Fall is when insects and spiders that overwinter as adults, begin looking for shelter. Often, making their way into our homes.
This activity often goes by unnoticed and the vast majority of these critters don't cause us any harm. However, there are some that we definitely don't want as roommates.
So, how do we know the difference between harmless house guests and bad tenants? And, what is the best way to evict the ones we don't want?
SDSU Extension has some answers thanks to the efforts of Amanda Bachman, SDSU Extension Pesticide Education & Urban Entomology Field Specialist, Patrick Wagner, SDSU Extension Entomology Field Specialist and Adam Varenhorst, Assistant Professor & SDSU Extension Field Crop Entomologist.
How to manage pesky invaders
The first steps to managing pesky insects and arthropods who invade our indoor space, is to learn how to identify them and how to dispose of them. In case the reader is having a difficult time visualizing what an arthropod is, Bachmann has a simple way to describe the term. "Arthropods include insects, spiders, millipedes, centipedes and everything that is crunchy on the outside."
Begin with these precautionary steps:
- Visually inspect the home for any structural entry points and fix any that are found.
- Check the weather-stripping around doors and replace any that doesn't provide a tight seal or appears to be hard/weathered.
- Check around windows to ensure there aren't any gaps or spaces around them and check to see that they close properly without any gaps.
- Don't store grain or grain-based products (including dry pet food) in open containers or containers that don't provide an airtight seal.
- Apply summer/fall insecticide perimeter sprays around the outside of the home.
Harmful pests
Although most insects and arthropods are harmless, there are some that can cause harm to humans and/or pets either by direct feeding or by infesting food or clothing items.
These include: bed bugs, fleas and lice.
Getting rid of these serious pests requires professional assistance to provide the homeowner with protocols they can follow or, in the case of bed bugs, typically, professional pest control is required.
Although mosquitoes and ticks will feed on humans indoors, we have not included them in this category because they are not capable of completing their life cycle in the home.
Some less serious include: cockroaches, flour beetles, Indian meal moths, larder beetles, carpet beetles and clothes moths. These will feed on food items or animal-based household products such as clothes, carpet and, yes, even insect collections.
These less serious indoor insect pests can be handled in the following ways: for cockroaches, Indian meal moths and flour beetles, remove the food source and store products differently. Get rid of clothes moths by using cedar. And a vacuum can quickly take care of larder and carpet beetles.
Accidental invaders
Like their group name implies, these are the insects and spiders that accidentally find their way inside and, they would much prefer to remain outdoors because accidental invaders do not feed or reproduce indoors.
Common fall invaders in South Dakota include picture wing/attic flies (Figure 2), boxelder bugs (Figure 3), multicolored Asian lady beetles and Western conifer seed bugs (Figure 4).
Most can be dealt with via mechanical means, such as a shoe, broom, vacuum or catch and release.
Now there is an exception, when it comes to the multicolored Asian lady beetle (Figure 1), a vacuum is not the best solution, as this particular species of lady beetle is capable of emitting a strong, displeasing odor that will linger in vacuums. The best course of action is to simply catch the beetle in a container with a lid and then discard outdoors.
Every fall, we get reports of millipedes in garages and basements - spaces that end up being too dry for these moisture-loving arthropods. They can't find their way out before drying out and dying. This is why they are normally observed curled up along a wall, these are best removed with a broom and dust pan.
Large spiders also fall into this category.
It seems that the larger the spider, the more dangerous people think it is. Thus, wolf spiders (Figure 5), grass spiders, and some of the bigger orb weavers get killed only because they look scary.
However, these insects do not pose a direct threat to humans and can be removed from a house using a catch and release tactic or simply by squishing them.
The presence of spiders around a home can indicate an increased amount of prey present around the home. One simple method of reducing spider populations is to ensure that insects aren't attracted to your home at night by reducing the amount of light shining through windows or reducing the time that outdoor lights are on.
Figure 1. Multicolored Asian lady beetle.
Figure 2. Picture winged fly.
Figure 3. Boxelder bug.
Figure 4. Western conifer seed bug.
Figure 5. Wolf spider.