In other years, when the adults were active, I found insecticidal soap was the only effective option. They are very resistant to any type of pesticide.

patrick113, thanks for your advice. unfortunately I never did get around to checking into much of it. I don't think traps would work, if you could see the magnitude and multitude of this invasion you would be sickened. (well, they would work, but not enough I wouldn't think.) I still plan on talking to the UW-extension people, but I have a little more insight into this problem since a year ago this time, and hope my timely spray schedule coupled with advantageous weather will do the trick..

Capoman, I still would like to look into the pros and cons of BT. Problem is that my neighbors property directly adjoins my orchard, I will have to convince him of the necessity of an application as well. I had some left over Sevin in the sprayer the other night and asked if he would like me to spray some of his trees, he only has a few. He was glad to show me his trees, and even happier to have me spray them when he saw what the chafers were doing to them. His highbush blueberry was decimated, I am talking skeletonized leafs from top to bottom and so many chafers you could hardly see the branches. I think he may now be convinced of the necessity to dispatch this miserable vermin. Thanks for the advice guys!

Have you had Japanese Beetles show up yet? I've had JBs for about 3 years now. First year just a few and then bam... I find them more destructive then chafers (which i have too). It never ends with pests here. PC were horrible this year. And of course Squirrels, birds, humans, aliens...

One good way of watching when these pests come out is to follow growing degree days. There are lists out there that show when various pests emerge/etc.

Last year i had very little PC damage and this years its unbelievable. I have no apple crop because they put about 20 egg laying marks on each apple in what was a very tiny crop to begin with.

I don't have fruit trees, hardly a garden (yet?) but read everything here on GW; I also had really bad experience this year with rose chafers (just moved to new location). Soil here is very sandy, and property has nothing but grass. This is my first experience with rose chafers - they totally decimated few potted plants/shrubs I have.
I read that they are poisonous to chickens; so keep your chickens away. Birds don't eat them either.
As I said, I only read that, but every site that I checked said same thing.
I didn't find any warning about grubs...so that may be OK for chickens.

Rina

I typically spray my trees with Sevin, as it contains Carbaryl that kills the chafers. I am worried about the overspray or contaminated bugs the chickens might eat. We were referring to the grubs that become the chafers, and the options for controlling them before they emerge.

if I may - here is what I learned:
*they really love sandy soil to lay their eggs in
*grubs feed on grass roots and roots of non-crop plants
*grubs travel deep (4' or more) for winter
*adults live approx. 6weeks
*cultivate soil few weeks after eggs were deposited into soil - some remaining eggs will be destroyed, young grubs too
*add organic matter
*cultivate in spring to destroy grubs before they emerge as adult beetles
*spray soil with beneficial nematodes (they feed on grubs-also other grubs like jap.beetles)
* treat with garden insecticide (contact or systemic; carbaryl is contact & residual 10-14 days; imidacloprid is systemic & residual up to 4weeks - there are few other)

franktank, I didn't know about wood chips...

more here:
https://archive.org/stream/jstor-1640622/1640622_djvu.txt

...An extract was made from
crushed rose chafers and distilled water,
filtered, and fed to chickens in varying doses
with a medicine dropper and this resulted in
a great many deaths. Small chickens died in
a few hours after feeding, older chickens of
heavier weight when fed a small quantity of
the extract lived but showed signs of poison-
ing; large doses resulted in their deaths.
Mature hens did not die from the extract.

From 150 to 200 chickens have been fed
either with the rose chafers or with varying
strengths of the extract to determine the
weight of the chicken killed by a certain
amount of poison, also to determine the age
limit of the chickens killed.

The results may be summarized as follows:
15 to 20 rose chafers are sufficient to cause the
death of a chicken one week old. From 25 to
45 rose chafers are usually necessary to kill a
three-weeks-old chicken. While some nine-
weeks-old chickens have been killed by eating
rose chafers, only one ten-weeks-old chicken
was killed in these experiments. In the crop
of this chicken there were 96 undigested rose
chafers counted in post-mortem examinations.

The chickens feed upon the insects raven-
ously, being attracted by their sprawly ap-
pearance and usually within an hour after
eating they assume a dozing attitude, later
leg weakness shows and the chicken usually
dies within twenty-four hours of having eaten
these insects, or begins to improve after this
time...

Rina

I also read how they have an affinity for clover patches....arggggghh! maybe I wouldn't have planted my orchard rows with red and white dutch if I had known that, but it makes such a lush and pretty carpet....

I read that report also, I think it was from a 1916 article, but it seems to be on par with what all the other more recent studies are saying.

I didn't see the info about the clover - that is what I was hoping to do (white clover) instead of grass (or chamomile).

I am seriously considering the beneficial nematodes. But, it is also 5ac, and that is a lot. Not sure if anything would grow here unless I use nematodes+++, look what they did to few young trees I have in pots - completely defoliated, today I found some new leaves starting to grow...

Rina

I think I weathered the storm pretty good this year, though I hit the trees every seven days with carbaryl for four sprays, now starting to lay off the spray and all seems well. I did have a few skeletonized leaves, but the trees looked good overall.

I would plant the clover anyways. I have really enjoyed seeing the deer and rabbits out my 10 x 5 ft picture window. My daughter also likes watching them. Of course she says "Daddy! Shoot'em n eat'em! Bang!" then she runs off to find her squirt gun :) That's my girl.

I have some grapes started from cuttings, they were in different location so were not attacked, but I believe that's one of their favoured.

I have clover seeds, so most likely will plant it. There is some growing (white) by the barn, I am watching 2 'baby' bunnies lounging in it every day...they are cute (so far!!!)

Rina