No, has nothing to do with mold. Insects, there are many that build webbings but likely spiders. Hit the webs with a hard hose spray, or knock those reachable off with a broom. There are insects that can damage your plants however, so pay attention to the plants and if you notice any damage to needles/leaves/branches then the recommendation is to contact a Certified Arborist, one who specializes in everything woody. Find one or more Certified Arborists in your zip code at www.treesaregood.org Click on the Find an Arborist tab. Arborist evaluations are not expensive and where you can learn much about keeping your trees healthy.
Generally however webs are common and usually do not threaten the tree.