Entomology 311 Lab Manual - 1st Edition, 2019

If insects are caught alive, it is best to have an ethyl acetatecharged
kill jar available, as well as escape-proof vials, cups, or
other storage containers (figure 1-9). Often, removing insects from
a sweep net or live trap into a kill jar is the most difficult part of
preserving specimens. The end of most nets are mesh and can be
placed directly into a kill jar (provided the kill jar is large enough),
and the lid screwed lightly down as far as possible should keep
enough ethyl acetate around the specimen to cause temporary
knock-down. At this point (usually 1-2 minutes), the specimen can
be quickly removed from the net and placed into the kill jar, firmly
closing the jar.
Once collection is complete, all specimens should be frozen
within 12 hours to prevent fungal growth that will ruin the
specimen, and to make sure the specimen is dead. Some beetle and
spiders require a full 24 hours frozen to ensure death. Large, wetbodied
insects, i.e. Praying Mantis, should be frozen outside of a
container to begin the drying process.
Specimens may remain in a freezer as long as needed, and
following a freezing period most arthropods can be immediately
pinned or placed into ethanol. Non-insect arthropods are always
preserved in vials of ethanol, as well as soft-bodied, larval, or very
Figure 1-9: An ethyl acetate-charged kill jar for
dispatching insects that are caught alive.
small insects like aphids and midges. If the body of the arthropod is soft and fluid filled, it most likely will require
preservation in ethanol. If the insect body has hardened cuticle, it will be preserved on a pin. General Rule: If you
were to step on it, would it squish (ethanol) or crunch (pin)? Some larger insects (Large grasshoppers, mantids,
large bot flies and horse flies) have enough oil and body water that they should be allowed to dry out for a few days
before pinning. To prevent fungal growth, alternate 12-hr periods in and out of the freezer until sufficiently dry.
Materials: Preservative Ethanol should be diluted to a 70% for specimen preservation. If ethyl acetate is not
available for kill jar charging, acetone-based fingernail polish remover is an inexpensive alternative, though it does
not work as fast and will require more frequent re-charging. Kill jars can be purchased, but they can also be easily
made with a jar and plaster of Paris. Once mixed, layer an inch of plaster into the bottom of the jar and allow to dry
– having several kill jars available for use makes prolonged collecting easier.
Part III. Curation
Pinning: In general, the pin is inserted into the second section of the thorax, though there are few exceptions.
Insertion will be into the right side of the insect (from above) to make sure that at least one complete half of the
thorax will be undamaged, preventing loss of structures used in identification. Pin position is indicated on the
diagram below for the different insect body types (figure 1-10).
Week 1: Reading | 15