Hello,
I live in Calgary Alberta. We have a huge fir in the yard. I'm not sure what kind. Some of the new sprouts on the tree get infected every year; they expand, turn lightgreen/pink and finally they dry out and turn brown. In it there are what appear to be leaf miners; small redbrown mites with black droppings and white cobweb debris. There are several of them in little seperate rooms within the sprout. Every now and then I find a green caterpillar as well. Next to the tree is a birch that is also affected. Can firs get affected by the same bug ? Can I use the same treatment for both (dimethoate) ?

Thanks for any advice, Steffen.

Reply to post by Steffen, on August 06, 2002 at 19:25:45:

The quality of advice can depend upon the information provided. You are unclear about whether the tree is a pine or some kind of fir species. I suggest that you find a good local arborist or forestry expert to come have a look. Nothing can beat a first-hand inspection. A local problem may also be better known by local experts.

Start by finding out what tree you have, then it will be easier to find probable pest information. Treating problems with pesticides is irresponsible unless you know exactly what you are treating for. Ask for complete and verifiable information from whomever you hire to help you.

I have included a link to a canadian site that might serve as a starting point in your search for understanding.

Reply to post by Mark Goodwin, on August 06, 2002 at 19:25:45:

Well, Mark is absolutely right.
The pesticide you mentioned will definitely kill the pests - dimethoate (usually used in 400 g. per l. concentration) will kill any insect that get into direct contact with it and then it'll kill those, who eat the treated plants (this preparation has system effect - it spreads by conductive tissue).
Birds and entomofagoes will eat the poisoned insects and will suffer.
So, this preparation is nonselective and very dangerous for mammals (it has cumulative and mutagenic effect) pesticide.
Waiting period is 40 days! (it means you can't eat any treated fruit during 40 days).
You can't walk near the treated trees during 10 days!
You will solve the problem, but you will also create several new problems.
I wouldn't use that in MY yard.