Grape Vine Pests

[Somtham]

Yesterday I noticed that we have out first bunch of grapes on vines transplanted 2 years ago. Very exciting but...there is also something eating the leaves. Whatever it is can wipe out most of the leaves on a vine in a single day. From the appearance of the leaves in the pic can anyone identify what might be eating the leaves and possible treatment to eradicate them?

Thanks

[Cavannagh]

More information?

Some of those spots and discoloration in the leaves make me think spider mites...but I can't imagine those little critters doing that much damage in a single day. Are there any small, silky webs around the stems? Also check the underside of the leaves where they congregate and lay eggs.

Hmmm...if you are not seeing the pests yourself then you are probably looking at some sort of larger, swarming insect.

Edit - I should mention I'm an amateur gardener and have never farmed in Thailand

Edited April 1, 2008 by Cavannagh

[Somtham]

More information?

Some of those spots and discoloration in the leaves make me think spider mites...but I can't imagine those little critters doing that much damage in a single day. Are there any small, silky webs around the stems? Also check the underside of the leaves where they congregate and lay eggs.

Hmmm...if you are not seeing the pests yourself then you are probably looking at some sort of larger, swarming insect.

Edit - I should mention I'm an amateur gardener and have never farmed in Thailand

Thanks for your reply. I don't see any silky webs or eggs but whatever it is left some poop behind last night on the tops of the leaves.

rgds

[Cavannagh]

Tough one....sorry I can't be much help.

I think "sticky traps" are going to be your best bet at identification. If you can't get hold of any commercial types then just make them yourself.

- Find some scraps of thin, wooden board or some similar material which can handle the elements. Something about the size of a playing card...maybe a bit bigger.

- Paint them bright yellow and pierce a hole on top, thread some string or wire through the hole so they can be hung around branches.

- Apply a thin coating of grease or motor oil to both sides of the yellow 'cards'

- Hang them up for a couple of days and see what you get.

(Painting them yellow will help attract the insects)

If you can, try and remove as much of the droppings as possible because they can become mouldy at attract more insects/bacteria. If you can make a good "organic compost tea" and do a foliar application it will help breed beneficial bacteria and predatory nematodes, this will help contain any secondary problems. Whatever is attacking those plants is making them weaker and suseptible to more disease/attacks.

[meandwi]

That is caterpillar damage. There is many safe soap based insecticides on the market to help control them.

Good luck,

meandwi