NEMATOLOGY 100   -  FINAL EXAM      Name:
   December 16, 1995        2 hours 
   (50% of overall grade)

   1.  (10 points)
      Describe relationships between seed-gall nematodes and bacteria of the 
      genus Clavibacter.  What nematodes are involved and which crops are 
      affected.  What are the economic consequences?

   2.  (10 points)
      What factors will you consider in designing crop rotation strategies
      for managing plant-parasitic nematodes?
      Discuss the use of this approach for the management of nematodes in the 
      genus Pratylenchus and the genus Globodera.

   3.  (10 points)                                                              
      Match the following. (Some letters may be used several times, others
      may not be used at all.  There may be several answers to each question).
      _________1. Animal parasite                a) Caenorhabditis elegans
      _________2. Plant parasite                 b) Trichodorus similis
      _________3. Predator                       c) Ditylenchus destructor
      _________4. Bacterial-feeding              d) Cephalobus persegnis
      _________5. Lemon-shaped cysts             e) Labronema sp
      _________6. Virus transmission             f) Rotylenchulus reniformis
      _________7. A-rated pest (California)      g) Wuchereria bancrofti
      _________8. Migratory endoparasite         h) Heterodera glycines
      _________9. Order Tylenchida               i) Ascaris suum               
      _________10.Nematode/bacterium interaction j) Pseudomonas solanacearum

   4.  (12 points)
      On December 8, 1994 the California Department of Pesticide Regulation
      announced that permits can be issued in 13 counties for the use of 
      Telone II nematicide.                                                    
      a)  What type of nematicide is Telone and how does it move through soil?
      b)  If you were asked to designate three California crops that you 
          considered to have highest priority for use of this nematicide, 
          what would they be, and why?
      c)  What are the target nematode species in the case of each of your 
          designated crops?
      d)  Discuss the pros and cons of using the nematicide in situations
          where it has not been used for several years.

   5.  (12 points)
      What approaches would you take in attempting to increasing the abundance 
      of parasites and predators of nematodes in a soil so that it becomes
      suppressive to plant-parasitic nematodes?  What do you think the
      probabilitity of success is, and what factors may work against you?

   6.  (12 points)
      The following nematodes are detected in a field to be planted to peach
      in a sandy soil in Merced County, California: two plant-parasitic species
      -  Heterodera schachtii and Meloidogyne incognita, a predaceous 
      nematode- Seinura sp., and at least three species of microbial-feeding 
      nematodes in the family Rhabditidae.                                 
      Recommend any nematode control procedures that you think appropriate, 
      environmentally sound, and economically justifiable.  Indicate the 
      nematodes that you are targeting with each procedure.

   7.  (10 points)
      Describe the distribution and life cycle of the dagger nematode,
      Xiphinema index.

   8.  (10 points)
      Describe the life cycle of a plant-parasitic nematode that is vectored 
      by an insect.

   9.  (4 points)
      Sexual dimorphism is the description used when a male and female 
      nematode differ morphologically.  Sexual dimorphism is found in 
      which of the following genera?





  10.  (10 points)
      Describe the stimuli and responses that result in the syncytial
      feeding sites of Heterodera and Globodera spp.