When Insects Invade

(News article for February 1, 2020; edited)

I remember my first encounter with Asian lady beetles. I lived on the seventh floor of our college dormitory in Birmingham, Alabama, and these mystery insects started showing up in the windowsill of our common room. I wasn’t all that bothered by them, but one of my suitemates was particularly unhappy about these invaders. When I visited my parents back home in Louisiana, I found that these same insects had discovered their living room, as well.

Five years later, when I was preparing to start a job as an extension agent in North Carolina, one of my first questions for our entomology extension specialists was what to do about Asian lady beetles. What I learned is something that I have since passed on a number of times: Vacuum them up, and dump them out. If you don’t want to dump out the whole vacuum cleaner bag or have dead insects in the bag, put some pantyhose over the end or between sections of the vacuum wand to catch them before they go in the bag.

Sometimes, a person’s first thought upon seeing insects is a pesticide. Pesticides are valuable tools but not necessarily the best tool in such situations. If you spray those Asian lady beetles and they die, I assume that you’re still going to want to get them out of the house.

Vacuuming can also be useful for preventing problems with carpet beetles, for example.

While the vacuum cleaner is one valuable weapon in the fight against indoor invaders, here are some other basic principles to keep in mind when dealing with or trying to avoid them.

Exclusion should be the primary defense against indoor invaders of any kind. Make sure screens don’t have holes; keep spaces around doors closed with sweeps/thresholds and weatherstripping; use an appropriate material to fill in spaces around wires, cables, and pipes that enter the house; caulk gaps around windows, in siding, etc.; and screen gable vents.

Another facet of exclusion is keeping flour and other foods in sealable containers to avoid infestations of Indianmeal moths, drugstore beetles, and similar pantry pests.

While I’m on the topic of pantry pests, I’ll mention that putting materials (flour, pasta, etc.) suspected of containing insect eggs in the freezer for four or five days is a way to deal with products that may or may not be infested.

Sanitation is another major part of avoiding indoor pest problems. Leaving food or open drink bottles sitting around invites trouble with ants and roaches. Another type of sanitation involved in avoiding indoor pests is keeping the “gunk” out of the drains. Drain flies may appear if the sink or tub drains are lined with organic matter, in which they breed and on which larvae feed. Getting rid of this organic matter can be helpful in preventing drain fly issues.

You may be able to avoid bed bugs using sanitation-related precautions, as well. If you go on a trip and stay in a hotel, etc., set luggage on top of a luggage rack or piece of hard furniture rather than on upholstered chairs or on the floor. Check clothing and luggage when you get back. You can put clothing in the dryer for thirty minutes to kill any hitchhikers.

Moisture in or around the house sometimes contributes to indoor insect problems. For example, if plants are kept too wet, fungus gnats may be an issue. Booklice are also examples of insects that are more likely to be present when the humidity level is high.

There are times when pesticides are probably a needed component of an indoor insect management strategy. For example, if indoor ants continue to be a problem after any food or drink has been removed, baits can be used. While not all ants are equally attracted to each type of bait and it’s possible that the first bait you choose won’t be as enticing to your type of ants as another one might be, don’t think that a bait product isn’t working just because ants don’t drop dead when they contact it—for baits to be effective, insects need to live long enough to take them back to their colonies. It may take one or multiple weeks for a bait to have its full effect. Indoor baits are available for roaches, as well.

There are also pesticides, containing either a bait or a contact insecticide, for treating around the perimeters of buildings. Appropriate baits can be used to kill colonies of ants around the outside of the house before they come inside. Contact insecticides can be used to leave a residue of insecticide on a surface where ants are expected to cross. For example, if you know that ants are coming in under the door, in spite of your intact sweep and threshold, you could spray an appropriate contact insecticide in that area.

Anytime you use a pesticide, indoors or outdoors, be sure to read and follow label instructions. Let me know if you have questions.

Contact Mary Helen Ferguson.

20200129_150137cropped2jpg20200129_150001croppedjpgAsian lady beetles hanging in the author’s office as she prepared this article. (Photos by M.H. Ferguson)

11/1/2021 9:42:34 PM
Rate This Article:

Have a question or comment about the information on this page?

Innovate . Educate . Improve Lives

The LSU AgCenter and the LSU College of Agriculture