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Grape vine - larve / insect problem

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[OP]
Jr. Member
Feb 12, 2008
186 posts
29 upvotes
Toronto

Grape vine - larve / insect problem

Hi,

I have this 5 year old grape vine which produces beautiful red grapes. I am posting a few pictures here.

Last summer we watched the grapes grow and turn red and when it was the time to harvest them, we realized that they were infested by worms. All of them. We were utterly disappointed!

What insceticide could we use to avoid that situation in the future? What are some precautions we can take to avoid common diseases of grapes?

Thanks
Images
  • IMG_20200610_1252460.jpg
  • grapes 5.jpg
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Almost all problems in our lives can be traced back to a lack of knowledge.
11 replies
Moderator
May 28, 2012
11924 posts
4526 upvotes
Saskatoon
musicgold wrote: Hi,

I have this 5 year old grape vine which produces beautiful red grapes. I am posting a few pictures here.

Last summer we watched the grapes grow and turn red and when it was the time to harvest them, we realized that they were infested by worms. All of them. We were utterly disappointed!

What insceticide could we use to avoid that situation in the future? What are some precautions we can take to avoid common diseases of grapes?

Thanks
Are the worms on the leaves or in the actual grapes? If they are in the grapes, I would look at getting some gauze/mesh bags that can enclose a whole cluster of grapes....that way you can protect at least some of your crop. They also sell fine garden mesh in long lengths for covering up the plants but it could be quite costly (I use it in my brassica enclosure).

If it's on the leaves, you are going to have to find out what sort of critter is doing the damage. Do you see beetles or caterpillars? If it's caterpillars, you can buy some bt spray at the hardware store. It's organic and perfectly safe for humans and other animals (just not caterpillars).
Sr. Member
Aug 29, 2019
995 posts
453 upvotes
musicgold wrote: Hi,

I have this 5 year old grape vine which produces beautiful red grapes. I am posting a few pictures here.

Last summer we watched the grapes grow and turn red and when it was the time to harvest them, we realized that they were infested by worms. All of them. We were utterly disappointed!

What insceticide could we use to avoid that situation in the future? What are some precautions we can take to avoid common diseases of grapes?

Thanks
Can we see a wide view picture of the grapevine and how it's situated in your yard, so that we can see what's growing around it? The more real life (dont clean it up, show us how it usually looks most of the time) the more accurately we can offer tips.
Sr. Member
Dec 4, 2009
640 posts
621 upvotes
Read up on Malathion, in proper concentrations.
Deal Addict
User avatar
Mar 30, 2004
2523 posts
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Edmonton
Todd96srv wrote: Read up on Malathion, in proper concentrations.
Using Malathion will make the fruit inedible.
The bitterness of poor quality remains long after the sweetness of low price is forgotten....
[OP]
Jr. Member
Feb 12, 2008
186 posts
29 upvotes
Toronto
Katedontbreak wrote: Can we see a wide view picture of the grapevine and how it's situated in your yard, so that we can see what's growing around it? The more real life (dont clean it up, show us how it usually looks most of the time) the more accurately we can offer tips.
Here is another picture. I am training the vine along a wall as I plan to make a vine covered pargola above my deck.
The vine's stalk itself close the fence of my backyard. I have not left any other plant within 1 meter of the vine stalk.
Images
  • IMG_20200709_1048404[1].jpg
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Almost all problems in our lives can be traced back to a lack of knowledge.
Sr. Member
Aug 29, 2019
995 posts
453 upvotes
musicgold wrote: Here is another picture. I am training the vine along a wall as I plan to make a vine covered pargola above my deck.
The vine's stalk itself close the fence of my backyard. I have not left any other plant within 1 meter of the vine stalk.
I meant a picture of the yard (ground). This particular insect winters on the ground. If you can show us a picture of not just the grape vine, but what is planted around it, we can better tell you how to deter these moths. You wont be able to stop the ones coming from neighbouring properties, but you can deter the ones coming from your own yard.

