Bugs from Christmas tree

We purchased a Christmas tree less than two weeks ago. Yesterday we noticed small winged black bugs. We are finding them on the ceiling. The majority of them are in the living room where we have the Christmas tree, but we are finding them throughout the house. I don't know how else to phrase this, but when you get them with a napkin a lot of brownish/blood comes out. We have been getting them with the vacuum cleaner. I'm not sure if we need to dispose of the tree or if we can get this under control. They resemble a gnat. The tree is a fresh cut tree, so no soil is involved. We have noticed the numbers getting smaller. I just want to make sure they are not reproducing and that this is not going to be an ongoing problem. Lou and Linda

Without seeing the insects that concern you, I will guess that they are aphids. There are many types of aphids, some that feed on coniferous trees, such as your Christmas tree. They may have been on the tree when you brought it indoors and became active once they warmed. However, there are other possibilities other than the Christmas tree. The information that makes me believe that aphids are the problem is the description of the brownish fluid ("blood") you described from smashing them while collecting them with a napkin. Aphids are soft bodied and smash easily, and their internal fluids may have the brownish color you described.

Aphids have winged and wingless forms—those on the ceiling are probably the winged form. You should be able to find the wingless form on the host plant, or plants upon which they are feeding. This may be the Christmas tree, but it may also be other houseplants. It would be a good idea to carefully check the Christmas tree and then your houseplants for the wingless forms to determine the source of the infestation. If the aphids are a conifer aphid, they are probably not a cause of concern for your houseplants. However, if you can collect some (unsmashed) and take them to your local Cooperative Extension Service office, the Extension Agent there can help you determine if these are likely to harm houseplants and can also help you determine a safe course of action for your circumstances.

If aphids are not found on your Christmas tree, then inspect your houseplants carefully. If the houseplants are the source, then treatment will need to be directed at them.

If houseplants are infested, there are several safe treatments for indoor use. One is to carry smaller plants to the bathtub and give them a shower with a hand-held shower. Larger plants may be taken outside on a warm day and washed down. Insecticidal soap may also be used—just be careful to protect your carpet, upholstery, and draperies from the spray.

If the problem is the Christmas tree, it may be possible to just tolerate the problem for a little longer, then remove the tree. Or, you may remove the decorations from the tree, take it outside, and wash it down with a strong stream of water. This could also be done to trees before they are brought indoors and decorated. If you want to use insecticidal soap on the tree indoors, remove the decorations and protect the fabrics mentioned above.

Send gardening questions to Southwest Yard and Garden, Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu or at https://www.facebook.com/DesertBloomsNM/. Please include your county Extension Agent (aces.nmsu.edu/county) and your county of residence with your question!

For more gardening information, visit the NMSU Extension Horticulture page: desertblooms@nmsu.edu.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, office: 505-865-7340, ext. 113.