From what I have been able to find, the only feasible controls of leafminers are parasitic wasps, such as the Tricogramma, and encyrtid wasp, Ageniaspis citricola, and the eulophid wasp, Cirrospilus coachellae.

I need to aquire some of these and get them out at the best time. So, what would be the best time to put these wasps out in the garden?

You are farther south than I am, here we put out the wasps just as the trees are beginning to leaf out. Maybe the wasps would hatch & freeze b/4 then?? So in your area...perhaps it wouldn't matter??

Patty

As you may already know from researching the Trichogramma wasp, when you buy them they are still in egg form. The instuctions will be to either open the box and put on the ground or in a tree or pin the piece of paper that has the eggs on it, to the trunk of the tree. Anyway you do it, the wasps should emerge in about a week. I heard that this should be done just as the leaves are emerging in spring. I would say early March maybe?

Also look at the link below which you can find by going to the main pae and clicking on Library, then "T" for Trichogramma.

http://www.dirtdoctor.com/view_question.php?id=1082