Volume 4, Part 1 (1996)
Howardula phyllotretae (Tylenchida: Allantonematidae) - parasite of Phyllotreta
flea beetles (Coleoptera: Chrysomelidae), 1-6.
Loof. Dichotomous and polytomous identification keys for females
of the genera Prodorylaimus Andrassy, 1959 and
Laimydorus Siddiqi, 1969 (Nematoda: Dorylaimoidea), 7-28.
H.J. Rumpenhorst and D. Sturhan. Morphological and electrophoretic
studies on populations of the Heterodera avenae complex from the
former USSR, 29-38.
The potato cyst nematode, Globodera rostochiensis, in the Ukraine, 39-42.
V.V. Malakhov and V.V. Yushin. Comparative morphology and evolution
of the cuticle in marine nematodes, 43-50.
Phylogeny of the Longidoridae, 51-60.
The metamorphosis of traditional into advanced phylogenetic systematics and
its impact on nematode systematics, 61-70.
Nematode ecology, 71-76.
Abstracts of papers presented at the First English Language International
Symposium of the Russian Society of Nematologists (St. Petersburg, 23rd-30th
September 1995), 77-104.
- Book Review, 105.
Howardula phyllotretae (Tylenchida: Allantonematidae)
- parasite of Phyllotreta flea beetles (Coleoptera: Chrysomelidae)
A description of the free-living stages of entomogenous nernatode H.
phyllotretae Oldham, 1933 is given for the first time. Data are presented
on the prevalence and intensity of flea beetle infestation with these nematodes.
Parasite induced changes in host reproductive system are described. An
identification key for Howardula species is presented.
Key words: Tylenchida, Allantonematidae, Howardula
phyllotretae, morphology, host-parasite relationships, key for Howardula.
Dichotomous and polytomous identification keys for
females of the genera Prodorylaimus Andrassy, 1959 and Laimydorus
Dichotomous and polytomous identification keys are given for females
of species in the genera ProdoryIaimus and Laimydorus. It
is necessasy to give combined keys for these two genera, because female
specimens do not show any characters to indicate to which genus they belong.
The genera Prodoiylaimium Andrassy, 1969 and Apodorylaimus
Andrassy, 1988 are considered identical with Prodorylaimus, and,
the genus Calodorylaimus Andrassy, 1969 identical with Laimydorus.
Because Idiodorylaimus Andrassy, 1969 is very similar to Laimydorus,
and because occasionally the distinguishing character (transverse cuticular
striation) is difficult to observe, the species of Idiodorylaimus
are included except one which possesses longitudinal cuticular ridges.
As the morphology of females of the genus Afrodorylaimus Andrassy,
1964 does not differ from that of Laimydorus and
Prodorylaimus, Afrodorylaimus is also included.
Key words: identification, Laimydorus, Prodorylaimus,
Apodorylaimus, Calodorylaimus, Prodorylaimium, Idiodorylaimus, Afrodorylaimus.
S.A., Rumpenhorst, H.J. and Sturhan, D.
Morphological and electrophoretic studies on populations
of the Heterodera avenae complex from the former USSR
Isoelectric focusing of protein extracts of ten Heterodera 'avenae'
populations from Russia, Ukraine and Tadzhikistan revealed a uniform protein
pattern for all populations, except for one population from Putilovo, Leningrad
region. A comparison with populations of H. avenae, H. mani and
an obviously undescribed species of the H. avenae group from Germany
showed that the population group from the former USSR is distinct from
avenae and the other populations included in the study. Only the Putilovo
population showed a protein pattern similar to the populations of the undescribed
species. Morphological and morphometrical studies on the populations from
the former USSR supported the results of the electrophoretic studies and
the distinction of all populations from the H. avenae populations
from Germany. The population from Tadzhikistan closely agrees with the orinnal description of H. filipjevi and all populations
from the former USSR are considered as representatives of this species,
except the Putilovo population which proved to represent another species
within the H. avenae (s. str.) complex.
Key words: Heterodera avenae, H. filipjevi, electrophoresis,
morphology, measurements, distribution, Russia, Ukraine, Tadzhikistan,
The potato cyst nematode, Globodera rostochiensis,
in the Ukraine
It is estimated that G. rostochiensis, first recorded in the
Ukraine in the early 1960s, has spread and now occurs in an area of 6000
hectares in 12 of the 14 regions in which potato production is a major
arable enterprise. Chemical control of the nematode has proved to be ineffective
and several regions with the largest nematode populations. Several potato
cultivars have been bred in the Ukraine which are resistant and/or tolerant
to G. rostochiensis and are effective at reducing the crop damage caused
by the nematode.
