black walnut insects?

[minny]

In the TwinCities we have seen insect damage on black walnuts. Woodpeckers are inflicting even more damage.
Hard summer drought. Huge numbers of walnuts.
I'm sure that large numbers of walnuts means excess stress on the tree.
Have you heard of the insect that does this? If so, please reply with the chem name that will control it. How to apply etc.

 

[BC WetCoast]

The large nut crop could be due just to the drought stress.

In regard to the insects, there are several. We need more information. Leaf damage? Boring holes? Twig damage?

There is no 'one insecticide does all".

Identify the signs and symptoms, make the diagnosis and then research the solution.

 

[minny]

Thanks
No leaf damage. No twig or bud damage. There are boring holes. I understand that there would not be a "quick fix" insecticide.
I'm MN Dept of Ag certified pesticide applicator.
Have you or any of your partners seen or heard of this?
Thanks!

 

[lxt]

Boring holes or woodpecker damage? If memory serves me, walnuts produce a chemical that not many insects or even other trees would do well around.

juglone is the toxin im speaking of(just found it couldnt remember), however the pests most commonly associated are: fall webworms, scales, caterpillars & mites.

diseases: brown leaf spot, canker, bacteria blight & powdery mildew!

hope this helps!! Im sure others will provide thoughts as well.

Good Luck!

LXT..............

 

[mckeetree]

In the TwinCities we have seen insect damage on black walnuts. Woodpeckers are inflicting even more damage.
Hard summer drought. Huge numbers of walnuts.
I'm sure that large numbers of walnuts means excess stress on the tree.
Have you heard of the insect that does this? If so, please reply with the chem name that will control it. How to apply etc.

Are you sure it's not gaff marks from spurs?

 

[John Paul Sanborn]

Boring holes or woodpecker damage? If memory serves me, walnuts produce a chemical that not many insects or even other trees would do well around.

juglone is the toxin im speaking of(just found it couldnt remember), however the pests most commonly associated are: fall webworms, scales, caterpillars & mites.

diseases: brown leaf spot, canker, bacteria blight & powdery mildew!

hope this helps!! Im sure others will provide thoughts as well.

Good Luck!

LXT..............

My understanding of juglone is that it is allelopathic, inhibits growth of competitive plants.

Some communities with long term drought have been reporting multi stress related declines in lowland/riparian species.

There's a number of publications online about Walnut Twig Beetle/Canker Complex in the Denver/Boulder area.

In checking this out, I also found that the walnut twig beetle Pityophthorus juglandis is on the invasives list

http://www.dogpile.com/dogpile/ws/r...e/iq=true/zoom=off/_iceUrlFlag=7?_IceUrl=true
http://www.forestryimages.org/browse/subimages.cfm?SUB=15382
http://www.dogpile.com/dogpile/ws/r...e/iq=true/zoom=off/_iceUrlFlag=7?_IceUrl=true

 

[lxt]

My understanding of juglone is that it is allelopathic, inhibits growth of competitive plants.
http://www.dogpile.com/dogpile/ws/r...e/iq=true/zoom=off/_iceUrlFlag=7?_IceUrl=true
http://www.forestryimages.org/browse/subimages.cfm?SUB=15382
http://www.dogpile.com/dogpile/ws/r...e/iq=true/zoom=off/_iceUrlFlag=7?_IceUrl=true

Yes that is correct!! but a side note regarding walnut is that if you have problems with spiders a small walnut log will deter/get rid of them!! I have never tried this though!! I would think if juglone inhibits competitive plant growth it may also have effects on insects.........I dont know...could be an interesting topic!!


LXT............

 

[lxt]

I just found an article by Anthony R, Brach, Ph.D, in regards to Juglone & insects.........It apparently does have some effect on insects, specifically potato bugs, it is actually being looked into as a type of repellent for insects at M.S.U

LXT.................

 

[treemandan]

I have a grove of walnut, very nice, and slightly down slope is a grove of healthy white pine, and smuther norway and a crappy sas ass a frass I try not to cut down.
I am going to let you know if the walnut will keep the spiders out.I wonder how something like this could help driving out the stink bugs.

 

[John Paul Sanborn]

I just found an article by Anthony R, Brach, Ph.D, in regards to Juglone & insects.........It apparently does have some effect on insects, specifically potato bugs, it is actually being looked into as a type of repellent for insects at M.S.U

LXT.................

Interesting, being that potatoes are in Solonaceae, which are most susceptible to Jugone