Friday, December 05, 2008
Norfolk Island Pines as Christmas trees; Sources of soldier beetles
John Arbogast
Landscape consultant John Arbogast answers your questions every Thursday. Send questions about your lawn, garden, plants, or insects to:
Dear John
5102 Greenfield St. SW
Roanoke, Va. 24018
Or send an e-mail. Answers will be given only in this column. Please don't send pictures or samples.
Recent columns
Q: What is your opinion about using Norfolk Island Pines as Christmas trees, especially for small places like apartments?
A: I think that using a Norfolk Island Pine for an indoor Christmas tree is a great way to be "environmental." If certain care practices are followed, a Norfolk Island Pine can make a great indoor green plant after the holidays. That sure does beat the sad picture of a big Christmas tree put out with the trash after the holidays, without knowing if it will be shredded into mulch or not.
Norfolk Island Pines need bright sunshine indoors, so you should carefully choose their location as a Christmas tree. Also, lights and Christmas decorations placed on a Norfolk Island Pine should be lightweight in order to avoid branch breakage. Water the plant as you would any indoor plant. And make sure that the container you plant the tree in has drainage holes for the excess water to run out.
Q: We get soldier beetles in our house in Australia. They are a foliage beetle, and belong outside. When it's windy and you open a door, in they come. If you get the exterminator to spray your home for cockroaches, it is very effective in taking care of the soldier beetle.
A: Thanks for your note from Australia. Wow! As a veteran residential landscape and vegetable gardener in Virginia who grew up in a small town in the mountains of West Virginia, I continue to be amazed that the horticulture question-and-answer column that I wrote for more than 24 years for newspapers in Virginia and now for more than six years on roanoke.com reaches the U.S. all around the world.
I don't know much about residential pesticide use in Australia, but here in Virginia and in the U.S. in general, there is great concern -- and there are many legal controls -- that surround pesticide use and storage, mostly dealing with human safety. We often use physical controls, rather than take risks with chemicals, especially in places where humans and/or pets might be exposed.
In the case of soldier beetles, American insect professionals realize that, in its young (larvae) stage and adult stage, a soldier beetle will not infest a house or bite humans. Professionals also realize that it is probably not useful or even possible to achieve much chemical control of soldier beetles, since they may come from almost any direction -- and thus makes the decision of where to spray nearly impossible. Here, insect professional espouse the philosophy of controlling insects at their source, rather that spraying just because we see them. Thus, the recommendation to sweep soldier beetles up or out of the house is the rule.
We also try to determine what is attracting the specific insects in order to eliminate the attractant, if possible. Your note mentioned that soldier beetles in Australia are a foliage beetle, which they are here in Virginia, as well. Can you eliminate -- or, at least, reduce -- the soldier beetles' outdoor home so that they're not close enough to an open door to blow in when it gets windy?
Dr. William Robinson, now a retired extension entomologist at Virginia Tech, wrote that adult soldier beetles here in Virginia, which are yellow and black, are found in large numbers on the flowers of goldenrod, milkweed and other plants in the late summer and fall. They feed on the pollen and nectar of the plants, mate and lay eggs. The eggs soon hatch, and the half-inch long, velvety black larvae have well-developed legs and prominent mouth parts that they use to feed on other insects found in the grass surrounding houses. Soldier beetles prey on caterpillars and other soft-bodied insects found on the ground. The larvae of some soldier beetle species prey on grasshopper eggs.
I hope this discussion helps you think about outdoor attractants for soldier beetles near your home -- and sources that you can eliminate or modify before these insects blow in your open door. The idea of indoor attractants should help you think about lures and food for cockroaches that you can discuss with your exterminator.
