Using Dead Insects To I.D. Live Ones

Collecting, preserving and displaying insects is an excellent way to help technicians learn the nuances involved in correctly identifying pests.

Roger is a newly trained service professional who has been working a route on his own for about two months. He is a hard worker, but his manager notices he has been experiencing too many service callbacks. His manager decides to spend a day with Roger, and finds that the technician has trouble identifying common pests that are being encountered during routine preventive services. Roger, therefore, has been applying treatments in the wrong areas because he is not inspecting the sites where the target pest is most likely to be found. Obviously, Roger requires additional training in pest identification. What is the best way to accomplish this training?

Too often, pest control companies do not provide enough good training in identifying insects and other arthropods. This type of training often involves books and videos, but these materials are no substitute for observing and studying the actual insect, spider, or tick itself. Building a training collection for each office in a company is the best way to ensure that new service and sales professionals get a good start in their careers. Such collections are also good for periodic testing of all company individuals to keep their skills sharp. All effective pest management programs begin with correct identification of the pest(s) involved, so it makes sense to put effort into creating and maintaining a training collection.

GETTING STARTED. Before the first insect is collected, a small amount of planning and some supplies are required. First, prepare a list of pests that should be included in the training collection, and divide the list into two columns. The first column will include the 12 to 15 most commonly encountered pests for your area, and the second list will contain the less commonly encountered pests that your employees need to be able to identify. Both lists will probably be longer in southern states, where more different species of insects are likely to be found. Focus initial efforts on collecting the most commonly encountered pests in the first column.

After the list is made, a few supplies will be needed for collecting the specimens to be used in the collection. The most important item required is a set of collection vials. It is a good idea to have several different sizes of vials. Do not skimp on having vials available keep 150 to 200 on hand. The cost of the vials will be $70 to $100. They can be obtained from BioQuip Products of Gardena, Calif., 310/324-0620. Be sure to buy vials that have a plastic seal; otherwise the alcohol used to preserve specimens may dry out over a long period of time.

Other supplies that will be needed for collecting, preserving and displaying insects include a killing jar, ethyl acetate, 70% isopropyl rubbing alcohol, foam spreading boards, insect pins (sizes #000, #1, and #2), both soft and hard insect forceps, an aspirator (optional), riker mounts (2½ ´ 3 inches and 4 ´ 5 inches), and display boxes (wood boxes are best but cardboard boxes with glass tops are available). These items are all available from BioQuip Products. Their use will be discussed later in this article. BioQuip also sells a short guide on the procedures for collecting and preserving insects.

COLLECTING SPECIMENS. The quickest way to obtain a variety of specimens quickly is to charge sales and service professionals with the task. Instruct employees to collect any specimens they find and to gather as many specimens as possible. The purpose for collecting many specimens of each type of pest is that specimens are often broken during training, so a backup supply isneeded. It is also important to have both a study collection and testing collections.

Specimens may be returned to the office in a variety of containers, such as zip-lock bags, pill bottles, and jars, which customers often provide to sales and service professionals. It is important to immediately transfer specimens into a suitable container and preserving fluid (e.g. alcohol) or to spread them to dry on foam boards using pins. Specimens that are left in jars or zip-lock bags without preserving fluid tend to rot after a few days.

Certain insects such as ants and stored product pests are easy to collect in large numbers. For ants, scoop or brush a large number of live ants into a zip-lock bag and bring it back to the office to transfer the individual ants into a vial of alcohol. Pour small amounts of the material (soil, grass, etc.) containing the ants into a pie pan and remove the individual ants using soft forceps or an aspirator. Transfer the ants into a vial containing 70% isopropyl alcohol and label the vial. Ants can also be collected in the field from their trails on walls, floors, and other hard surfaces by using an aspirator.

Whenever stored product pests are encountered, bring a sample of the infested material back to the office. If large numbers of specimens are present in the sample, transfer them using forceps or an aspirator into a vial containing alcohol. Indian meal moths and similar moths should not be stored in alcohol; instead, they should be killed by freezing, then dried and stored in a dry, empty vial. If the infested food item does not have enough stored product beetles or moths, the material can be transferred into a jar, and specimens can be raised for future collection and preservation.

Cockroaches can be difficult to collect in large numbers. Trapping these insects is one method for collecting large numbers of cockroaches. Another method is rearing them in 5-gallon plastic buckets. Cockroach trapping is accomplished by placing strips of masking tape on the outside of Mason jars from the top to the bottom. Smear a thin layer of petroleum jelly around the inside lip of the jar and place a piece of bread soaked in beer inside the jar. Place numerous such traps in areas known to be infested by the target cockroach, then check the traps the next day. Captured cockroaches should be killed by freezing or in a killing jar using ethyl acetate, or transferred to 5-gallon buckets with lids for rearing purposes.

If you decide to rear cockroaches, install a screen in the bucket's lid, smear a layer of petroleum jelly around the inside top of the bucket, and place sand, cardboard tube shelters, water, and dried pet food in the bucket with the cockroaches. An aquarium can also be used if it has a screened lid. Once a week, feed the cockroaches some banana or apple, but remove the uneaten portions of the fruit after a couple of days to prevent molding or the development of fruit flies.

Instruct employees that when they find large numbers of a particular pest, they should collect as many specimens as possible (without expending too much time to do so). For example, cluster flies or boxelder bugs may be encountered inside a building in large numbers, and these insects can be swept into a zip-lock bag or jar. A single "find" of a pest may provide enough specimens so that future collecting of that pest is no longer necessary.

PRESERVING INSECTS. Soft-bodied insects such as insect larvae and termites must be stored in preserving fluid such as 70% isopropyl alcohol. Before storing moth or beetle larvae in alcohol, however, the larvae should be killed by boiling in water; otherwise the internal fluids of the larvae break down, causing the larvae to turn brown or black. Spiders should also be stored in alcohol in vials.

Ants, fleas, ticks, springtails, amphipods, and similar small arthropods can be preserved directly in alcohol. Larger insects such as cockroaches, crickets, bees, and wasps can be killed directly in alcohol in vials or small jars, or in a killing jar with ethyl acetate; these insects may break down in the alcohol after several years of storage, however. These larger insects should be pinned on foam spreading boards, allowed to dry, then stored in display boxes for future use. Spread the legs and antennae using pins so that all identifying characteristics can be seen. The wings of bees, wasps, butterflies, etc., need to be held in place using small strips of paper pinned to the spreading board.

DISPLAYING INSECTS. For a study collection, larger insects can be mounted on pins iin a glass-topped display case or can be displayed in individual riker mounts. Place an identifying label next to or under each insect. Soft-bodied insects such as termites and springtails and other small insects such as fleas, ants, and ticks need to be removed from their vials and placed on a microscope slide or in a small petri dish for examination under a magnifying device. The specimen should be placed back into the vial after the examination.

For testing collections, place individual specimens in riker mounts or vials and number them. Keep a master list of the numbered specimens and their identities. If using a group teaching approach, number the specimens 1-1, 2-1, etc., for group #1 specimen #1, group #2 specimen #1, etc. Examine the study and testing collections on a regular basis and replace damaged specimens. It is important that trainees examine good specimens; this will make indentification easier in the field.

Preparing a useful insect collection is not difficult, but it does take a little effort in planning, collecting, and displaying the specimens. Restrict the collection to the most common pests to begin with, and add any interesting specimens that employees may bring in. Use the collection several times per year to retrain all employees, because correct identification is the key to successful solutions to any structural pest infestation. Trainees learn identification best from examining actual specimens, so take the time to prepare training collections for each office in your company.