Hoplolaimus galeatus

 

Contents

 

Rev 12/27/2013

Lance Nematode  Classification Hosts
Morphology and Anatomy Life Cycle
Return to Hoplolaimus Menu Economic Importance Damage
Distribution Management
Return to Hoplolaimidae Menu Feeding  References
    Go to Nemaplex Home Page    

  
   


Classification:

        Tylenchina
        Tylenchoidea
         Hoplolaimidae
          Hoplolaiminae
     Hoplolaimus galeatus (Cobb, 1913) Thorne, 1935 

    Synonyms:
      Nemonchus galeatus Cobb, 1913
      Hoplolaimus coronatus Cobb, 1923
      Hoplolaimus tylenchiformis Andrássy, 1958
Back to Top

Morphology and Anatomy:


A-F = female; G,H = male

Female: Cephalic region offset usually with 5 annules, forming an low cone generally with flattened sides.  Basal annule with 32-36 longitudinal striations seen in face view.  Cephalic framework yellowish, massive, differing in details between sexes.  

Stylet knobs with anteriorly directed processes.  

Esophageal glands with 3 nuclei.  

Hemizonid about 2 annules long, situated just anterior to excretory pore which is near level of esophago-intestinal valve.  

Hemizonion about 5 annules posterior to pore, caudalid about 8 annules anterior to anus.  

Ovaries outstretched, spermathecae round to oval.  Epiptygma single or double, usually conspicuous.  

Intestine overlapping rectum and usually extending into tail. 

Tail rounded, with 10-16 annules.  

Lateral field with 4 incisures, usually areolated, but occasionally only partly so.

Male: Cephalic region higher and less conoid than female, hemispherical with convex sides.  Similar to female in other respects.

Spicules 40-52 µm long, slightly arcuate. 

Gubernaculum with titillae; gubernaculum may be bent distally in some specimens.  


[Ref: CIH Descriptions of Plant-parasitic Nematodes, Set 2, No. 24 (1973)]

 

 

 
Back to Top

Distribution:

Widely distributed in the U.S., especially on woody or graminaceous plants.

 

Back to Top

Economic Importance:

 

 

Back to Top

Feeding:

Primarily endoparasites.  

Feeding occurs in root cortex of both lateral and mycorrhizal short roots, where the nematode causes considerable damage in its migration parallel to the long axis.  

In root cortex of cotton, nematode prefers phloem.  

Damage to vascular tissue is more extensive than to cortex, abnormal division of phloem parenchyma or tylose production in the xylem sometimes occurring in response.

Back to Top

Hosts:

Cotton, pine, oak, sycamore, wheat, carnation, cranberry, grasses, sugarcane, clover, vetch, grape, peach; highly pathogenic on turfgrass in Florida.

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

Hoplolaimus galeatus

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

 

 

Back to Top

Life Cycle:

Few aspects of biology and life-history have been investigated.  

Population increase has been studied on cotton (Krusberg & Sasser, 1956), cranberry (Bird & Jenkins, 1964), and bermuda grass (Di Edwardo, 1963).

Population dynamics has been investigated in other grasses and legumes (McGlohon et al., 1961), red pine seedbeds following chemical treatment (Sutherland & Adams, 1966), and cotton following Paspalum notatum (Rodriguez-Kabana & Pearson, 1972).

Back to Top

Damage:

Hoplolaimus galeatus damage (right) to roots of St. Augustine's grass (University of Florida photograph).

Note loss of feeder roots.

Infected cotton plants grown under conditions of limited moisture are susceptible to stunting, yellowing, and defoliation.  

In cotton, the nematode feeds primarily endoparasitically causing considerable cortical damage during penetration.  

Infected pine seedlings are devoid of healthy lateral roots and mycorrhizae.  High nematode population levels can reduce root weight of Pinus clausa by 54% (Ruehle, 1972).  Pine seedlings can suffer 50% mortality.  

In sycamore, high inoculum levels caused extensive root necrosis and marked decrease in fresh weight.  

After 75 days, peach seedlings growing in soil infected with Fusarium oxysporum and H.  galeatus were markedly smaller than controls or combinations of fungus and other nematode species tested (Wehunt & Weaver, 1972).

Hoplolaimus galeatus damage on St. Augustine's grass (University of Florida photograph)

Hoplolaimus galeatus damage on Bermuda grass (University of Florida photograph)

 

Back to Top

Management:

Fumigants - pre-plant treatment of plant rows with 1,3-Dichloropropene (1,3-D) produced taller pine trees after 5 years than trees growing in untreated rows.  

Treatment with Nemacur gave 3 months' field control on bermuda grass.  

Population can be reduced, but not eliminated, if infested soils are left fallow for 16 months.

Host Plant Resistance, Non-hosts and Crop Rotation alternatives:

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

Hoplolaimus galeatus

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

 

Back to Top

References:

CIH Descriptions of Plant-parasitic Nematodes, Set 2, No. 24 (1973)]

H. Ferris

Back to Top

Copyright © 1999 by Howard Ferris.
Revised: December 27, 2013.