Food Safety Magazine, June/July 2009

thrive. External inspections should focus on historic infestation problem areas at the facility and areas that are conducive to infestation. Internal inspections should focus on key areas within the facility that promote pest infestations as well as maintenance issues.

The scope of the IPM program will be based on the findings during the facility inspections that will help to determine the control tactics necessary for the pest causing the infestation.

Correctly identifying the target pest is essential to control; it enables pests to be eliminated more effectively and efficiently. Specific pest control tactics should be based on a thorough understanding of the pest’s biology and behavior, thus limiting its ability to survive. For example, distinguishing between a mouse and a rat will help to determine the best method of control. The following lists common pests that represent a high percentage of pest situations in the food and beverage industry:

• Rodent identification: house mouse, Norway rat and roof rat.

• Bird identification: European starling, English sparrow and pigeon/rock dove.

• Insect identification: house fly, fruit fly, stored-product insects (e.g., beetles and moths), ants and cockroaches.

A pest action threshold is the point at which pest populations or environmental conditions indicate that pest control action must be taken. The action threshold includes constant monitoring for pests and determining if and when control is needed. Thresholds for the four inspection zones will be increasingly stringent as more pest-sensitive areas are addressed.

Continuous monitoring of the facility for pest activity and operational changes that affect pest management will help to protect against infestation and eliminate existing pests. Identifying the signs and symptoms of infestation is critical to successful monitoring and can enable detection of activity before a visual confirmation is made.

For rodents, gnawing and teeth marks are common indicators of activity. Rodent droppings are often found with gnawed materials and can be confused

with other droppings, including those of cockroaches and lizards. Proper identification of droppings will assist in accurate identification and monitoring activities. For example, all rodent droppings contain hair, but Norway rat droppings have blunt edges and roof rat droppings have pointed ends. Other signs of rodent infestation include burrows, digging and rub marks. As part of ongoing monitoring for exterior rodent activity, bait stations (with non-toxic baits), glue traps and other devices should be opened and inspected on a set schedule.

Control is necessary when signs of infestation have exceeded a pre-determined limit known as the “action threshold.” Action thresholds are pest-specific and must take into account both internal and external pest infestation. Some examples of observations indicating that an action threshold has been achieved for common food and beverage industry pests are listed in Table 1.

It is important to control and evaluate a pest situation when monitoring, identification and action thresholds indicate that pest control is required, is no

The action threshold is achieved when any of the following is observed:

Rodent Bird Insect

Exterior • A physical sighting • Bird nests • Insect mounds/nests

• Evidence of damage • Evidence of bird damage • Evidence of damage

to the facility to facility to the facility

• Other unacceptable

activity levels

Interior • A physical sighting • Evidence of damage

• Bird droppings to products or facility

• Bird nests • Insect mounds/nests

• Evidence of bird damage • Other unacceptable

to products or facility activity levels

Table 1: Action Thresholds for Common Food and Beverage Industry Pests

• A physical sighting

• Droppings or urine

• Evidence of damage to products or facility

Due to the nature of bird infestations, monitoring for birds is a manual task. Some signs and symptoms that may indicate bird infestation include nests outside the facility, evidence of bird damage to the facility, and bird droppings at potential entrance and exit areas and at potential feeding and watering areas. Further evidence of bird infestation includes nesting materials in rafters and in corners of the warehouse, evidence of bird damage to products, or droppings on products.

Monitoring for insect activity requires multiple approaches. Look for insect trails, colonies and nesting sites such as potted plants, under slabs or in wall voids. Outdoor nesting sites may be under stones, boards, and similar objects near the facility. Regularly monitor insect control devices such as glue boards or fly lights for evidence of an increase or decrease in types and numbers of insects. Monitoring with insect pheromones is a cost-effective tool that can provide early detection. Pheromone traps should be placed on a map or grid to identify areas of infestation.

longer effective or not available and preventative methods should be implemented. A sequence of events needs to take place to ensure effective control. These include understanding the control options available, developing an action plan, executing the plan and evaluating the results for effectiveness.

In most cases, there is more than one option available to control a pest infestation. It is important to understand all of the options that are available, with a focus on targeting the vulnerability of pests to keep them from returning. One must consider both the benefits of cost and the effects on the environment to ensure the appropriate use of control measures for the appropriate targets. Controlling pest infestations can be achieved by using the following three principles: