An update on the genera Longidorus , Paralongidorus and Xiphinema (Family Longidoridae) in Portugal

The tribe Longidorini within the subfamily Longidorinae (Longidorus spp. and Paralongidorus spp.) and the subfamily Xiphineminae (Xiphinema spp.) are two large nematode groups with about 260 and 230 known species, respectively. They are globally two important groups of ectoparasitic nematodes considered to be major pests because of their activity as vectors of important plant nepovirus, with some species included in the list of quarantine pathogenic organisms in many European countries. Knowledge of the biodiversity and occurrence of this nematode group is a prerequisite for the establishment of sound management strategies and control measures. According to data collected from the databases (such as EPPO, FSTA, and Web of Science) and published in specialised literature, a total of 15 Longidorus, 1 Paralongidorus and 40 Xiphinema species have been recorded as present in Portugal. However, the taxonomic status of some species is controversial, and thus needs to be clarified. A comprehensive review for unravelling the biodiversity and occurrence of nematode species of the genus Longidorus, Paralongidorus and Xiphinema in Portugal is herein provided. This review includes an updated checklist of species with information on the localities, host plants and geographical distribution. Additionally, maps on the species distributions of Longidorinae and Xiphineminae nematodes present in Continental Portugal and the Portuguese Macaronesian islands are provided, as well as unpublished data on authors and comments on the current taxonomic status. Finally, new insights and directions for future research on Longidoridae in Portugal are presented.

Review of the genus Bursaphelenchus Fuchs, 1937 (Nematoda, Aphelenchida) with some conclusions on the host-parasite and vector-parasite evolution.

INTRODUCTION AND GOALS: Genus Bursaphelenchus includes several pests of the world importance for the rural economy, the most dangerous are the Bursaphelenchus xylophilus (the pinewood nematode caused decline of the pine trees in south Asia and in one spot area in Europe, Portugal, Peninsula de Setubal) and the Bursaphelenchus cocophilus, causing the decline of coco-palm plantations in Carribean and Latin American regions. The peculiarity of the host-parasite association of the genus that the nematode life cycle includes three trophic components: plant (mostly a tree), insect vector and a fungus. Goals of the presentation is to list all species of the world fauna and all efficient diagnostic characters, then create the identification tool and analyze the similarity of species and possible ways and causes of the host-parasite evolution of the group. RESULTS: Complete list of species with synonymy and a catalogue of all efficient diagnostic characters with their states, selected from papers of the most experienced taxonomists of the genus, are given for the genus Bursaphelenchus. List of known records of Bursaphelenchus species with names of natural vectors and plants and their families is given (for world pests the most important groups of trees and insects are listed). The tabular, traditional and computer-aided keys are presented. Dendrograms of species relationships (UPGMA, standard distance: mean character difference) based on all efficient taxonomic characters and separately on the spicule characters only, are given. Discussion whether the species groups are natural or purely diagnostic ones is based on the relationships dendrograms and the vector and associated plant ranges of Bursaphelenchus species; the xylophilus species group (B. xylophilus, B. abruptus, B. baujardi, B. conicaudatus, B. eroshenkii, B. fraudulentus, B. kolymensis, B. luxuriosae; B. mucronatus), the hunti group (B. hunti, B. seani, B. kevini and B. fungivorus) are probably the natural ones. CONCLUSIONS: The parasitic nematode association includes three trophic components: plant, insect vector and fungus. The initial insect-plant complex Scolytidae-Pinaceae is changeable and only in rare occasions the change of the preferred vector to Cerambycidae (the xylophilus group), Hymenoptera (the hunti group) led to formation of the natural species-groups. From the analysis it is clear that although the vector range is changeable it is comparatively more important for the evolution of the genus Bursaphelenchus than associations with plants at the family level. Data on the fungi species (3rd component in natural Bursaphelenchus associations) are insufficient for the detailed comparative analysis.