Training a grape along a wall is best if the wall is in full sun. Yours looks to be at least partially shaded, which attracts bugs. Best to trellis it over your future pergola and away from the wall.
[OP]
Jr. Member
Feb 12, 2008
186 posts
29 upvotes
Toronto
Katedontbreak wrote: I meant a picture of the yard (ground). This particular insect winters on the ground. If you can show us a picture of not just the grape vine, but what is planted around it, we can better tell you how to deter these moths. You wont be able to stop the ones coming from neighbouring properties, but you can deter the ones coming from your own yard.

Training a grape along a wall is best if the wall is in full sun. Yours looks to be at least partially shaded, which attracts bugs. Best to trellis it over your future pergola and away from the wall.
My yard is is big lot (70' x 40'), but mostly grass, with some weed. I had two vegetable beds, but I am converting the one close to the vine stalk back to grass.
The yard also has a big maple tree, whoes shadow sometimes cover the vine.
Images
  • IMG_20200709_1553528[1].jpg
  • IMG_20200709_1554217[1].jpg
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Almost all problems in our lives can be traced back to a lack of knowledge.
Sr. Member
Aug 29, 2019
995 posts
453 upvotes
musicgold wrote: My yard is is big lot (70' x 40'), but mostly grass, with some weed. I had two vegetable beds, but I am converting the one close to the vine stalk back to grass.
The yard also has a big maple tree, whoes shadow sometimes cover the vine.
Be sure to rake up any fallen leaves or dead plants near your grape vine before winter so that the moths cannot over winter near your vine.
[OP]
Jr. Member
Feb 12, 2008
186 posts
29 upvotes
Toronto
Katedontbreak wrote: Be sure to rake up any fallen leaves or dead plants near your grape vine before winter so that the moths cannot over winter near your vine.
Thanks. Is there any chemical I can spray to make sure that bugs don't rot the fruit or keep them away?
---------------------------------
Almost all problems in our lives can be traced back to a lack of knowledge.
Sr. Member
Aug 29, 2019
995 posts
453 upvotes
musicgold wrote: Thanks. Is there any chemical I can spray to make sure that bugs don't rot the fruit or keep them away?
BT (for caterpillers), but it requires some frequency from preventing entry into your grapes. You have to spray while the grapes are small and newly emerging, so that you can get the spray saturated around the grapes before they start growing into each other where spray wont be able to be applied well on a thick cluster of grapes.

The cycle of this moth is important so you need to be dilligent.

Cycle 1 moth pupae will winter on fallen debris and long grass around the vine in the fall. Ensure you cut the grass short and throughly rake up any leaf and yard debris (doing so to the whole yard would be ideal so they don't winter anywhere on your property.

Cycle 2 moth will form in early spring and lay eggs on your grape vine. Watch your grape vine for any insect webbing, eggs and cocoons on the buds and underside of leaves. They are typically very small white-yellow specs. Manually remove them and drown them in soapy water or try a spray like Safer's End All. You will see evidence of the caterpillers eating holes into the leaves when they emerge. If these caterpillers pupae into moths, you get the 3rd cycle that will enter the grapes in the summer.

Cycle 3 (you are currently in this cycle) moths will lay eggs on the vine close to the emerging grape clusters. You will have to spray these emerging grapes on a regular basis as the caterpillers emerge and try to enter the grapes. If the caterpillers successfully enter the grape, spraying will not work. The grape protects the caterpiller inside from the BT. Breached grapes should be removed and bagged for garbage so the caterpillers do not get a chance to pupae near your vine. Typically what happens here is after the gourge on the grapes, they will crawl down into the grass-weeds-yard debris around the vine and pupae for winter and the cycle repeats itself from cycle 1. You have to try and destroy as many eggs, pupae, caterpillers and moths in each cycle as possible.

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