No one "right" way exists for controlling, managing or eliminating a particular pest infestation. A number of factors come into play when deciding the best course of action, including type of pest, location, surface type, odor concerns, cost and convenience. Nonchemical techniques are an important consideration in these days of IPM.
Several methods not involving pesticides may be used by service professionals against structural pests. Vacuuming, caulking and exclusion are increasingly being used by today’s professionals; however, the use of traps historically has been the primary nonchemical technique used in structural pest control. But it’s also been the most ineffectively used technique.
How should traps be most effectively used in pest management efforts? How do traps compare in their importance to residual treatments? Is one better than the other? As with all such questions, it depends on the situation. This article will attempt to address the advantages and disadvantages of traps and how they might best be employed.
WHAT’S YOUR GOAL? Traps can be used for two basic goals: population reduction and monitoring. The former goal is identical to pesticide applications in that both seek rapid decline in pest numbers.
Monitoring, however, has different goals. Although the pests captured by a monitoring trap do reduce a population somewhat, the numbers caught result in little impact on the population. A monitoring trap can be used to:
1. Determine if pests are present.
2. Determine the type of pest(s).
3. Determine the infestation’s extent.
4. Pinpoint the infestation’s source.
5. Evaluate the effectiveness of a control program.
POPULATION REDUCTION. Treatments possess the advantage of quick reduction of pest infestations. In fact, for most infestations, the application of one or more residual formulations is the fastest and best strategy to use. Such treatments are more convenient to employ and provide the quick results consumers desire. Also, treatment options are available for most all pest situations. Not so for traps.
As a tool to effectively reduce pest populations, traps are fairly limited to a small group of pests. Rodents are the primary example against which traps are successfully used. Rodenticides are also widely placed for rodent control, but when rats or mice are present, traps are often preferred for quick reduction and a "body count." Capture of rodents in traps provides visual evidence of population control as rodents feeding on a bait often die within their nests or voids. If odors from decaying rodents within walls is a concern, traps are generally considered preferable to baits.
In many cases, both traps and rodenticides are used in an integrated rodent program. Situations need to be evaluated to determine whether traps alone are the best choice or if a combination program would be most effective.
Another group of pests for which traps are used are flies and other flying insects. Of course, insect light traps (ILTs), by themselves may not control such insects to an acceptable level. For example, a building with poor sanitation around the Dumpster, bright exterior lighting, open doors, etc., may allow so many insects to enter that even the best designed ILT program cannot attract and capture enough flies to satisfy customers. In addition to addressing conditions that contribute to insects indoors, targeted residual treatments and fly baits are often important components in flying insect control. ILTs are most effective when integrated into a well-designed program.
Sticky/glue traps can be used to solve limited pest infestations such as a cricket or two in a room or when a wolf spider is seen. The offending pests in these limited situations can be captured, solving the problem quickly and without the need for a treatment, especially where treatments are less desired. Such traps are an important component in brown recluse spider and scorpion programs as each such pest captured is one fewer that could harm a person.
MONITORING. The only equivalent treatment technique to monitoring traps is the use of pyrethrins to flush cockroaches and other insects from their harborages. Flushed insects reveal the type, location and extent of the infestation — the goals of monitoring. But flushing can be time-intensive and is best suited for cockroaches and few other pests (i.e., carpenter ants).
Traps are considered the best choice for monitoring programs and they come in a variety of types and configurations. Commercial monitoring traps are available for cockroaches and other crawling insects, stored product pests, fruit flies, exterior crawling pests and even ants. Monitoring provides information upon which control strategies may be selected. Treatments may be central to success in a given situation, however, nonchemical techniques and attention to contributing conditions are typically included in most situations.
Probably the most effectively used of all monitoring traps are pheromone traps targeted at stored product moths and cigarette beetles. A well-designed Indianmeal moth pheromone trap program is important to many food-processing and storage situations. Such traps can, when properly employed in certain food warehouses, be used as a population reduction strategy.
Conversely, pheromone traps for stored product beetles (other than for cigarette beetles) are often not effectively used. Flour beetles, for example, are not generally responsive to their pheromone compared to the active response shown by moths and cigarette beetles to theirs. Greater thought needs to be given to where and how to place flour beetle traps. Traps used to attract Trogoderma beetles are sometimes located where they can attract these beetles inside from outdoors, thus possibly contributing to infestations. Additionally, monitoring for Trogoderma beetles outside can provide early detection for the possibility of inside infestations. Professionals should consult pheromone trap manufacturers for tips on how to get the most from these valuable tools.
Sticky traps come in a wide variety of types and models. These traps, however, are often placed without much thought. Where cockroach populations are large and easily detected, monitoring traps serve little purpose. Sure, they may catch a lot of roaches, but what do they tell you? Trap captures really don’t significantly impact the overall population and treatments and vacuuming are necessary to reduce the population to the desired level of zero.
Monitoring traps are best used for cockroaches in those areas that are hard to inspect, i.e., motor compartments of equipment in commercial kitchens where the access panel is hard to remove. Placement of a trap in such a location allows the professional to quickly determine if cockroaches have been active in such a site. The presence of cockroaches in the trap triggers treatment efforts; no insects means the compartment can be closed and the professional can move on.
In IPM programs, professionals often place monitoring traps in a myriad of locations. Experiences by some have shown that such wide trap use is generally not necessary. Thought needs to be given to why each trap might be necessary in a given site. Areas where pests are not likely to ever occur or have not previously been reported should not need monitoring traps. A room with a previous pest history but which is not a high-risk area may benefit from one or two judiciously placed traps. Additionally, floor-located traps in commercial kitchens often come up missing or are damaged by water, grease or dirt. Traps in warehouses and storerooms can be rendered ineffective by dust.
SUMMARY. Professionals should keep the goals for the use of traps in mind. Effective and efficient use of traps are an important component for many, if not most, pest management programs. Service professionals should be trained on the advantages and disadvantages of each type of trap they may use. By better understanding their goals in the use of traps — and treatments — they can increase the value of the services provided to their customers.
The author is manager of technical services, Terminix International, Memphis, Tenn. He can be reached at firstname.lastname@example.org.