Tylenchorhynchus cylindricus

 

Contents

 

Rev 09/20/2008

  Classification Hosts
Morphology and Anatomy Life Cycle
Return to Tylenchorhynchus Menu Economic Importance Damage
Distribution Management
Return to Belonolaimidae Menu Feeding  References
         

 


Classification:

      Tylenchida
       Tylenchina
        Tylenchoidea
         Belonolaimidae
         Telotylenchinae
Tylenchorhynchus cylindricus Cobb, 1913  

    Synonyms:
     Tylenchorhynchus dubius (Reynolds and Evans, 1935

Back to Top

Morphology and Anatomy:

Female: Body straight to slightly arcuate in fixed specimens, tapering at both ends, 0.65-0.99 mm long..  

Annules distinct, coarse, 2 µm wide near midbody.

Lateral fields not areolated, about 1/4 as wide as body behind neck region, marked by 4 incisures.  

Deirids absent; phasmids prominent in both sexes, anterior to middle of tail, in neotype female on 5th and 8th annules behind anus.  

Lip region hemispherical, offset, exhibiting 5 (rarely 4 or 6) annules; labial sclerotization prominent towards basal plate and cheilostom.  

Stylet well developed, with large anteriorly-cupped basal knobs; tapering portion being non-tubular and needle-like in its anterior two-fifths.  

Orifice of dorsal esophageal gland about 2 µm from spear base.  

Median esophageal bulb large, oval; basal bulb elongate-pyriform, with intestine joining its base slightly ventrally; esophago-intestinal valve (cardia) prominent.

Excretory pore near base of isthmus, just behind hemizonid which is 1-2 annules long.  

Sinuous, convoluted canals present in the intestinal region.

Ovaries outstretched with oocytes usually in single row.  

Spermathecae rounded, usually with sperm.   

Tail elongate-conoid, with unstriated, smoothly rounded distal end; intestine not extending into tail cavity.

Male: Body length 0.67-1.0 mm.

Abundant.  

Spicules about 22 µm long, slightly arcuate, with large ventral flanges distally.

Gubernaculum 12 µm long, protrusible, its distal half enlarged with raised sides, proximal end anteriorly curved or crescent-shaped.

[Ref: CIH Descriptions of Plant-parasitic Nematodes, Set 1, No. 7 (1972)]

 

 
 
Back to Top

Distribution:

Arid soils of Western U.S. on desert plants; Cathedral City, California.

 

Back to Top

Economic Importance:

D-rated pests in California. 

 

Back to Top

Feeding:

In cotton, nematodes feed on root tips and possibly along the side on young roots.

Back to Top

Hosts:

Prunus in California; cotton in Arizona; citrus in Florida; pine in New Mexico; crested wheat grass (Agropyron cristatum) and juniper in Utah.

 

Back to Top

Life Cycle:

    

Back to Top

Damage:

In cotton, feeding causes stunting of top growth and reduction in root system in both greenhouse and field trials in Arizona.

Also reported to cause severe damage to crested wheat grass in areas of Utah.  

However, Riffle (1970) demonstrated that growth of seedling Pinus ponderosa parasitized by T. cylindricus under greenhouse conditions for 13 months was not significantly reduced.

 

Back to Top

Management:

 

Back to Top

References:

CIH Descriptions of Plant-parasitic Nematodes, Set 1, No. 7 (1972).

Back to Top

Copyright © 1999 by Howard Ferris.
Revised: September 20, 2008.