The Do’s and Don’ts of Trapping Beetles: Part 2

Both sexes of flour beetles, grain beetles, and weevils are attracted to aggregation pheromones and food odors (kairomones). Pantry Patrol™ traps use a no spill gelled oil food attractant combined with aggregation pheromones of flour beetles (among several other species). Dome traps use food oil attractants and separate pheromone lures for flour beetles. The dome is a good cover for dusty areas. The new PC floor trap only uses a food attractant, but the trap keeps the captured beetles alive, thus allowing natural pheromone to be emitted from the beetles in the trap. The PC floor trap is especially effective with the grain beetles. Unfortunately, there is no commercial pheromone for the saw-toothed and merchant grain beetles available yet. The weevils seem to be caught easily in any of the traps. Some weevil pheromones are available and can improve catch compared to food attractants only. Flour beetles are more selective based on pheromone concentration, and trap design/placement. In places where competing food is available (e.g. flour) the trap catch can be dramatically less. Sanitation improves catch as the beetles are more starved and need to search further. To monitor for pests in food product or for locating structural infestations:

7. Use traps best suited to the target beetles.

8. Use lure/ food combinations that are most attractive to the target beetles.

9. Place traps in covered stations if necessary for dust and people protection. Flour beetles are very poor climbers and the covered station may prevent access to the traps. Choose a
design that has holes flush to the floor.

10. Map your traps so that you can account for them. Lost traps mean no data and possibly
problems if they end up in the “food channel.”

Cigarette beetles (Lasioderma serricorne), drugstore beetles (Stegobium paniceum) and warehouse beetles (Trogoderma variabile) are much more active. They are good fliers, can be found outdoors as well as indoors in the southern states and are attracted to light. The females produce sex pheromones, which unlike aggregation pheromones attract only the
male beetles and can be detected from more than 25 feet. Presently the pheromone for drugstore beetles is limited in the US. Cigarette and drugstore beetles will fly when the temperature is above 70°F(21°C) while warehouse beetles fly when it is above 65°F(18°C).

For these beetles:

11. Use sticky hanging traps like diamond, delta and wing traps with a good pheromone lure for monitoring large warehouses.

12. Flat sticky traps with lures and floor traps like Pantry Patrol and Dome trap can be used for smaller areas like grocery stores and residential kitchens.

13. Replace lures according to manufacturer (4-12 weeks depending on type).

14. Date your traps to indicate when the lure was installed.

15. Remove beetles from the traps to make counting new beetles.

16. Replace traps if they are 50% filled or more.

17. Do not place traps with these pheromones within 30 feet of an outside door or exterior window to reduce the opportunity of immigration from outside.

18. Document the number of newly caught beetles on a separate record/report.

19. Adding a sex pheromone lure to a light trap can attract males and females to the glue traps.

20. Using pheromone traps in a trap line outdoors about 50 feet away can monitor the outdoor population and indicate if indoor catches are from beetles entering the facility from

Trapping stored food pests takes time, patience, and knowledge. The data you collect can help you understand the dynamics or origin of a population inside a commercial facility or even a residence. The best way to learn how to use these systems is to try them in one
account on a small scale. Let the customer know what you are doing and what you can expect to gain in terms of timely or reduced pesticide applications. You can also evaluate the effectiveness of your pest management program by looking at the numbers. Gathering
this data is a way of gaining knowledge and experience. Before long you will be comfortable with their use and know what to expect.

by Alain VanRyckeghem, BCE Technical Director


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