Calgary Alberta ... We have a real infestation of Black Aphids on the lower bows of a 30 foot tree. Two people have told us this is a Manitoba Maple. The leaves do not match the description. Irregardless, we are unsure of the best method to deal with these little pests. Winter will soon come and kill them off. This is the first year we have seen them on this tree. They were on a shrub last year. Any advise will be welcome. Jonesy
Hi Jonesy, I realize it's been a long time since you posted, but if you haven't found an answer to your question, I would suggest that you clean up all the leaves if possible. Even if you have snow on the ground, if you get a thaw and can get to the leaves, try removing them and put them out with the trash. If you had mulch under the tree, do remove the top couple of inches and put down fresh mulch when you can. Insecticidal soap is helpful in getting rid of aphids and won't harm the environment or other critters. Newt
This year on southern Vancouver Island the black aphids have been real killers. They've wilted nasturtiums by the bed and have also developed a fondness for Impatiens glandulifera (but they're not stopping the latter species from seeding about) . It is difficult to wash these aphids off without bruising nasturtium leaves, and insecticidal soap seems to be contra-indicated for nasturtiums. I hope that 2006 turns out to be just the peak of a cycle. -Tony
Hi Tony, Cecidomyiid fly larvae are predators of black aphids. Maybe they can help. http://www.umass.edu/fruitadvisor/NEAPMG/63.pdf#search="black aphid + predator" Newt
