradonematidae.
Key words: mermithids, tetradonematids, Nentatimermis
gen. n., marine host.
Evolution of modified food cells induced by sedentary
nematodes in plant roots
The development of modified food cells induced by sedentary nematodes
in plant roots are discussed as an example of host-parasite coevolution.
The main principles of this evolutionary process are reviewed. Analysis
of structures of the modified cells suggests that evolution of these cells
is connected with increases of cellular functional activity. Intensification
of modified cell function is achieved through multiplication of cell protoplast,
proliferation and polymerization of organelles and intensification of contact
between cell wall and protoplasm. Increase of functional activity matches
the evolution of modified cell development, from nonhypertrophic nurse
cells and single giant cell to syncytia and more specialized coenocytes.
Increased internal organisation of the modified cells is generally coincident
with the level of evolutionary advancement of the nematode. The hypothesis
of different levels of evolutionary development of modified cells can be
used to help determine systematic and phylogenetic relationships between
Key words: host-parasite coevolution, plant reaction,
sedentary nematodes, modified food cell.
S.K. and Subbotin, S.A.
Xiphinema species from the Surchandarja region of Uzbekistan
A preliminary survey of Xiphinema species was carried out in
the Surchandarja region of Uzbel:istan. Three species of Xiphinema:
brevicolle, X. index and X. pachtaicum were found in the rhizosphere
of subtropical wood cultures. The latter two species were widespread in
the region. Morphological characteristics, morphometrics and the distribution
of the species are presented.
Key words: Xiphinema spp., distribution, morphometrics, Uzbekistan.
Nematodes of the family Ungellidae Chitwood, 1950 from
Four new species of Sicotiema Timm, 1966 and Synoecizema
Iaotense sp. n. are described from laotian earthworms. Siconema
inaeqwcrazsum sp. n. is distinguished by the thin cephalic hooks, circular
suckers in both sexes and mammilate ornamentation on the egg surface. S.
aequicrassum sp. n. is similar to S. itiueqwcrassum sp. n.,
but differs in egg-shell, oesophagus and hook measurements. Siconema
Iaotense sp. n. is characterized by very large cephalic hooks. Siconema
aculeatum sp. n. has very characteristic rod-like appendages on the
egg surface. A unique feature of Synoectema Iaotense sp. n. is the
presence of a singular cephalic hook.
Key words: Drilonematoidea, Siconema, Synoecnema,
species, earthworm hosts.
New species of the marine free-living nematodes of
the genus Rhips Cobb, 1920 (Chromadorida: Chromadoridae) from the
Kuril Islands waters.
Rhips orientalis sp. n. was found in the sandy sediments at
a depth of 33 m, close to Shumshu Island (Northern Kuril). It is distinguished
from the five known species of the genus by the larger size of its body,
oesophagus and spicula measurements, structure of the anterior end cuticle
and the values of the De Man indices 'b' and 'c'. A key for the identification
of Rhips species is given.
Key words: new species, key, Rhips spp, marine
nematodes, Chromadoridae, Kuril Islands.
O.I. and Belogurov, O.I.
Apodontium bellum sp.n. and Aequalodontium gemellum
gen.n, sp.n. (Nematoda: Axonolaimidae) with remarks on Apodontium
Apodontiurn bellum sp. n. and Aequalodontium gemellum
gen. n., sp. n. are described from coarse-sand bottom samples collected
close to the East coast of Iturup Island (Kuril Archipelago). The original
description of Apodontium pacificum Cobb, 1920 is discussed. Some
structures mentioned by Cobb for A. pacificum are reconsidered.
A new genus Aequalodontium, proposed for A. gemellum sp.
n., resembles Margonema, Apodontium and
differs from Margonema and Apodontium in having telamon,
by the shape of the amphidial pouch and the spicula capitulum.
can be distinguished from Parascolaimus only by the presence of
the anterior male gonad.
Key words: Apodontium bellum sp. n., Aequalodontium
gemellum gen. n., sp. n., marine nematodes, Axonolaimidae, morphology.
Neilson, R., Boag, B.
and Hackett, C.A.
Observations on the use of Taylor's power law to describe
the horizontal spatial distribution of marine nematodes in an intertidal
The horizontal spatial distribution of marine nematodes at species,
genera and family level in an intertidal estuarine environment have been
investigated using Taylor's power law index of aggregation B. Different
transfomations were investigated for their ability to normalise the distributions.
Nine of the 15 nematode species; six of the eight genera and five of the
six families investigated had B values not significantly different from
2.0. For these a logarithmic transformation would stabilise the variance
of the distributions prior to further statistical analysis. The remaining
species, genera and families had b values which were significantly less
than 2.0. For these a variance-stabilising transformation is given by z=x1-B/2.
Some of the detailed information yielded at species and genera level was
lost after re-analysing the data at family level.
Key words: aggregation, estuarine, marine nematodes,
patchiness, spatial distribution, Taylor's power law.
Virus-vector Longidoridae and their associated viruses
in the Americas
Five Xiphinema and one Longidorus species have been identified
as natural vectors of nepoviruses in the Americas. Xiphinema index
is the vector of grapevine fanleaf virus (GFLV) and was the first virus
vector to be identified. Evidence suggests that the X. index - GFLV
association probably evolved elsewhere and was imported to the Americas
with grapevines. All native Xiphinema vectors belong to the Xiphinema
americanum-group of nematodes and transmit tomato ringspot, tobacco
ringspot,cherry rasp leaf, or peach rosette mosaic nepoviruses. Longidorus
diadecturus is also a vector of peach rosette mosaic nepovirus. The
ability of X. index and L. diadecturus to transmit associated
nepoviruses is clear but controversy surrounds the X. americanurn-group vectors and their associated nepoviruses. The controversy stems from
the reappraisal of the group in 1979 which casts doubt on the identity
of some vectors. The X. americanurn-group vectors are unusual in
that they have only three juvenile stages and apparently lack the high
degree of specificity reported for other nematode-virus associations. Several
unnatural virus-vector associations have also been reported.
Key words: nematode-virus association, Xiphinema, Longidorus,