Systernatics of the Trichodoridae (Nematoda) with keys to their species

Keys are given for the identification of species in the Trichodoridae, partly based on the keys of Loof (1975) and Siddiqi (1974). Recent additions are included and for al1 species a drawing is given of the structure referred to in the key. The genus Paratrichodorus and the diagnostic value of the subgenera Paratrichodorus, Atlantadorus and Nanidorus are discussed. R É S U M B Systématique des Trichodoridae (Nematoda) et clés de détermination des espèces L’auteur propose de nouvelles clés de détermination des espèces de Trichodoridae fondées sur les clés de Loof (1975) et de Siddiqi (1974), et tenant compte des données les plus récentes. Des illustrations sont fournies pour les caractères les plus importants de chaque espèce. Le genre Paratrichodorus et, la,valeur des sous-genres Paratricho-dorus, Atlantadorus et Nanidorus sont discutés. The Trichodoridae are economically, a very important group of nematodes as ectoparasites on the roots of many crop plants and as vectors of tobacco rattle virus and pea early browning virus. Despite the ease with which nematodes can acquire viruses from plants there are rela-tively few vectors. Of some 35 species of Tricho-doridae, a t least eleven transmit tobra-viruses (Hooper, 1973), so identification to species level may be very important. During my study on Trichodoridae 1 came across several inadequacies in available descrip-tions and keys; these changes, together with recent additions made i t necessary t o modify the Beys of Loof (1975) and Siddiqi (1974). For al1 the species 1 have included a drawing of the structure referred to in the key