The demonstration by Hewitt, Raski and Goheen from UC Davis (1958) that X. index transmitted fanleaf virus of grapevine was the first experimental proof of the role of nematodes in virus transmission.
Narrow host range; grape, fig, apple, rose, mulberry and woody perennials.
Closely related to that of its most important host, grapevine: Argentina, Australia, Chile, France, Germany, Greece, Hungary, Iran, Iraq, Italy, North Africa, Portugal, South Africa, Spain, Turkey and USA. Generally found in Northern California, but sporadically as far south as Kern County.
Migratory root ectoparasite; all stages feed at root tips. Reproduction is by meiotic parthenogenesis. Males are very rare. Reported in California as requiring 22-27 days at 24 C. Reported in Israel as 7-9 months at 20 to 23 C and 3-5 months at 28 C.
Attacked roots show necrosis, lack of lateral roots, terminal swelling or galling, cellular hypertrophy and multinucleate condition of cortical cells near the feeding sites. A 38 to 65% reduction in root weight has been demonstrated experimentally. The nematode transmits grapevine fanleaf virus. The virus is intimately associated with the esophageal lining. It is acquired in 5-15 minutes of feeding, and persists for up to 9 months when nematode is not feeding. Virus is lost at molt. Grapevine fanleaf virus causes reduced vigor, lack of fruit set, and reduced yield. Distinctive leaf symptoms consisting of vein banding and misshapen leaves are typically present in the fall.
Remove virus infected vines and initiate 5-10 year rotation for roots to die followed by preplant fumigation. The organophosphate Nemacur (phenamiphos), the carbamate Furadan (carbofuran) and sodium tetraathiocarbonate (Enzone) are registered for postplant treatment. Rootstocks - hybrids of Vitis vinifera and V. rotundifolia were first developed by Olmo in late 1940s. Two rootstocks O39-16 and O43-43 were recently released by the University of California.
Approximately 50% yield reductions occur in vines infested with grapevine fanleaf virus. It is thought that this nematode was imported into California from France on infested grape rootstoccks.
Xiphinema - Somewhat similar to Longidorus but the amphid ampertures are wide slits and the amphid pouch is a short funnel shape. The long odontostyle is forked at its base where it joins the odontophore; the latter is strongly developed with prominent basal flanges. The guiding ring is double and around the posterior half of the odontostyle. Vulva usually median with paired opposed gonads; occasionally more anterior with a single posterior gonad, the anterior branch reduced but varying in development. Gonad structure variable often with characteristic features for a particular species. Tail shape varies from short, rounded, to elongate conoid, occasionally filiform.