Specimen Handling Procedures:
There are over 1 million described insects and related arthropods. Many entomologists
estimate another several million more exist. Because of this, identification of a
particular species can be quite difficult. However, when insects are collected in and
around the home it is often very important to identify them. Some insects are beneficial
or only occasional invaders of the home. Under these situations no pest control efforts
need to be implemented. Others can be serious pests, and for these some type of control is
desired. Many times, pests are collected from situations where the damage they cause is
obvious, such as grain beetles in cereal or ants invading a kitchen. Other times, pests
are attracted to lights and it is necessary to try to find the damage they have caused.
This is best illustrated by termites who feed behind walls and are easily overlooked until
reproductives fly to lights at certain times of the year.
Insects can be very difficult to identify for several more reasons.
First, there are so many different kinds of insects that it is impossible for
anyone to know them all.
Second, many insects are small and difficult to see. For small pests, it may be
necessary to use microscopes or other means of magnification in order to observe them. Unfortunately, not everyone has access to this
Third, some insects have life stages that look remarkably different from one
another, so it may be possible to easily identify one stage but not another. For instance,
a fly adult is easily recognized by most people, but not many would recognize a fly
maggot. Click on example below.
There is some basic equipment that is used by entomologists for collecting specimens.
Two types of nets are used to catch insects. A sweep or beating net, made of a heavy cloth
bag, is used to beat or sweep foliage for collecting insects that remain on plants, and an
aerial or butterfly net is used to catch flying or jumping insects such as flies, wasps,
bees, butterflies, moths or grasshoppers. Small insects can be collected using a cotton
swab or a camel's hair brush dipped in alcohol. Most home gardeners, however, use a glass
jar or baggy to scoop the specimen into and then seal them quickly. It is a good idea to
record facts about the specimens when collecting. This information may prove important in
determining what species it is. If possible, collect more than one specimen of its kind,
particularly if they are ants or termites or some other pest which can be obtained in high
numbers with relative ease. But don't jam insects into the container or otherwise force
them since damaged specimens are always more difficult to identify. If the specimen is
mutilated, find a better sample to send.
After the insects are collected, flying insects must be quickly killed to prevent them
from damaging themselves by beating their wings against the walls of their container. Most
insects can be killed by placing them in a container with 70% alcohol (common rubbing
alcohol works just fine.) Beetles, true bugs, bees, wasps, and ants can be preserved in
this fashion. Spiders and aquatic insects can be preserved in alcohol too. Most larvae,
especially white grubs and caterpillars, should be first killed in boiling water and then
placed in alcohol to prevent darkening of the tissues. This procedure involves dropping
the living larva into the boiling water and then allowing it to remain until the water
cools. After removing the specimen from the water, pat it with a paper towel to remove
excess water, and finally transfer the larva into alcohol.
Some insects like Asian cockroaches, butterflies, and moths can be identified best from
dry specimens. Kill them by freezing. Carefully place dead butterflies or moths within a
layer of wax paper to protect their delicate wings. Then place them within an envelope.
Galls and damaged plant material can be carefully wrapped in soft tissue. Do not apply
scotch tape directly to a specimen or crush the insect before putting it in an envelope or
There are several ways to identify insects in and around the home:
1. Do it yourself - If the insect is a common pest, you can compare the specimen
with the color pictures or line drawings in a reference document. To confirm your
identification, you could then read about the type of damage the insect causes, find the
damage, and then compare the two.
2. Use your local County Extension office - In some cases, you may need to have
the specimen identified by a specialist. There are various Insect Identification
Laboratories where you can have difficult specimens identified by experts. A form should
be filled out and taken to your County Extension office* that will supply you with
additional materials for submission of samples. The techniques by which insects are
collected, preserved, and submitted ensures that a proper identification will occur in a
3. Use my service - Fill out the "Help
Request Form" and submit to me by printing a copy and mail to "Jim
Hammond, 2370 Fremali Lane, Mt. Vernon, WA 98273" and enclose $10 for processing (if
specimen submitted). If you provide only insect information, I can not be as reliable in
my identification as I can be if you send me an insect specimen. Be sure the insect is
killed before shipment, however, so you don't inadvertently spread pests from one area to
Materials for Submission of Samples
Help Request Form (Insect Identification).
A properly addressed mailing tube, if you must ship it.
A container, if the specimen is to be preserved in alcohol.
A zip lock bag (baggy) or envelope for dry specimens; wrap in wax paper, if moths, etc.
Fill out the appropriate form with the necessary information, but also include as much
information as possible. Write in pencil or with a permanent ink that will resist
smearing; in case the form gets wet. This way there is always legible information. As
added insurance, place the information sheet within a zip lock bag. The bag will protect
the paperwork from damage if the container breaks or if alcohol leaks out. Place your
specimens in the vial and fill with an alcohol solution. The alcohol preserves the insect
so it will not decay. Screw the container cap on tightly, because many times the alcohol
leaks out during shipment and the specimen is destroyed upon arrival. Place the zip lock
bag or container and the insect specimen inside a mailing tube, if it is to be shipped. Be
sure that your name and address appears on any forms and on the insect container. Ship or
deliver samples to the local County Extension office* or me as quickly as possible.
The County Extension office* or I will identify the specimen or notify the sender about
its status within two weeks. The results and the appropriate recommendations will be
written on the Form. A copy of the report will be sent to the name which appears on the
Form. When necessary, the sample will be forwarded to another specialist. Depending upon
the sample and where it will need to be routed, additional time for identification by the
specialist may be required.
* For example, for Skagit County, Washington, the address is (look in your local phone
directory for your area):
Skagit County Cooperative Extension
Washington State University
220 E. College Way
Mt. Vernon, WA 98273
Last edited: 11/12/98 01:00 AM