Laboratory Exercise 6
Purpose: Ectoparasitic nematodes of the Criconematoidea.
anatomy, feeding habits:
Criconematidae: Criconematinae and Hemicycliophorinae;
1. Powerpoint presentation and slides of characteristics.
2. Hand-pick, from the specimens provided, live adult males and females of:
Draw the nematodes, observing the following characteristic features:
length and morphology.
b) esophagus type and anatomy, nature of postcorpus, interface with intestine.
c) male and female reproductive structures.
d) general shape when heat-relaxed.
There are questions regarding identification of the nematodes indicated as Criconemoides. The genus (sensu lato) has undergone several redescriptions over the last 20 years. Use the key to the Criconematidae provided in Nemaplex.
4. Note the taxonomic position of these nematodes in the Criconematoidea.
5. Examine descriptive charts of these and other plant-parasitic nematodes in the Criconematoidea.
6. Determine numbers of surviving nematodes
from the plant residues experiment set up in lab #4. Calculate
mortality rates in the amended (A) relative to the unamended (U) control treatments.
The calculation is
100(U-A)/U. Please be prepared to report your result and conclusion in class on
Friday. What are the flaws in the experimental design? Would you design the
7. Complete field trip sampling exercise:
a) Reliability of population estimates.
8. Movie: the sheath nematode, Hemicycliophora arenaria.
9. Study photographs of characteristics and damage by migratory ectoparasites: Criconemoides, Hemicycliophora and Paratylenchus.
10. Homework Assignment:
Review the host range of
these nematodes. What are the indicated non-hosts? Are there
resistant cultivars available?
From the Nemaplex main Menu, select Management and Decision Support, then Nemabase 2012.
Alternatively, you can access the data from the descriptive page for each nematode.
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