simply because there is less reading to do. There is more visual matching. The couplet
key, on the other hand, provides descriptive statements that must be carefully read.
Inexperienced personnel often find the pictorial key easier to work with, but both
pictorial and couplet keys can be used alternately in the field, in the laboratory, or in the
classroom.
d. The only way to become truly famiIiar and comfortable with standard
identification keys is by using them. In this lesson, you have already seen examples of
pictorial and couplet keys that wiII identify an unknown specimen to class and order.
Additional pictorial keys are shown in Appendix A. Since much of the preventive
medicine technician's work in entomology involves mosquitoes, these keys are Iimited
to mosquito identification. The keys in Appendix A wiII enable the reader to identify
larval or adult mosquitoes to genus level.
1.
Three or 4 pairs of walking legs (1 A & B)...........................................................2
Five more pairs of walking legs (1 C & D).........................................................33
2.
Three pairs of legs walking (2 A)................................................................3
Four pairs of walking legs (2 B)...............................................................25
3. Wings present, well developed (3 A)..................................................................4
Wings absent or rudimentary (3 B & C)...............................................................13
Figure 2-2. Standard identification key (continued)
MD0170
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