Monitoring for pest activity is a critical aspect of a well-developed proactive IPM program. There is a wide variety of monitoring programs and devices; unfortunately, many of the devices are thought of as control devices rather than alert systems. Monitoring devices can collect information critical to your decision-making process. Pest identification allows you to know exactly what you are dealing with and how you should approach a solution. Knowing where the devices are located is also important. This requires a clear and accurate map of where the devices are placed within the plant or warehouse.
Insect Light Traps (ILT).
Insect light traps are used to determine the types of flying insects entering the facility. They are not, however, limited to attracting only night-flying insects or house flies. They also attract many species of stored product insects, such as cigarette beetles, warehouse beetles, Indianmeal moths, and others. It is important to not only monitor how many are trapped, but also identify what is captured. For example, stored product pests captured in ILTs can be an early warning of a developing infestation.
Inspection of the devices should be conducted on a weekly basis during warmer months when insects are most active. The inspection schedule can be reduced to monthly in cooler months due to the lack of flying insect activity. In areas where there is extreme cold, some facilities choose to suspend inspection of the devices during these periods. However, the temperatures inside the facility may not change significantly, so though there may not be exterior flying insect issues, there is a possibility that stored product insect activity may still be present. ILT monitoring frequency in extreme cold areas should be based on a facility’s history of pest activity. Regardless of the climate you are in, follow the bulb manufacturer’s recommendation on when the bulbs require changing.
Pheromone traps can be an important element of an IPM program depending on the type of insects that are of concern. Most insects use chemistry (pheromones) to communicate instead of sound. They have sex attractants to enhance successful reproduction, dispersal, aggregation, and other communication pheromones. Pheromone traps replicate these naturally occurring insect pheromones to attract insects to the devices.
Insects that have a short adult life span and are very mobile with the ability to fly are most drawn to sex attractant pheromones. The sex attractant for the cigarette beetle, warehouse beetle, and Indianmeal moth are the most common sex attractant pheromones being used in the food industry. They are very effective at detecting early stages of activity of these insects and, when used properly, can help locate the source of the activity. The pheromones used in these devices are specific to the insect, with each pheromone being species specific.
Trap usually are placed in a grid pattern taking advantage of structural supports or the racking system to for placement in accessible areas. Since aerial traps address flying insects, there is no need to place pheromone traps up high. Placement at eye level at distances recommended by the manufacturer is more than adequate.
Investigating an increase of activity may require using more traps rather than just a routine monitoring program. The extra traps are used to help pinpoint the source of the infestation so it can be dealt with in an appropriate manner. Once the source has been identified and resolved, the extra traps can be removed.
Placing all the traps on a location map for quick location during trap inspections is an important part of the program. The information collected from the traps provides data for trending analysis used to determine the overall effectiveness of your control efforts. These traps help determine whether the number of insects is increasing, decreasing, or remaining the same as a means to assess your IPM program.
Glue Boards or Other Sticky Traps.
Glue boards and sticky traps are used to monitor crawling insects and some rodents, such as mice. These devices are typically placed around interior perimeters within a facility and sometimes within a mechanical rodent control device. It is best to install some type of shelter over these glue boards or sticky traps to prevent dust and other materials from accumulating and decreasing their effectiveness.
Glue boards can be used to capture rats, but extra measures may be necessary as the rats can escape if all four feet are not stuck to the glue board. It may be necessary to secure the glue board to a piece of cardboard several inches larger than the glue board or to secure it to the floor to prevent rats from dragging the board around the facility before dying.
These devices should be monitored at least weekly and the findings documented on a monitoring record to be used for trending analysis. Any devices with significant amounts of insect activity or any rodents should be removed, replaced, and properly discarded.
Bait stations are rodent monitoring devices placed around the exterior perimeter of buildings at appropriate intervals. Rodenticides or monitoring blocks are placed inside the units. Rodents are attracted to the bait stations as a place of shelter that allows them to feed on the baits in a dark, enclosed, and protected area. Rodenticides used inside the stations are lethal and designed to cause death within a few days of consumption.
Bait stations should be properly positioned at appropriate intervals based on the facility assessment. The purpose of the placement is to match typical rodent behavior and allow IPM professionals to monitor rodent activity levels by examining the amount of consumption of the rodenticides or monitoring blocks. Monitoring blocks do not contain any active ingredients and are designed to simply monitor rodent activity.
Bait stations should be installed by anchoring them to the ground, securing the covers, and securing the bait inside of the stations. All bait stations used in the food industry must be tamper-resistant.
The stations should be inspected at least monthly, and more frequently in high rodent activity areas. Consumed or deteriorated (moldy or wet) baits should be properly replaced and a record made of the service and activity levels.
Mechanical Rodent Control Devices.
Mechanical rodent control devices are primarily used for monitoring. Rodent capture informs the plant of pests entering the facility and should trigger an investigation to determine how the pest entered and if there are more to be concerned about. Many of these devices can have a glue board installed in them that make it easier to clean and remove a dead rodent, but they also provide an opportunity to use the traps as an insect monitor. Mechanical rodent control devices may include mechanical traps or extended trigger traps.
The devices should be installed around the interior perimeter of the facility and on both sides of exterior doors. The spacing should be based on the facility assessment. The devices should be checked at least weekly and any findings should be documented on a rodent control log before the device is cleaned to remove rodents, dust, or other evidence of rodents such as hair or droppings.
The author is technical writer, AIB International.