I am wondering if you could help me.
The tree out front is presently dripping sap from its leaves. Could this be an insect infestation?
If so what can be done to prevent this?
From your description it sounds as if your tree is suffering from an infestation of aphids. Aphids are tiny insects that feed by sucking sap from the phloem, the food-conducting tissues in plant stems and leaves. These pests secrete a sticky substance called honeydew which is what is dripping from the leaves.
One of our earlier posts details the proper control of aphids:
A strong blast of water from your garden hose can dislodge the adults along with repeated application of insecticidal soap to catch the nymph stages can help control the population of this leaf sucking insect. When spraying with insecticidal soap, make sure to spray both the tops and underside of the leaves.
Natural enemies such as lacewings, and parasitic wasps may help to control aphids, but may not appear in sufficient numbers until aphids are abundant.
If the infestation is severe, you may which to contact a certified arborist to apply the soap. To find a certified professional arborist to help you with a tree problem, visit the Ontario branch of the International Society of Arboriculture here.