MIDTRM98.HLP Rev 11/98 Nematology 100 MID-TERM EXAM 11/04/98 90 minutes 1. (25 points) You are provided with nematodes that represent a composite of samples from landcscape vegertation around campus. a. Place an adult female plant-parasitic nematode of any species on a microscope slide. Kill the nematode 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 Köhler illumination. 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. Grading: adult female plant-parasite, good condition - 15 pts non-parasite, good condition - 8 pts correct designation of Class and Order - 2 pts correct drawing and identification of stylet/esophagus - 8 pts points off for damage, distortion, dry slides, etc. 2. (15 points) Describe, with the aid of drawings, the components and various configurations of the female reproductive system nematodes. Briefly describe the function of each structure. 3. (10 points) Describe the geographic location and soil conditions that favor the sting nematode, Belonolaimus longicaudatus. What crops are damaged? (10 points) 4. Describe the life cycle of Paratylenchus hamatus (the pin nematode), indicate survival/persistent stages and discuss the nature and importance of males. 5. a) Sketch the anterior portion of 3 nematode genera which are vectors of viruses. b) Identify each genus drawn. c) List the particle type and virus classification for each genus. d) Discuss the location of the virus in the nematode and persistence or transmission of the virus across various stages of the nematode life cycle. e) (i) Name a nematode vectored virus disease in California. (ii) Name the vector. (iii) Name the plant host. (iv) What group is the virus classified in? (10 points) 6. Describe the feeding process in Paratrichodorus minor (the stubby root nematode). 7. (20 points) Provide the following information for each of the nematodes listed. Answer by using the appropriate letter. (i) Order: a) Tylenchida, b) Rhabditida, c) Diplogasterida, d) Dorylaimida. (ii) esophagus type : a) tylenchid - butting, b) tylenchid - overlapping, c) dorylaimid. (iii) Number of ovaries (female): a) one, b) two, c)more than two. (iv) Known vector of a plant virus? a)no, b)yes. (v) Adult female feeding habit: a) migratory ectoparasite, b) migratory endoparasite, c) sedentary endoparasite. (vi) Provide a recognized common name. Paratylenchus neoamblycephalus 8. (10 points) Which genera of nematodes transmit NEPO viruses? Where are the particles carried in each genus? 9. (10 points) Briefly describe the excretory systems of a tylenchid and a dorylaimid nematode.