The Virus-Vector and Damage Potential, Morphometrics and Distribution of Paralongidorus maximus

Abstract

Paralongidorus maximus was tested as a vector for 20 viruses. Nine were recovered directly from P. maximus, an indication that they had ingested the virus, but there was no correlation between the ingestion and transmission of these viruses. Raspberry ringspot (English and Scottish strains), arabis mosaic, and strawberry latent ringspot viruses were recovered from the roots of bait plants grown in pots together with virus infected plants and P. rnaximus. Under the experimental conditions, these four viruses may have been transmitted by P. rnaxirnus. Sixteen of these viruses were not transmitted by P. maximus. None were transmitted when P. maximus was extracted between the infector and bait plants. The authors conclude that P. maximus is not likely to be a vector, under field conditions, of any of the presently known nematode-transmitted viruses. A new site is reported for P. maximus in a forest nursery in Angus, Scotland where it was causing considerable damage to 3- and 4-year-old Scots pine (Pinus sylvestris). Morphometrically, this population (which was used in the virus tests) is very similar to populations from Germany and other parts of Britain. Geographical distribution of this species is restricted to western Europe, where i t is widely distributed, and to only three sites in the British Isles. Key Words: Xiphinema diversicaudatum, X. index, X. vuittenezi, Longidorus elongatus, L. macrosoma, Trichodorus spp., root galls, host range, nematode.