Nematology 100 Name:
MID-TERM EXAM, 10/30/02
1. (25 points)
[Note: the sample contained large numbers of Hirschmanniella spp.]
2. (10 points)
On the field trip you recovered the
dagger nematode from a grape vineyard and the
lesion nematode from a
walnut orchard. You also studied the nematodes in the laboratory.
Provide the following general and diagnostic characters in the table below (answer by using the appropriate letter).
|(i) Order:||(ii) Esophagus type||(iii) Ovaries?|
|(iv) Virus vector?
|(v) Adult female feeding habit?||(vi) Provide an important economic host (other than the one from
where you recovered the nematode).
|Genus and species|
|Common name||Lesion Nematode||Dagger Nematode|
3. (10 points)
Describe the geographic locations and cropping systems in which you might expect damage by the spiral nematode, Helicotylenchus multicinctus. Describe the nature of the damage.
4. (15 points)
Describe the soil conditions that favor the awl nematode, Dolichodorus heterocephalus and the sting nematode, Belonolaimus longicaudatus. What crops are damaged by each nematode?
5. (15 points)
a) What is the size and shape of Nepoviruses particles?
b) Provide genera or common names of two nematodes that transmit Nepoviruses.
c) Describe the symptoms and crop damage caused by grapevine fanleaf virus. What are the effects of the virus on the vector?
d) Are plant viruses passed through the nematode egg stage to subsequent generations?
6. (15 points)
Briefly describe the technique that you would use to detect the presence of the following nematodes:
a. Paratylenchus hamatus (a pin nematode) from soil around walnut roots
b. Pratylenchus vulnus (a lesion nematode) in bare-root nursery stock
c. Belonolaimus longicaudatus (sting nematode) in fallow soil
7. (10 points)
List six diagnostic characteristics of the Phylum Nematoda. Provide three diagnostic differences between nematodes and annelids.