Damselfly Size
Damselflies in North America don't vary in size as much as dragonflies,
varying from about 1 inch to a little over 2 inches in length. Correctly estimating
the size is important in identification but can be tricky. Some books express
length in inches, others in millimeters, and some use both. Length refers
to the measurement from the "nose" to the "tail tip."
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Actual size on a monitor can vary but the size
difference between the American Rubyspot and the Sedge Sprite is accurately
represented in this composite.
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How do you know the exact size of the Damsel you are looking at?
If you are holding it, it's pretty easy to measure it, but when you are watching
a free-flying Ode, it can be pretty hard to figure out.
Comparison to other odes may be the easiest. Once you know
1 or 2 species, compare your unknown bug to others nearby. When you have been
watching Familiar Bluets, a Skimming Bluet will look tiny.
Many field guides and manuals include the size. But converting
from millimeters to inches and back can make you crazy. Some guides go a bit further
and include a ruler printed along the cover. A few even use bars or lines
to indicate the actual length of the insect. These are great if you are holding
the insect but can also help give a visual impression of the length.
Remember that the lengths printed are estimates of the average damselfly
or ranges of size. In general, females are larger than males although there
are exceptions. Also species may have very large and very small individuals.
For very precise measurements in-hand, you may need to purchase
calipers. These can be necessary for serious students who need to measure
the exact width of an abdomen or length of claspers. See our
equipment section for some help with this.
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