NEMATOLOGY 100 MID-TERM EXAM -- 1 1/2 HOURS
20041. (25 points)
You are provided with nematodes extracted from a walnut orchard interplanted with alfalfa
a. Place an adult female plant-feeding nematode of the Order Tylenchida on a microscope slide.
b. Indicate on your exam sheet the Class and Order of your nematode.
c. Draw and label the component parts of the stylet and esophagus for this type of nematode (either from your specimen, or from your knowledge of anatomy and morphology, or both).
d. 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.
2. (15 points)
The composite nematode drawing is extracted from a paper by Gerald Thorne in the 1943 volume of the Proceedings of the Helminthological Society of Washington. We did not study this genus in class but it is a parasite of walnut.
Here is a key to the component parts of the drawings:
(i) What is the probable feeding habit of this nematode? (give reasons).
(ii) In which order of the Nematoda would you place this genus, and why?
(iii) Use the appropriate letter to label structures on the drawings. Only label each structure one time - on the drawing in which it is most obvious.
3. (10 points)
4. (15 points)
Briefly describe the technique that you would use (and why you would use it) to detect the presence of the following nematodes in a sample:
e. Stubby root nematode (Paratrichodorus minor) in soil from a cotton field.
5. (10 points)
Describe the life history, feeding habits and mode of parasitism of the rice root nematode (Hirschmanniella oryzae). What is the longevity of this nematode under adverse conditions and how would you create such conditions?
6. (10 points)
7. (15 points)
Spiral nematodes (Helicotylenchus multicinctus) and burrowing nematode (Radopholus similis) are important parasites of bananas in central America.