COST Action 819: Entomopathogenic nematodes, supercedes Action 812: Cold active lines of insect parasitic nematodes in Agriculture and Biotechnology. It functions in the field of Agriculture and Biotechnology and began in July 1994 and will end in May, 1999. The main objective is to combine interrelated European expertise to increase the use of entomopathogenic nematodes (EPNs) in integrated pest management and to reduce the need for chemical control. Coordination of the Action is the responsibility of a management committee in accordance with a Memorandum of Understanding, which has been signed by representatives of 17 countries: Austria, Belgium, Czech Republic, Finland, France, Germany, Hungary, Ireland, Italy, The Netherlands, Norway, Poland, Portugal, Spain, Sweden, Switzerland and the UK. A research institute in Israel is also participating. Over 40 research institutions and 10 commercial companies participate in Action 819. The EU funding meets the costs related to coordination including the scientific secretariat, workshops, management committee and working group meetings, publications, short term scientific missions and evaluations.

The evolutionary relationships of 82 species of tylenchid and aphelenchid nematodes were evaluated by use of sequence data of the D2 and D3 expansion fragments of the 28S ribosomal RNA genes. Nine automatic and one culled sequence alignments were analysed using maximum parsimony and Bayesian inference approaches. The molecular data sets showed that the order Tylenchida comprises lineages that largely correspond to two suborders, Hoplolaimina and Criconematina, and other taxonomic divisions as proposed by Siddiqi (2000). Several significant results also derived from our study include: i) the basal position of groups that include entomoparasitic nematodes within tylenchid trees; ii) paraphyly of the superfamily Dolichodoroidea sensu Siddiqi (2000); iii) evidence for a Pratylenchus, Hirschmanniella and Meloidogyne clade; and iv) lack of support for widely held traditional placement of Radopholus within Pratylenchidae and placement of this genus within Hoplolaimidae or Heteroderidae. Congruence and incongruence of molecular phylogeny and traditional classifications and morphological-based hypotheses of phylogeny of tylenchids are discussed.The order Tylenchida Thorne, 1949 includes the largest and most economically important group of plant-parasitic nematodes. As plant parasites they have diverged to exploit all plant parts including foliage, flowers and seeds, but mostly they attack roots. The order also includes mycophagous species, and a large group parasitises the haemocoel of insects and mites. Several classifications and phylogenies have been proposed for ty-

The stem nematode Ditylenchus dipsaci is of great economic importance worldwide as a parasite of agricultural crops and horticultural plants. The internal transcribed spacer (ITS) of rDNA from 23 populations of the D. dipsaci complex from various host plants were amplified and sequenced. Seven previously studied populations were also included in the study. The phylogenetic analysis of the full ITS and ITS2 sequence alignments using minimum evolution, maximum parsimony, and Bayesian inference under the complex model of DNA evolution revealed trees with two main clades: (i) D. dipsaci sensu stricto with diploid chromosome numbers and comprising most isolates from agricultural, ornamental, and several wild plants, and (ii) Ditylenchus spp. with polyploid chromosome numbers, reproductively isolated from diploid populations, and subdivided into six subclades ("giant race" from Vicia faba, Ditylenchus species parasitizing various Asteraceae, and a Ditylenchus sp. from Plantago maritima). Using the energy minimization approach and comparative sequence analysis, it has been found that the secondary structure of ditylenchid ITS2 is organized in three main domains. The importance of knowledge on the RNA structure for phylogenetic analysis is discussed. Conventional polymerase chain reaction (PCR) and real-time PCR with SYBR green dye I with a species specific primer have been developed for detection and quantification of D. dipsaci sensu stricto Validation tests revealed a rather high correlation between real numbers of fourth-stage juveniles of the stem nematodes in a sample and expected numbers detected by real-time PCR. Problems of accuracy of quantification are discussed.

No abstract

Species of the Heterodera avenae complex, including populations of H. arenaria, H. aucklandica, H. australis, H. avenae, H. lipjevi, H. mani, H. pratensis and H. ustinovi, obtained from different regions of the world were analysed with PCR-RFLP and sequencing of the ITS-rDNA, RAPD and light microscopy. Phylogenetic relationships between species and populations of the H. avenae complex as inferred from analyses of 70 sequences of the ITS region and of 237 RAPD markers revealed that the cereal cyst nematode H. avenae is a paraphyletic taxon. The taxonomic status of the Australian cereal cyst nematode H. australis based on sequences of the ITS-rDNA and RAPD data is con rmed. Morphometrical and ITS-rDNA sequence analyses revealed that the Chinese cereal cyst nematode is different from other H. avenae populations infecting cereals and is related to H. pratensis. Bidera riparia Kazachenko, 1993 is transferred to the genus Heterodera as H. riparia (Kazachenko, 1993) comb. n. As a consequence, H. riparia Subbotin, Sturhan, Waeyenberge & Moens, 1997 becomes a junior secondary homonym and is renamed as H. ripae nom. nov. Morphological, morphometrical characters and RFLP pro les for identi cation of the nine species presently placed in the H. avenae species complex are given.