Do you sometimes have spiders or other creepy crawlers in your house? Could any of these house pests be the result of your landscape? The answer to these two questions is yes.
How many of you use bark mulch in planting beds near or adjacent to your house? While the use of mulches has all kinds of benefits, it could also be supplying a steady stream of creepy crawlers into your house. Some possible culprits are sowbugs (also known as pillbugs or roly-polies), springtails, field crickets, earwigs and spiders. Mulches provide ideal habitat for these pests through conditions of higher relative humidity and safe places to hide.
Another source of invading household insects could be because of the plants you have in your garden. These insects become nuisance pests, especially when they invade during the onset of winter conditions. These landscape sourced house invaders include boxelder bugs that breed on boxelder seeds, goldenrain tree bugs that feed on the seeds of the goldenrain tree, elm leaf beetles that feed on elm leaves, western conifer-seed bugs that breed on the cones of pines, and cluster flies that breed as parasites on earthworms.
The pest that can be quite spectacular in their sheer numbers is the army cutworm moth, Euxoa auxiliaris. Many call these "miller moths" although I find this somewhat redundant since millers and moths are words often used interchangeably. This moth makes annual migrations in late spring. Their numbers can literally exceed hundreds of thousand moths all at once. And their attraction to light could force homeowners to draw all their blinds and even forego lighting some rooms at night.
While living in West Texas I often experienced these migrations out of New Mexico. These moths were attracted to my flowering yaupon bushes by my entryway and consequently many found their way into my house. Their numbers could be so great that cars traveling on roads in open rangeland areas would have their windshield visibility obliterated with yucky dead moth bodies and we would have to stop frequently to clear off the offending beasties.
Flowering plants such as fruit trees, lilac, dandelions, spirea and cotoneaster attract army cutworm moths searching for nectar. Also, houses surrounded by large amounts of plants can provide dark areas for shelter during daylight inactivity periods.
So when planning your landscape and plant choices, think not only about attracting butterflies, bees, birds and other desirable visitors; consider also the nuisance pests you might inadvertently attract.
Jim Leser retired to Cedaredge in 2007 after a career with Texas A&M University Extension in entomology. He is a member of the Cedaredge Tree Board and a Colorado Master Gardener.