This pics are for my dad. Today we found his Hawthornes infested and thanks to my macro lens I should be able to learn what they are and figure out the best plan of action. First order of business is to properly identify the pest. These appear to be a type of larvae, but the larvae of what I do not yet know.
Next will be to figure out the life-cycle of the pest. This helps because depending on the pest there are different times during it's life-cycle that it is most vulnerable, and that is when you want to treat the affected tree.
Because these critters were found everywhere my hope is that the tree is not so infested that it has to be removed. To give you a sense of scale the branch in the above picture is only an inch or more in diameter so these critters are pretty tiny. For those in the plant world they looked like big, black thrips, though I know that's not what these are. Anyway, time to break out the reference books.