Key words: control, distribution, Globodera rostochiensis,
pathotype, resistance, tolerance.
A.V., Malakhov, V.V. and Yushin, V.V.
Comparative morphology and evolution of the cuticle
in marine nematodes
In embryos of some species of marine nematodes the somatic cuticle
is formed with the assistance of short microvilli which disappear in subsequent
developmental stages. The most primitive cuticle type in free-living species
is a simple four-layered construction where mesocuticle is underdeveloped
and may be poorly demarcated from the endocuticle. This cuticle type is
broadly distributed among different marine nematode families and may be
a transient stage in the ontogenesis of a complex cuticle. With progressive
evolutionary development the cuticle becomes more complex as a result of
additional stratification of the exo- and mesocuticles. Structurally the
most complex cuticle, with stratified mesocuticle, is observed in large
and active species. Other evolutionary trends appear to be correlated with
particular specializations where the exocuticular zone predominates (e.g.
Halalaimus, certain Chromadoridae), secondary simplification (some
Ceramonematidae - Pselionema), or development of secretory deposits
(Desmoscolecidae). A few marine nematodes, because of their immobility,
retain the embryonal cuticule-type through to, and including, the adult
Key words: cuticle, marine nematodes, ultrastructure,
comparative morphology, evolutionary morphology, transformation rows.
Phylogeny of the Longidoridae
The longidorid ancestor is reconstructed on the basis of primitive
characters encountered in extant species of the family. The present distribution
and morphology of the various genera are related to the geological history
of the continents to trace the area of origin as well as the evolution
within the family. The cladogram of the Longidoridae is amended and two
possible classifications are proposed on the basis of the cladogram.
Key words: distribution, evolution, geological history,
Gondwanaland, Longidoroides, Longidorus, Oceania, Paralongidorus,
Paraxiphidorus, Xiphidorus, Xiphinema.
The metamorphosis of traditional into advanced phylogenetic
systematics and its impact on nematode systematics
Phylogenetic systematics as proposed by Hennig has become very successlul.
However, since its beginning, it has suffered from a fundamental mistake
which appears inconsequential at first glance: the relative concepts of
synapomorphy and symplesiomorphy were employed as if they were absolute.
Closer inspection reveals the full impact of this mistake which has resulted
in the exclusion of "symplesiomorphies", once recognized as such, from
further analysis, and to transforming phylogenetic systematics into a form
of nonphylogenetic systematics named cladistics which is not based in any
way on the theory of evolution. By re-establishing the relativity of the
concepts analysed, advanced phylogenetic systematics is achieved in which,
by employing the so-called loss tracing method and knowledge ultimately
inferred from the theory of evolution, traditional "symplesiomorphies",
become exploitable for recognizing holophyletic species sets. Therefore,
advanced phylogenetic systematics is superior to traditional phylogenetic
systematics and cladistics. A nematological example is provided which demonstrates
the new approach.
Key words: phylogenetic systematics, cladistics, parsimony,
outgroup analysis, loss tracing method, theory of evolution, nematodes,
Plant and soil nematodes belong to the animal kingdom and thus the
continued existence of each species requires that individuals obtain sufficient
food to meet the requirements of the basic energy budget (consumption =
respiration + wastes + body growth + reproduction). To fulfil these requirements
nematodes must interact with other organisms in, and other components of;
their environment. These interactions can be included under the following
headings: food; temperature and moisture regimes; physical substrate; biological
competition; developmental stage; assemblage (reflecting the total environment);
soil or substrate processes. Although novel techniques enable new information
to be obtained, it requires a problem to be defined to focus scientific
enquiry. Currently, it appears that the dominant, unifying problem to be
addressed in nernatode ecology is that of the duration of nematode activity
as temperature and moisture regimes fluctuate in real substrates. Integrating
such knowledge into conceptual or mathematical models would help to provide an understanding
of the migration of plant-pathogenic nematode species to roots, the dispersal
and survival of entomophilic nematodes, the relation between activity and
biodiversity, the importance of micro-sites, and the proportion of time
microbial-feeding nematodes actively contribute to soil processes.
Key words: nematode, development, ecology, soil, temperature,