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
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.
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
Answer by using the appropriate letter.
(i) Order: a) Tylenchida,
(ii) Esophagus type : a) tylenchid - butting,
b) tylenchid - overlapping,
(iii) Number of ovaries (female): a) one,
c)more than two.
(iv) Known vector of a plant virus? a)no,
(v) Adult female feeding habit: a)
(vi) Provide a recognized common name.
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
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