Longidorus   

  

Contents

  

Rev 03/23/2007

Needle nematodes Classification Hosts
Morphology and Anatomy Life Cycle

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 Economic Importance Damage
Distribution Management
Return to Longidoridae Menu Feeding  References
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Classification:

      Adenophorea
       Dorylaimida
        Dorylaimina
         Dorylaimoidea
          Longidoridae
           Longidorinae                           
            Longidorus (Filip'ev, 1934) 

  
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Morphology and Anatomy:

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Needle nematodes, like dagger nematodes, are very large, ranging in length from 2 to 8 mm. 

In needle nematodes, odontostyle is long, the total length of odontostyle and odontophore is about 150 µm. 

The odontostyle is connected to the lining of cheilostome by a cuticular membrane that becomes variously folded, with refractory qualities - the "guiding ring." In Longidorus, the guiding ring is located within two lip-widths of the anterior portion of the nematode. 

Opening of amphid is pore-like in Longidorus and slit-like in Paralongidorus.

Females of Longidorus have two ovaries that are opposed and reflexed.

 

 

      

 
Characters used for identification of Longidorus (Franco Lamberti):
  1. Body size (three groups):
    a. Small 2-4 mm.
    b. Medium 5-8 mm.
    c. Large 8-15 mm.
  2. Shape of lip region:
    a. Expanded lip region, separated from body
    b. Cylindrical shape continuous with body or slight constriction
    c. Continuous, but lip region acute or pointed 
  3. Shape of tail:
    a. bluntly rounded
    b. conoid-rounded or pointed terminus
    c. elongated tail
  4. Length of odontostyle (10% variation within a population)
  5. Position of guiding ring
  6. Shape of amphidial pouch
  7. Cobb formula measurements.
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Distribution:

Worldwide, usually moist environments.

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Economic Importance:

 

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Feeding:

 

 

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Hosts:

At least seven species of Longidorus are reported from grape vineyards throughout the world. They include L. attenuatus Hooper, L. diadecturus Eveleigh and Allen, L. elongatus Thorne and Swanger, L. iranicus Sturhan and Barooti, L. macrosoma Hooper, L. protae Lamberti and Bleve-Zacheo, and L. sylphus Thorne. Relatively little critical biological and ecological data have been developed for this genus on grapes. 

 

 
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Life Cycle:

The first juvenile stage emerges from the egg and passes through three more juvenile stages. 

Males are rare in most species and presumably unnecessary for reproduction in those cases (Raski, 1988), although amphimictic populations do occur (Ye and Robbins, 2004).

 

 

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Damage:

Severe stunting of  loblolly pine seedlings at a south Georgia nursery.  Nematode populations increased in containers with slash, loblolly, and longleaf pine seedlings. The Longidorus sp. significantly reduced the dry root weights of slash (P = 0.008) and loblolly (P = 0.047) but not longleaf (P = 0.095) pine compared with controls (Fraedrich et al., 2003).

 

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Management:

As and example, the Longidorus sp. damaging to loblolly pines decreased on nutsedge and small grains.  Periodic rotation from pine production to grow cover crops consisting of small grains important management practice this species (Fraedrich et al., 2003).

 

 

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References:

Fraedrich SW, Cram MM, Handoo ZA 2003. Suitability of southern pines, other selected crops, and nutsedge to a Longidorus sp associated with stunting of loblolly pine seedlings.  Plant Disease 87:1129-1132.

Ye WM, Robbins RT. 2004. Longidorus biformis n. sp and L. glycines n. sp (Nematoda : Longidoridae): Two amphimictic species from Arkansas. Journal of Nematology 36:1-13.

 

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Copyright © 1999 by Howard Ferris.
Revised: March 23, 2007.