Stored food insects communicate with each other using different types of pheromones. It is common practice to monitor food storage areas and food manufacturing facilities with traps using lures containing these compounds. The decision to use pheromones for monitoring stored food insects, however, is often based on a person’s level of knowledge about their use. For many it is still an untried or misunderstood technology that has been available for more than 20 years.
To successfully use these devices, one must work with four elements that have a significant influence on trapping results. They are the pest, the pheromone lure, the trap type, and the location or placement of the trap. The starting point and most important element to understand is the insect. The biology and behavior of each species limits the choices and placement of trapping systems.
The red flour beetle, confused flour beetle, saw-toothed grain beetle, merchant grain beetle, rice weevil, maize weevil, and granary weevil (S. granarius) are insects that predominately crawl from one food source to another. The red flour beetle, merchant grain beetle, rice weevil, and maize weevil, can fly, but rarely indoors. To monitor these pests in large facilities:
1.Do not use hanging traps to capture crawling stored food beetles that rarely fly. Do use
pitfall traps like the New PC floor trap™, Dome Trap™, and Pantry Patrol trap™. Sticky
blunder traps can also be useful.
2.Weevils and grain beetles are more mobile than flour beetles. Place traps for flour beetles 10-15 feet apart and up to 20 feet for the other species.
3.Flour beetles are more active in the dark and occur in patches near food and harborage. Traps should be in more secluded undisturbed areas such as corners, behind posts, under shelves, gondolas, at the base of racking systems, near cracks and crevices, and in dimly lighted areas where food accumulates.
4.Grain beetles are more mobile but tend to follow crevices and edges, so place more traps accordingly near these sites.
5.Weevils are the most mobile when searching for food and can spread in all directions so traps can be more widely placed (e.g. 20 feet).
6.Beetle traps should be in targeted locations such as near food storage and harborage sites or areas of high risk to infestation. Standard grid placement (e.g. every 15 square feet throughout a building) results in many traps with poor catch. Better time can be spent on traps with a high chance of capturing insects.
by Alain Van Ryckeghem, BCE Technical Director