On Sat, 18 Jul 2015 08:46:06 -0400, Norminn
wrote:

On 7/13/2015 9:44 PM, passerby wrote:
This year the Japanese beetle situation in my backyard here in SE PA is
simply dire - I have just disposed of the nine's bag, which probably gets
the total close to 12-15 pounds of bugs so far, and they keep coming! The
usual amount is perhaps 3-4 bags a season, and usually I don't dispose of
them because they are overflowing like this year, only because they start
smelling awful. This year I've also sprayed heavily, so the amount of bugs
killed is staggering, yet they keep coming.
It just so happened that I put the first two traps up maybe a week in
advance of actually seeing the first bug. This got me thinking that
perhaps I have brought this on myself by attracting the first bugs by the
lure of the traps? And then the consequent waves of bugs are just
attracted by the previous ones? Has anyone seen use of Japanese beetle
traps to actually increase the amount of bugs?

I should add that I don't really have a place to put them 30 feet away
from the yard, like the description on the trap calls for, I have some
oak trees about 10 feet or so from the property line, and that's the
farthest I can put the traps. Regardless, the leaves are destroyed in
close proximity to the traps as well as some 30-40 ft away.

So, what's the word on usefulness of the traps in the gardening community?

I tried traps years ago, in Indiana. The results were amazing, as I
could see dozens of JB's in flight across surrounding yards. It was
like LaGuradia the day before a holiday! I later read that they are not
really effective, and DO attract beetles unless the neighboring yards
also use traps. But, then, how far out is "neighboring"?

No matter where one places traps one will be sacrificing some plants
in an attempt to save others. Japanese beetles are fairly selective
in which plants they eat, so it's most effective to spray those
trees/shrubs where beetles are active. Five years ago there was a
heavy infestation of Japanese beetles here, lots of people set out
traps including me. I live on several acres but regardless where I
set the traps the beetles found certain trees and shrubs, they loved
my lindens, fruit trees, and roses. Finally I mixed up a batch of
sevin for my hand sprayer, the beetles departed or died but within an
hour all were gone. If one follows the directions sevin is safe. All
my neighbors agreed, the traps increased the infestation while
relatively few beetles died in traps.