When I get calls about unusual indoor pests at this time of year. I consider Christmas trees, holiday wreaths and other fresh greenery as a possible source. There are two types of Christmas tree pests. The first are those that feed on Christmas trees in the field and are problems for the tree growers such as red spider mites, spruce needle miners, spruce budworms, pine needle scales and bagworms. Aphids and spruce spider mites are the two most common Christmas tree pests found on trees. White pine aphids are small black insects that customers might find crawling on their pine trees and ornaments. These pests that feed on the tree should have been eliminated by the grower before the tree is harvested.
Gowers say pests are rare on for sale trees and that only 1 in 100,000 trees would have pests. But of course, if someone cuts down his own tree or greenery, all bets are off. The second group of pest are miscellaneous insects that have moved into the Christmas tree, usually to seek shelter or overwintering spots. Trees can even acquire pests after harvesting during transport or storage on the lot. These hitchhiking pests are some of the same pests that can be carried in on firewood like spiders, Beatles, and ants. These insects will remain quietly in a tree that is outside but when you bring it indoors, they warm up and become active again. Praying mantis eggs cases are commonly found on Christmas tree branches and will sometimes hatch indoors. The case looks like a chunk of beige Styrofoam. Just prune it for control. The main thing is to remain calm and know that these are hitchhikers not indoor pests that will colonize your home. Most of the insects will die quickly in the dryer indoor environment. Treating the tree with insecticides is not usually necessary. But if treatment becomes necessary, we could treat the tree outdoors undecorated before you move it back in.