NEMATOLOGY 100   -  FINAL EXAM             Name:


(50% of overall grade)  December 12, 2002        2 hours

1.  (15 points)
a) Discuss the life cycle, mode of parasitism and survival of the pinewood nematode, Bursaphelenchus xylophilus. 

b) What factors contribute to its importance in pine forests?
 

2.  (10 points)

How, and in what forms, can heat be used to kill nematodes?  Explain an application to illustrate each case.   Indicate the constraints associated with each application.

3.  (10 points)
 How have natural plant compounds such as root exudates, plant constituents, or other plant-derived materials been used or tested in nematode management?  What are the modes of action?

4. (10 points)
Sexual dimorphism is found in which of the following genera?

For each genus in which there is sexual dimorphism, indicate the general shape of females and males.

        Pratylenchus

        Tylenchulus

        Tylenchorhynchus

        Globodera

        Rotylenchulus

5.  (15 points)
A retired UC Davis professor purchased an established walnut orchard near Winters, California, so that she could remain active and supplement her retirement income.  Unfortunately, the orchard is not very productive and trees are declining in vigor.  The high numbers of Pratylenchus vulnus in the roots and soil indicate that this nematode is probably the cause of the problem.  What advice will you provide to the former professor so that she can realize her retirement plan?  Please don't tell her to pull out the orchard and start again, the delay would be too long!

6.  (15 points)
a) What approaches would you take in attempting to make a soil suppressive to plant-parasitic nematodes? 

b) What do you think the probability of success is, and what factors may work against you? 

c) List some of the mechanisms of suppression that you would hope to achieve.

d) How would you go about testing the suppressiveness of the soil?


 7.  (10 points)
Nematode breadth question.  Provide potential matches for the following "factoids". (Some letters may be used several times, others may not be used at all.  There may be several matches to each factoid).

8.  (15 points)
Ditylenchus destructor is an important pest of peanut production in South Africa. 
a) Discuss the biological and economic components of the problem.
b) What approaches would you include in a research program to develop management strategies for this pest on peanut.

9.  Feedback Question (no points!)

NEMAPLEX- how useful is it?  Your suggestions for improvements and inclusions.