It has been said that using the pheromone- based traps to capture japanese beetles ultimately attracts more of these pests to your area. I have also had the experience that these lures are extraordinarily effective at attracting huge numbers of beetles, and have been doing some practical research on the use of these traps. I would like some comment on the following: Is it true that, overall, these devices just attract more beetles to your area? If so, what would it take (numbers, for instance) to tip the scales in our favor? How many beetles would one (or a group of) homeowner(s) need to capture to make a difference? A thousand per day? Ten thousand per day? More? I'm very interested in finding out more about this. Perhaps there's someone I could meet to discuss this in more detail.

Dear Mr. Burdin:

The suggestion that Japanese beetle traps increase the amount of damage near to them is based on high quality research conducted several years ago.

Although many beetles are trapped, many more are attracted to the area than trapped. Many of the beetles are not attracted all of the way to the trap, feeding on nearby plants instead.

The number of beetles that would need to be trapped to reduce damage in an area cannot be calculated. That is because the number of beetles vary greatly depending on the amount of turf in the area for the larvae to develop on, the amount of moisture in the fall, the amount of freezing in the soil during the winter and how long it lasts, the number of trees and shrubs in the area available for the adults to feed upon, and probably several other factors.

It is more appropriate to determine the area that would need to be trapped to significantly reduce damage. Every three days, the beetles change hosts, flying 3/4 to 1 1/2 miles to new hosts. With the beetles being present in high numbers for about 6 weeks (42 days). With the beetles flying every three days, 42 divided by 3 equals 14 flights. 14 flights times 3/4 to 1 1/2 miles equals 10.5 to 21 miles. This corresponds nicely to surveys shortly after the Japanese beetle became known in this country in New Jersey in 1916. It was recorded that the beetle was spreading at the rate of about 15 miles per year. An area with a 15 mile radius would need to be heavily trapped to significantly reduce the amount of beetle feeding. This is 706.5 square miles. For size comparison, Champaign County is about 1200 square miles.

If you could get the residents of an area the size of half of Champaign County to do anything together, you could probably rule the world.

Sincerely, Phil Nixon