''Xiphinema'' is a genus of
ectoparasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...
root
nematodes commonly known as dagger nematodes.
[Whitehead, A.G. 1998. Plant Nematode Control] The genus is of economic importance on grape, strawberry, hops and a few other crops. Major species include ''X.americanum, X.diversicaudatum, X.index, X.italiae'' and ''X.pachtaicum''.
[Evans, K., Trudgill, D.L., Webster, J.M. 1998. Plant Parasitic Nematodes in Temperate Agriculture.] They can be easily recognized by their long bodies and stylets which are long enough to reach the vascular tissue of plants.
[''Xiphinema'']
at Nemaplex, University of California
The University of California (UC) is a public land-grant research university system in the U.S. state of California. The system is composed of the campuses at Berkeley, Davis, Irvine, Los Angeles, Merced, Riverside, San Diego, San Franci ...
Different members of the genus have been shown to induce moderate to large amounts of root damage through root penetration, which in some species results in the formation of
galls.
[ They are of agricultural concern because they are vectors of ]nepovirus
''Nepovirus'' is a genus of viruses in the order ''Picornavirales'', in the family ''Secoviridae'', in the subfamily ''Comovirinae''. Plants serve as natural hosts. There are 40 species in this genus. Nepoviruses, unlike the other two genera (' ...
es, transferring them during feeding.[Taylor, C.E., Robertson, W.M., 1970. Sites of Virus Retention in the Alimentary Tract of the Nematode Vectors, ''Xiphinema diversicaudatum'' (Micol.) and ''X.index'' (Thorne and Allen), Annals of Applied Biology (1970),66, 375-380)] Efforts to study these nematodes in more detail have proved problematic in some species due to difficulties in maintaining populations in a greenhouse environment.[
]
Morphology
''Xiphinema'' are large nematodes, with an adult length between 1.5mm – 5.0mm.[ They have a long protrusible ]