NEMATOLOGY 100 - FINAL EXAM Name:
(50% of overall grade)
December 18, 1993 2 hours
1. (15 points)
Discuss the life cycle, mode of parasitism and survival of
the rice root nematode, Hirschmanniella oryzae. A related
species, H. belli, occurs in California; what factors govern
its importance in rice production?
2. (15 points)
Briefly describe the modes of parasitism of the fungi that are
antagonistic to nematodes. Provide examples where possible.
3. (15 points)
What strategies are available for management of nematodes in
perennial crops? Consider options before planting and for
established orchards.
4. (10 points)
List factors to be considered when selecting cover crops for
nematode management.
5. (10 points)
A tomato variety resistant to the soil fungus Fusarium
oxysporum succumbs to fusarium wilt when planted in certain
fields. The incidence of the disease is negligible when the
fields are treated with a broad spectrum soil fumigant. In
other fields the variety performs well and retains its
resistance. Outline the treatments you will use to determine
the cause of resistance failure. Explain your treatment
selection.
6. (10 points)
Belonolaimus longicaudatus, the sting nematode, is an
important parasites of cotton and soybeans in the southeastern
U.S. How are plants damaged? Assess the potential for this
nematode becoming a significant problem in California
agriculture.
7. (15 points)
Briefly discuss the economic importance, distribution and host
range of the burrowing nematode, Radopholus similis. Outline
a control program for a crop on which it is a major pest.
8. (10 points)
Associate code letters for the organisms on the right with the
descriptors on the left. (Some letters may be used several
times, others may not be used at all. Examples for each
descriptor may range from none to several, provide all that
apply.)
_________1. Animal parasite a) Caenorhabditis elegans
b) Mesocriconema xenoplax
_________2. Fungus feeder c) Xiphinema californicum
d) Ditylenchus destructor
_________3. Predator e) Acrobeloides bodenheimeri
f) Mononchus papillatus
_________4. Bacterial feeder g) Heterodera glycines
h) Globodera rostochiensis
_________5. Host-mediated egg i) Trichinella spiralis
hatch j) Pseudomonas solanacearum
_________6. Virus transmission k) Rotylenchulus reniformis
l) Seinura demani
_________7. A-rated pest (CDFA) m) Ascaris suum
_________8. Sub-order Aphelenchina
_________9. Nematode/bacterium interaction
_________10. Seed galls