NEMATOLOGY 100 MID-TERM EXAM -- 1 1/2 HOURS NOVEMBER 2, 1988

  1.  (20 points) 

You are provided with nematodes extracted from a lawn at Orchard Park Student Housing.

• Place an adult female plant-parasitic nematode of any species in the order Tylenchida on a microscope slide. 
• Heat-kill the nematode with gentle heat before applying a coverslip.
• Place the slide on the compound microscope. 
• Call the instructor for examination of your nematode.  If there is more than one nematode present in the microscope field, indicate the specimen you wish to have examined.  Do not ask or expect the instructor to make the selection.
         Only the nematode that you indicate initially will be considered.  You should not have to leave your bench position.

       Grading:
         adult female plant-parasite (Tylenchida), good condition - 10 pts
         non-parasite, good condition -                              2 pts
         points off for damage, distortion, dry slides, etc.

   2.  (15 points) The nematode drawing is extracted from a paper by N.A. Cobb
  	 in the 1914 edition of the USDA Yearbook of Agriculture.
   a.  What order of the Nematoda is this nematode in?
   b.  Label the parts of the stylet.
   c.  Label the parts of the esophagus.
   d.  Label the parts of the reproductive structures.
   e.  Provide a technical description of the reproductive structures.

   3.  (15 points) Describe the life cycle and feeding habits of nematodes in 
       the genus Radopholus.  Briefly describe the damage caused by a species 
       of this genus to citrus.

   4.  (10 points) Describe the proposed causality of bacterial canker of 
       peach in California.

   5.  (10 points) Describe the geographic location and soil conditions that 
       favor the sting nematode, Belonolaimus longicaudatus.  What crops are 
       damaged?

   6.  (10 points) Name 2 nematode genera in diffent orders in which 
       hyperplasia is induced in root tissues.  How is the hyperplasia
       expressed in the host plants of these nematodes.

   7.  (20 points) Provide the following information for each of the nematodes 
       listed.
       Answer by using the appropriate letter.

       (i) Order: a)Tylenchida, b)Rhabditida, c)Diplogastrida, d) Dorylaimida
      (ii) Esophagus type : a)tylenchid - butting, b)tylenchid - overlapping,
             c)dorylaimid.
     (iii) Number of ovaries (female): a) one, b) two, c)more than two.
      (iv) Known vector of a plant virus? a)no, b)yes.
       (v) Adult female feeding habit: a) migratory ectoparasite,    
            b) migratory endoparasite, c) sedentary endoparasite.
      (vi) Provide a recognized common name.

           Dolichodorus heterocephalus
         

          (i)
         (ii)
        (iii)
         (iv)
          (v)
         (vi)

           Helicotylenchus dihystera
         

          (i)
         (ii)
        (iii)
         (iv)
          (v)
         (vi)

          Pratylenchus penetrans
         

          (i)
         (ii)
        (iii)
         (iv)
          (v)
         (vi)

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