NEMATOLOGY 100
Laboratory Exercise 7
Rev. 10/16/2008

Purpose:  Ectoparasitic nematodes: Orders Dorylaimida and Triplonchida

Morphology, anatomy, feeding habits:
        Longidoridae (Dorylaimoidea, Dorylaimina, Dorylaimida)
        Trichodoridae (Diphtherophoroidea, Diphtherophorina, Triplonchida)

     1.   Slide presentation of characteristics and virus transmission.

     2.   Hand-pick live adults of

          a)   Trichodorus sp. from shrubs, Davis.
                    b)   Trichodorus sp. from lettuce, Salinas.
          c)   Xiphinema index from grape.
d)   Xiphinema americanum from grape, Lodi.

         Draw the nematodes, observing the following characteristic features:

          a)   spear length and morphology.
          b)   esophagus type and anatomy, nature of postcorpus
               interface with intestine.
          c)   male and female reproductive structures.
          d)   general shape when heat-relaxed.

     3.   Examine prepared slides of Longidorus and Xiphinema.  Note differences in odontostyle and odontophore.

     4.   Note the taxonomic position of these nematodes in the orders Dorylaimida and Triplonchida.

     5.   Examine descriptive charts of these plant-parasitic nematodes in the Dorylaimida and Triplonchida

     6.   Examine nematode communities of student samples. 

     7.   Videotape:   Xiphinema index feeding on roots of seedlings.

     8.  Complete the field trip sampling study.   Report to the class your conclusions about the reliability of the sampling strategies we used for measuring nematode populations in alfalfa.

     9.  Study photographs of characteristics and damage by migratory ectoparasites: Xiphinema, Longidorus and Trichodorus.  Also, slides of the ultrastructure of these nematodes

    10.   Homework Assignment:

          NEMAPLEX Exercise
          Main Menu:
               Select...Biology and Taxonomy
                Select..Phylogenetic Classification
               Select...Order Dorylaimida
                           Review characteristics of this Order.
               Select...Longidoridae
                           Review Longidorus, Paralongidorus, Xiphinema, including some of the species.

                    Return to Classification Menu
               Select...Order Triplonchida
                           Review characteristics of this Order.

                Select...Trichodoridae
                           Review Trichodorus, Paratrichodorus, including some of the species.
                    
            Return to Main Menu
            
             Select...General Nematology
                Select...Nematodes as Plant Parasites
                   Select...Nematodes as Virus Vectors
            Return to Main Menu
               

     11.   Nemabase Exercise
          Review the host range of these nematodes.  What are the indicated non-hosts?
          In Nemabase select "All Plants" and "Genus" to the genus of interest.
          Set "Host" filter to Host.  Process.

Return to Nematology 100 Menu