Asian lady beetles were deliberately imported into the United States where large populations were released into commercial crops as a biological pest control agent. These non-native insects have been used to control damaging aphid populations within US crops numerous times over the course of the 20th century. Although Asian lady beetles proved effective as a biological control agent, they eventually spread beyond agricultural areas and into urban and suburban locations during the early 1990s. Unfortunately, this species’ potential as a nuisance pest was realized once these insects began to swarm into people’s homes during the fall season in an effort to secure warm shelter before the arrival of winter. In addition to their nuisance swarms, Asian lady beetles gravitate into areas of a home that are hard-to-access, such as wall voids and below baseboards. This can make indoor infestations difficult to eradicate. Today, Asian lady beetles have spread to many US states, but they first appeared outside of agricultural areas in 1988 when large populations were found in rural and suburban fields in Louisiana.

While non-native Asian lady beetles have been released into US crops many times, the officials in charge of these dispersals were vigilant about containing these insects to prevent them from establishing an invasive population outside of agricultural centers. Nobody knows for sure how these insect pests established a thriving population within Louisiana where they frequently invade homes all over the state, but some experts believe they arrived within shipping containers. The ladybug pests became particularly problematic during the fall of 2016 when numerous homes in Baton Rouge became inundated with these pests, and many residents claimed to have sustained bites. It is not uncommon for residents to sustain bites from Asian lady beetles, especially during urban and suburban swarming events. This is why it is wise to remain indoors when Asian lady beetles congregate onto the exterior walls of neighborhood homes. Their bites are not considered medically significant, but they are certainly noticeable. In addition to their bites, Asian lady beetles emit an odor that most people describe as unpleasant. This odor becomes apparent after specimens are crushed or when they become disturbed, and in some cases, infested homes become saturated with their odor. These beetles enter homes through foundation cracks, spaces below doorways, through compromised window screens and many other access points. Making sure that homes are well sealed during the fall will help to keep these pests from establishing stubborn indoor infestations.

Have you ever seen Asian lady beetles congregating on the exterior walls of a home?