Ogma    

  

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Rev 12/18/2023

Classification Hosts
Morphology and Anatomy Life Cycle

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 Economic Importance Damage
Distribution Management
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Classification:

  Tylenchida
       Tylenchina
        Criconematoidea
         Criconematidae
          Criconematinae

            Ogma Southern, 1914

Andrassy (1979) observed that the genus Criconema, the type genus of Criconematidae, was based on the description of Criconema guernei which he considered species dubia because it was an inadequate description of a juvenile nematode. Thus the genus name Criconema is considered invalid and the species are transferred to Ogma Southern, 1914. 

    Synonyms:
      Criconema (Variasquamata) (Mehta & Raski, 1971)
      Variasquamata (Mehta & Raski, 1971)     
      Crossonema (Mehta & Raski, 1971)        
      Crossonema (Crossonema) (Mehta & Raski, 1971)
      Crossonema (Seriespinula) (Mehta & Raski, 1971)
      Seriespinula (Mehta & Raski, 1971)    
      Neolobocriconema (Mehta & Raski, 1971)  
      Croserinema (Khan, Chawla & Saha, 1976)
      Neocrossonema (Ebsary, 1981)    
      Pseudocriconema (Minigawa, 1984)
      Syro (Orton Williams, 1985)          
      Ogma (Homogma) (Siddiqi, 1986)
      Paralobocriconema (Minigawa, 1986)
      Macrocriconema (Minigawa, 1986)
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Morphology and Anatomy:

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Female: Body small to rather large (0.27 to 0.86 mm), short, plump, has 44 to 90 annules with various cuticular ornamentations over the entire body (simple scales or rounded or pointed appendages arranged in 8 to 18 longitudinal rows, each annule bearing 8 palmate lobes with 2 to 6 finger-shaped spines arranged alternating with spines on adjacent rows; single spines may appear scattered on annules; scales or spines arranged in 9 to 20 (rarely 27) longitudinal lines, many bi- or multi-lobed (2 to 7 at tip), or with continuous fringe or scales or spines, bluntly rounded, unipointed, not arranged in rows, 24 to 90 in number on one annule at midbody.  Genus has two labial annules (exceptionally one) rather well set off from next succeeding annule; with or without ornamentation; first usually wider than second, but it may be about equal in width; submedian lobes absent or more or less developed when present.  

Stylet is 48 to 130 µm long.  

Vulva closed or open, on 3rd to 19th annule from terminus; anterior lip seldom longer than posterior one.  

Tail conoid-pointed to bluntly rounded.
Male: Three or four lines in lateral field.

Caudal alae rudimentary or lacking.

Juveniles: Scales in 8 to 18 longitudinal rows or rarely alternating with adjacent annules

[Ref: Raski & Luc (1987), and H. Ferris.] 
Body size range for the species of this genus in the database - Click:
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Distribution:

 
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Economic Importance:

D-rated pests in California.

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Feeding:

 

 

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Hosts:

 
For an extensive host range list for this genus, click
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Life Cycle:

For Ecophysiological Parameters for this genus, click 
 
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Damage:

 

 

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Management:

 

 

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References:

Andrassy, I. 2007. Free-living Nematodes of Hungary, II (Nematoda errantia). Pedozoologica Hungarica 3. Hungarian Natural History Museum, Budapest, Hungary. 496p.

Andrassy, I. 1979. Revision of the subfamily Criconematinae Taylor 1936 (Nematoda). Opuscula Zoologica 16:11-57.

Bongers, T. 1988. De Nematoden van Nederland, Pirola, Schoorl. Utrecht. 408p.

Raski, D.J. and Luc, M. 1987. A reappraisal of Tylenchina (Nematoda) 10. The superfamily Criconematoidea Taylor, 1936. Revue de Nematologie 10:409-444.

Van den Berg, E. 1993. A first list of plant-parasitic nematodes from the Wilderness National Park, with a description of Ogma sekgwaum spec. nov. Koedoe 36:63-76.

H. Ferris.

 

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Copyright © 1999 by Howard Ferris.
Revised: December 18, 2023.