Laboratory Exercise 5
Rev. 10/23/2012

Purpose:  Ectoparasitic nematodes:  morphology, anatomy, feeding habits -- Tylenchidae, Dolichodoridae, Hoplolaimidae.

1.   Powerpoint presentation of characteristics.

2.   Hand-pick live adult males and females of the true ectoparasites from samples provided.
a) Tylenchus spp. (small stomatostyle, butting esophagus, monovarial, pointed tail)
b) Tylenchorhynchus sp. - stunt nematode - (short stomatostyle, butting esophagus, diovarial, tapered to rounded tail)

Examine mounts of preserved specimens of

a) Dolichodorus heterocephalus - awl nematode - (rounded, offset lip region, long, slender stomatostyle, butting esophagus, diovarial, rounded tail)

b) Belonolaimus longicaudatus - sting nematode - long stomatostyle, overlapping esophagus, diovarial, pointed tail)

Draw the nematodes observing the following characteristic features:

          a)   stylet 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.   Note the taxonomic position of these nematodes in the Tylenchoidea.

     4.   Examine charts of other plant-parasitic nematodes in these families.

     5.   Set up Baermann dishes to determine nematode survival after exposure to plant residues (lab #4).

     6.   Videotape:  Feeding of Trichodorus similis on roots of rape seedlings.

     7.   Videotape:  Nematode egg-laying and egg development (Pelodera sp.).
     8.   Observe and key to family nematodes extracted from student samples.

     9.   Study photographs of characteristics and damage by migratory ectoparasites: Tylenchorhynchus, Dolichodorus, Belonolaimus and family Tylenchidae.
    10.   Homework Assignment:
          NEMAPLEX exercise.
           Main Menu:
               Select...Biology and Taxonomy
                Select..Phylogenetic Classification
                 Select...Rhabditida then Tylenchina
                              ..Review information on genera and species discussed today:  

     11.   Nemabase Exercise

         Review the host range of these nematodes.  What are the indicated non-hosts or resistant plants?

          From the Nemaplex main Menu, select Management and Decision Support, then Nemabase 2012.

         Alternatively, you can access the data from the descriptive page for each nematode. 

          Note that a search on say "Tylenchus" will retrieve any record with"tylenchus: as part of the name, so you would need to sort the list and scroll down to that genus.

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