Alan, that is a good link, but it is outdated and restrictive on its control suggestions, as extension pubs often are. Research printed in 2 arb journal articles, one in the '90's and one just last year, found that smothering with pruning paint and caulking was at least as effective as using the wrap, with less damage to the tree. Also cheaper and less ugly.
rb, if the guy likes his trees he should be willing to pay an arborist for a visit. I'll bring the caulk for the mistletoe, and do what's right for the maple too. pm me if you want a cv to fwd. I'll charge more than i did to move those boxwoods (most of which lived!), but less than what I'm worth.
It's funny they say Bradford pears are resistant; ours here in NC can be choked with the stuff. Below is their cutfirstandaskquestionslater approach.
The most effective way to control mistletoe and prevent its spread is to prune out infected branches, if possible, as soon as the parasite appears. Using thinning-type pruning cuts, remove infected branches at their point of origin or back to large lateral branches. Infected branches need to be cut at least one foot below the point of mistletoe attachment in order to completely remove embedded haustoria. Done properly, limb removal for mistletoe control can maintain or even improve tree structure. Severe heading (topping) is often used to remove heavy tree infestations; however, such pruning weakens a treeís structure, and destroys its natural form. In some cases it is best to remove severely infested trees entirely because they are usually a source of mistletoe seed.
Mistletoes infecting a major branch or the trunk where it cannot be pruned may be controlled by cutting off the mistletoe flush with the limb or trunk. Then wrap the area with a few layers of wide, black polyethylene to exclude light. Use twine or tape to secure the plastic to the limb, but do not wrap it too tightly or the branch may be damaged. In some tree species callus tissue will form under the plastic, further weakening the limb. Broadleaf mistletoe requires light and will die within a couple of years without it. It may be necessary to repeat this treatment, especially if the wrapping becomes detached or if the mistletoe does not die.
Simply cutting the mistletoe out of an infested tree each winter, even without wrapping, is better than doing nothing at all. Even though the parasite will grow back, spread is reduced because broadleaf mistletoe must be several years old before it can bloom and produce seed.