Volume 13, Number 1, Jan. 1991, pp.19-20

Insect Monitoring in Museums

Integrated Pest Management

In recent years, many museums have developed and implemented Integrated Pest Management (IPM) programs--holistic programs for the control of pests such as insects, rodents and birds. IPM is the pest-control industry term for a systematic, stepwise approach to pest problems. The IPM approach includes: (1) initial assessment of insect or other pest problems in the museum, (2) infestation prevention by inspection of materials brought into the museum and careful control of other possible insect entry points, (3) development of a procedure for eradication of pests that are present in the museum, and (4) evaluation of the insect-control procedure or plan.

Sticky Traps

Monitoring the presence of pests through the use of traps is the first step in IPM programs. Insect monitoring traps, commonly referred to as "sticky traps," are used to pinpoint infestation hot spots, identify sites where insects enter an area and discover which insects are present and in what quantities. Insect sticky traps were developed in the mid-1970s in the United States. Their use in museums began in the early 1980s when conservators began to question the widespread use of pesticide chemicals with artifacts in the absence of concrete knowledge about what insects actually were present. Monitoring can help museum professionals to learn which insects are present, the extent of an infestation, as well as insect population and distribution patterns within a museum.

Sticky traps are produced by many manufacturers and come in several configurations. The flat "glue board," the box-shaped "motel," and the triangular-shaped "pup tent" are common forms. I personally prefer the pup tent traps. I have found them to be easier than flat traps to handle and transport once insects have been caught, also, they are easier to open up for insect identification than the rectangular shaped "motels." Sticky traps may have a plain adhesive layer on the inner surface, or they may have a food bait mixed with the adhesive to act as an attractor. Insect attracting hormones (pheromones), also have been used in sticky traps, but pheromone baits are not available for every type of museum insect pest. In my experience, the attractant traps are not significantly more useful than traps that are just sticky.

Steps for an Insect Monitoring Program

Setting up an insect monitoring program using traps should include the following steps.

1. Obtain a floor plan of the museum. Be sure to identify all doors, windows, drains, air vents and returns, food sources and plants.
2. Mark on the floor plan the places where traps should be put. Initially, traps should be placed at various heights, including on the floor, on shelves, and in false ceilings. Other critical locations include: near doors and loading docks, in shop areas and collection work areas, around perimeter walls, under furniture, inside exhibit and storage cabinets, and near heat and water sources. In areas where infestation is suspected, traps should be placed every 10 feet. Traps should not be placed on, or directly adjacent to, museum artifacts--the sticky adhesive may be damaging and difficult to remove. With good placement, it will be possible to determine where the pests are entering and why they are surviving.
3. Chose the traps to use for monitoring. Conservators that have been using sticky traps will probably have preferences as to the types they like best. The size of the area to be monitored, the budget and the types of insects expected will factor in choosing the trap style. However, many conservators find the "pup tent" style that hooks at the top to be the easiest to set, handle and examine. It is often suggested that a monitoring program should stay with the same brand of trap because many variations can make your data more difficult to interpret.
4. Place traps throughout the facility as indicated on the floor plan. Before placement, each trap should be labeled with a placement date and a location number keyed with the floor plan. If room numbers are already assigned to the building, it may be most useful to utilize that system in labeling the traps. For example, "5/l" might be used to indicate room 5, location 1. If several buildings are being monitored, a building number or abbreviation could precede the room and location numbers.
5. Establish a regular schedule for inspecting and collecting the traps. All traps should be in place for the same length of time so that comparisons between trap catches can be made. An initial check should be made 48 hours after the traps are set. The check is a simple visual inspection of the types and numbers of insects present in the trap--sort of a head count. The same trap can be replaced and a final count may be taken during the scheduled pick-up and trap change. The traps should be checked every week for the first three months. After that, four to six times a year probably will be adequate. Record in a logbook the quantity, life stage, and type of insect found in each trap. Also note the trap number, trap location, date inspected and date the trap was set. Without documentation, the monitoring program is of little use. By checking traps 48 hours after the initial placement, it will be possible to locate the heart of the infestation because the trap nearest this spot should contain the most insects. Routine inspection of the traps will provide important information about the insect types present. A trap with many insects caught on one side and few on the other will indicate the direction of the infestation. The distribution, population, and type of insects found in traps will indicate whether a severe problem exists or merely that a harmless insect was lost in the museum. The stage of development of the trapped insects also can tell something about the duration of the infestation. A mixture of adult males and females and various sized nymphs means that the infestation has been around for months, while a collection of mostly medium sized nymphs means that the infestation is fairly new. A comparison of traps before IPM and after IPM will provide information about the success of such a program.
6. Over time, an insect monitoring program will require refinements based on the information gained about types of insects present, seasonal changes, building structure and housekeeping methods. Traps should be replaced every two or three months because they tend to lose their stickiness. Also, the dead insects within become bait for other insects and allow new insects to enter without crossing over the sticky surface. Trapping will result in insect reduction for some insect species but should not be considered the primary control measure for an infestation.
7. Sticky traps do not replace the need for regular housekeeping and inspection of objects in storage or exhibit. These activities should be done monthly or at least two times per year.

Insect Identification

Identification is critical to an IPM program. All insects caught must be identified to determine whether the collections are at risk. Also, pesticide and fumigation treatments must be designed with knowledge of the pest(s) responsible. To make identifications, entomologists prefer that the insect be completely intact. They suggest placing a larvae or adult in a sealed vial filled with ethanol or rubbing alcohol to prevent it from drying out or breaking apart, and indicating whether the insect was found alive or dead.

In many areas, the county agricultural agent or Extension Service can provide assistance with identification. The Getty Conservation Instistitute also provides an identification service to museums free of charge. Contact: Jim Druzik, Conservation Scientist, GCI, 4503 Glencoe Ave., Marina del Rey, CA 90292-6537; (213) 822-2299.

There are also several books that offer illustrations and information about insect species. See the references listed on page 23 of this issue following "Insect Traps In Conservation on Surveys" by Dale Paul Kronkright.

Supply Sources

Sticky Traps usually can be purchased at hardware stores or pest control suppliers, or they may be ordered from national suppliers. Mail order sources include:

The Trapper (can be used flat or pup-tent shape); available from Pest Control Supplies, P. O. Box 025665, Kansas City, MO 64102; cost: S29.95 per 100 units.

Mr. Sticky (pup-tent shape) available from LTP, Inc., 7 Beach Street, Mt. Vernon, NY 10550; (914) 699-5000 at S25.60 per 40 units and Zone Monitor (pup-tent shape) at S19.20 per 40 units.

Catchmaster (pup-tent style unit with a scent attractor and perforations that allow it to separate into 3 parts) available from Brody Enterprises, 9 Arlington Place, Fair Lawn, NJ 07401; (800)458-8727 at S33.00 per 72 units.

Recon Professional Monitor (box-style motel) available from Protos Corporation, P. O. Box 2236, Cambridge, MA 02238. (price not listed).

WAAC thanks Michael Barton, Editor of Museum Association of Arizona Newsletter, for the courtesy of permitting use of the article "Pest Control: Monitoring for Insects in Museums," by Nancy Odegaard, MAA Newsletter, Vol 8, No. 2, September 1990, pp. 3-4, as the basis for this article.