NEMATOLOGY 100 MID-TERM EXAM -- 1 1/2 HOURS OCTOBER 30, 1991

    1.  (20 points) Like generations of Nematology 100 students before you,
       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 - 20 pts
         plant-parasite not in Tylenchida                            8 pts
         non-parasite, good condition -                              4 pts
         points off for damage, distortion, dry slides, etc.

   2.  (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.
           Paratylenchus neoamblycephalus
         
          (i)
         (ii)
        (iii)
         (iv)
          (v)
         (vi)
           Tylenchorhynchus claytoni  
         
          (i)
         (ii)
        (iii)
         (iv)
          (v)
         (vi)
           Paratrichodorus minor      
         
          (i)
         (ii)
        (iii)
         (iv)
          (v)
         (vi)


  3.  (15 points) Provide a generalized drawing of an adult male nematode with a
      tylenchid esophagus, and with the dorsal esophageal gland longer and
      larger than the subventral esophageal glands.  Label the features of: 
       a) the stoma regions,
       b) the esophagus,
       c) the digestive tract,
       d) the reproductive system, including copulatory structures.

  4.  (10 points) Longidorus africanus is an important parasite of carrots in
      the southern desert valleys of California.  Describe the symptoms of
      damage to carrots by L. africanus.
      What recommendations would you make for managing this problem?

  5.  (10 points) Which genera of nematodes transmit NEPO viruses?  Where are
      the particles carried in each genus?

  6.  (15 points) Describe the impact of irrigation practices on the population
      biology of the sheath nematode, Hemicycliophora arenaria.

  7.  (10 points) Briefly describe the excretory systems of a tylenchid and a
      dorylaimid nematode.
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