Longidorus   

 

Contents

 

Rev 09/13/2023

Needle nematodes Classification Hosts
Morphology and Anatomy Life Cycle

Return to Longidorus Menu

Economic Importance Damage
Distribution Management
Return to Longidoridae Menu Feeding  References
    Go to Nemaplex Main Menu   Go to Dictionary of Terminology

 

Classification:

      Enoplea
       Dorylaimida
        Dorylaimina
         Dorylaimoidea
          Longidoridae
           Longidorinae                           
           
Longidorus Micoletzky, 1922

  Type species of the genus: Longidorus elongatus  (de Man, 1876) Micoletzky, 1922
Back to Top

 Morphology and Anatomy:

As of 2017, there were more than 168 described species (Xu et al., 2017).

.

 

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 �m. 

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 in some species  and at mid-odontostyle in others.

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

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

 

The distance of the guiding ring from anterior end has been used as an important morphological character for species identification within Longidorus  (Xu et al., 2017).

      

 
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.
Body size range for the species of this genus in the database - Click:
Back to Top

Distribution:

Worldwide, usually moist environments.  Although widely distributed they are sometimes rather difficult to find!

Back to Top

Economic Importance:

D-rated pest in California Nematode Pest Rating System, except for L. africanus which is C-rated

Back to Top.

Feeding:

  Generally considered root tip feeders.

 

Back to Top

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. 
For an extensive host range list for this genus, click
Back to Top

Life Cycle:

For Ecophysiological Parameters for this genus, click 
 

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).

 

 

Back to Top

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).

Besides their direct damage to plant roots, about seven species transmit pathogenic nepoviruses to higher plants.

 

Back to Top

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).

 

 

Back to Top

References:

Cid del Prado Vera, I., Subbotin, S.A., Decraemer, W. 2021. Descriptions of Trichodorus lownsberyi sp. n., Nanidorus minor (Colbran, 1956) Siddiqi, 1974 (Nematoda: Trichodoridae) and Longidorus quercus sp. n. (Nematoda: Longidoridae) from Mexico. Nematology, 23:1023-1037. doi: https://doi.org/10.1163/15685411-bja10092

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.

Subbotin, S.A., Rogozhin, E.A. & Chizhov, V.N. 2013. Molecular characterisation and diagnostics of some Longidorus species (Nematoda: Longidoridae) from Russia and other countries using rRNA genes. European Journal of Plant Pathology 138, 377-390. DOI: 10.1007/s10658-013-0338-9

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.

Xu, Y., K. Guo, W. Ye, J. Wang, J. Zheng and Z. Zhao. 2017. Morphological and molecular characterisation of Longidorus juglans sp. nov. and a sister species L. fangi Xu & Cheng, 1991 (Nematoda: Longidoridae) from China. Nematology 19:951-970.

 

Back to Top

Copyright © 1999 by Howard Ferris.
Revised: September 13, 2023.