A number of arthropods live on Christmas trees while others may use them for winter shelter. Most are inactive or sluggish at outdoor temperatures but become active when their tree is brought indoors.
The awakening can cause some alarm but usually poses only a temporary nuisance. It is best to deal with these accidental invaders by swatting, spraying directly with insecticidal soap, or wiping up with a soapy rag. Do not spray ready-to-use insecticides indiscriminately or set off “bug bombs” to deal with the problem.
White Pine Aphid
Colonies of white pine aphids are common on shoots and branches of eastern white pine and Scots pine. Wingless aphids crawl while winged adults may fly. These soft-bodied insects are sap feeders. They will not become established household pests.
Pine Needle Scale
Pine needle scales are sap-feeding insects that prefer Mugo and Scots pine but can live on other pines and spruce. Infestations of the narrow, white waxy scale coverings are very apparent on needles of infested trees. The narrow waxy white coverings protect a batch of eggs that normally hatch in spring. The tiny red crawlers may become active on trees that are indoors for a long time. They pose no threat to houseplants and can be wiped up with a soapy cloth.
Even though praying mantid eggs can survive a long, hard winter, they hatch relatively soon after being brought indoors. Scores of tiny mantids will crawl around looking for prey, usually consuming any siblings they encounter. Tap the small mantids into a container of soapy water or trap them on sticky tape exposed on branches where they are active.
Many spiders spend the winter as eggs in masses protected by a covering of silk. Sufficient exposure to warm temperatures can stimulate egg hatch with tiny roaming spiders exploring their new world. The same remedies for newly hatched mantids will help to reduce spider numbers relatively quickly.
Some species pass the winter as inactive adults on tree trunks and other similar sites. Often they are larger than the other common tree dwellers but pose no problem other than some temporary anxiety.
Identification and Management Assistance
You can get help with insect identification and management recommendations at your local Cooperative Extension Service office. To locate the office for your county, go to http://www2.ca.uky.edu/county/
By Lee Townsend, Extension Entomologist