MID-TERM EXAM, 10/31/01
1. (25 points)
- You are provided with nematodes extracted from submerged roots and
rhizomes of common cattail (Typha latifolia) and other reedy plants in an irrigation ditch near
- a. Place an adult female and an adult male plant-parasitic nematode of
any species on a microscope slide. You may place both nematodes on
the same slide or on separate slides.
- Kill the nematodes with gentle heat.
- Apply a coverslip.
- Seal the edge of the coverslip with fingernail polish
to prevent the slide from drying out.
- Place the slide on the compound microscope and adjust
the microscope to provide
- b. Indicate on your exam sheet the Class and Order of
- c. Draw and label the component parts of the
and esophagus for this type of nematode (either from your
specimens, or from your knowledge of anatomy and morphology, or both).
d. Which of the morphological and anatomical characteristics of the
specimens suggest that the nematodes
feed as ectoparasites
e. Call the instructor for examination of your
male and female nematodes. If there is more than one nematode present in
the microscope field, indicate the specimen you wish to
have examined. Do not expect the instructor to
make the selection.
Only the nematodes that you indicate initially will be
- adult female plant-parasite, good condition 6 pts
- adult male plant-parasite, good condition
- correct designation of Class and Order 2 pts
- reasonable justification of feeding habit designation
- correct drawing and identification of stylet/esophagus 8 pts
- points off for damage, distortion, dry slides, etc.
2. (10 points)
(i) What are the
functions of plant roots?
(ii) List the ways in which plant roots may be damaged by, or respond to, plant-parasitic nematodes.
3. (15 points)
In the table below, provide the following information
for each of the nematodes listed (answer by using the
(ii) Esophagus type
(iv) Virus vector?
(v) Adult female feeding habit?
(vi) Provide an important economic host.
4. (10 points)
Describe the geographic location and soil conditions that favor the sting nematode, Belonolaimus longicaudatus. What crops are damaged?
5. (15 points)
a) Describe the processes of
acquisition, retention (retention sites, mechanism and retention period), and
transmission of plant viruses by plant-parasitic nematodes.
b) Which genera of nematodes
transmit Nepo viruses?
c) Indicate two virus
diseases, and the crops affected, that are vectored by species of
Briefly describe an
separating ring and other slow-moving nematodes from soil.
7. (15 points)
Radopholus similis is an important parasite of bananas in
Cameroun, West Africa.
- Describe the damage that this nematode causes to the plant root system.
- Describe how this damage translates into crop loss.
- What methods are used to eliminate the nematode from planting stock?
- What methods are used to minimize the nematode damage in established plantations?