Paratylenchus hamatus

 

Contents

 

Rev 12/27/2013

Pin Nematode Classification Hosts
Morphology and Anatomy Life Cycle
Return to Paratylenchus Menu Economic Importance Damage
Distribution Management
Return to Tylenchulidae Menu Feeding  References
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Classification:

      Tylenchida
       Tylenchina
        Criconematoidea
         Tylenchulidae
          Paratylenchinae
           Paratylenchus hamatus Thorne and Allen, 1950

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Morphology and Anatomy:

Small plant-parasitic nematodes, 0.3mm long. 

Females:  Gravid female may swell anterior to vulva.

Strong stylet, usually about 36 m.

Ovary single, outstretched.   

Males:  Reduced, with stylet reduced or absent, and probably do not feed. 
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Distribution:

Europe and North America.

Widely distributed in California, but not usually found in cooler grape-growing regions.

Originally described from fig in soil samples taken by E.F. Serr near Planada, California (11 miles west of Merced) and sent to Gerald Thorne in Salt Lake City for diagnosis.  From those samples, Thorne and Allen (1950) described both Xiphinema index and Paratylenchus hamatus.

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Economic Importance:

Paratylenchus hamatus is apparently the most common species of pin nematode in woody perennials of California (Raski, 1975). 

It can occur in abundance in vineyards free of other vegetation, but it is not associated with vine damage except when young grapevines have been planted into very high population levels. 

Highest population levels of this nematode are often measured on the most vigorous vines and its presence appears to slow the build-up of other endo- and ectoparasites (Ferris and McKenry, 1975; Ferris et al., 1976). 

Feeding of large numbers produced shallow, localized lesions on grape roots (Raski and Radewald, 1958).

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Feeding:

       
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Hosts:

Celery, figs, grapes, and peaches in the San Joaquin Valley of California. 

It does not occur on Juglans spp.

For an extensive list of host plant species and their susceptibility, copy the name

Paratylenchus hamatus

select Nemabase and paste the name in the Genus and species box

 

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Life Cycle:

Similar to P. neoamblycephalus, but has a different host range and there are differences in the life cycle of the male. 

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Damage:

Associated with crop decline in figs (Allen), but a positive correlation with vigor has been observed in grape and peach (Ferris and McKenry). McKenry has suggested that P.hamatus may have  an antagonistic or competitive relationship with Criconemoides xenoplax - in recent field experiments (1998-90) soil around peach roots was inoculated with P. hamatus after fumigation, but results were not convincing. 

This nematode also causes damage to celery in North Eastern U.S. and the Netherlands; can also deform carrots. 

Plant weights of mint may be reduced and flowering delayed by P. hamatus infestation in the Yakima Valley of Washington (Inghamm and Merrifield, 1996).

In pot experiments, dry weights of peppermint and scotch spearmint plants 22 weeks after inoculation were reduced 20%-34%.  Infected plants remain succulent longer which renders them susceptible to winter injury (Faulkner, 1964).

In tall fescue grass, tillering was increased but top growth is stunted (Coursen and Jenkins, 1958).

Tops of celery attacked by pin nematodes can become stunted and chlorotic  (Lownsbery et al 1952). Fgs infected by pin nematodes become chlorotic with undersized fruit (Thorne and Allen, 1950).  

 

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Management:

Resistance

For a list of plant species or cultivars (if any) reported to be immune or to have some level of resistance to this nematode species, copy the name

Paratylenchus hamatus

select Nemabase Resistance Search and paste the name in the Genus and species box

 
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References:

Coursen, B.W. and W.R. Jenkins. 1958. Host-parasite relationships of the pin nematode, Paratylenchus projectus on tobacco and tall fescue. Plant Disease Reporter 42:865-872.

Faulkner, L.R. 1964. Pathogenicity and population dynamics of Paratylenchus hamatus on Mentha species. Phytopathology 54:344-348.

Ferris and McKenry, 1975

Ferris et al., 1976 

Ingham, R., Merrifield, K. 1996. A Guide to Nematode Biology and Management in Mint. Integrated Plant Protection Center, Oregon State University, Corvallis. Pub. No. 996. 38 p.

Lowensbry, B.F., E.M. Stoddars and J.W. Lownsbery. 1952. Paratylenchus hamatus pathogenic on celery. Phytopathology 42:651-653.

Raski, 1975

Raski, D.J., Radewald, J.D. 1958. Symptomology of certain ectoparasitic nematodes on roots of Thompson seedless grape. Plant Disease Reporter 42:941-943.

Thorne, G. and M.W. Allen. (1950)  Paratylenchus hamatus n. sp. and Xiphinema index n.sp., two nematodes associated with fig roots, and a note on Paratylenchus anceps.  Proc. Helminth. Soc. Wash 17:27-35.

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For more information about nematodes, Go to Nemaplex Home Page.
Copyright 1999 by Howard Ferris.
Revised: December 27, 2013.