Many gardeners like to save some plants from Jack Frost by bringing some plants in from the flower garden or moved some of those container gardens indoors. Others took cuttings of their favorite plants, get them rooted and continue to enjoy them on their windowsills over the winter. Whatever you like to do, it probably means that your limited indoor gardening spaces will become more heavily populated with plants than they were during the summer months. As plants are more closely packed together, the greater the likelihood that pest problems may spread from one plant to another and also a plant that had a minor pest problem outdoors, may suffer a more significant infestation inside the home.
Fall is here, but many insects are still active, especially on unseasonably warm days. During the fall, insects that spend the winter as adults begin looking for shelter. These are the critters most commonly finding their way inside, and generating questions about their identity and motives.
Wasps receive attention no matter the time of year, but they are especially noticeable in late summer and early fall. Wasps such as yellow jackets and paper wasps have annual nests, so the majority of the individuals that are active now will not survive the winter. Only the newly produced queens will find a sheltered location to overwinter and begin a new colony in the spring.
Sod webworm moths are emerging throughout South Dakota. Although these pests are common during the fall, the number of moth sightings and population densities in the Western half of the state are higher than normal. The particular species being found is the vagabond sod webworm. Unlike several other webworm species found in the United States, vagabond sod webworms rarely cause much damage and the adult moths are no more than just a short-term nuisance.
Praying mantises are one of the most distinctive large insects that can be found in South Dakota. Their striking appearance, size and perceived rarity contributes to the frequent calls and emails that we receive regarding sightings and captures of these insects.
Japanese beetles (Popillia japonica) are present in a few areas of South Dakota. So far, they have a foothold in the southeast corner of the state and appear periodically in the Brookings area. Sporadic populations can show up in other parts of the state, and are thought to be brought in on infested nursery stock or otherwise accidentally moved by people.
Cicada killer wasps (Sphecius speciosus) are active now and attracting a lot of attention due to their large size and fearsome appearance. The female cicada killer wasps dig tunnels in areas of bare, sandy soil. These conditions often exist near garages, patios, sidewalks, retaining walls, and in playgrounds.
The latest insects to find their way inside South Dakota homes are the root weevils. Root weevil adults feed on many plants in the landscape but appear to prefer lilac leaves and yews in early summer. Their larvae feed on the roots of a variety of plants in the landscape. The mature larvae overwinter, pupate in the spring, and new adults emerge around June.
Rose sawflies are also called roseslugs and are in the order Hymenoptera. Despite their common name, they are neither flies nor slugs. The larvae resemble caterpillars. They are small and light green with a tan head capsule. The larvae feed on the surface of the leaves, and do not chew through the whole leaf. This results in ‘windowpane’ injury or skeletonization of the leaves.
The wet conditions in the Southeast portion of the state this spring resulted in a large number of earwigs showing up in homes and gardens. Earwigs are very distinctive and are often feared by onlookers due to the pincer or forceps appendages present at the end of their body, but they are not harmful to humans. The pincers (called cerci) are used for defense, but earwigs do not seek out humans to attack.