Several years back, in the autumn, these invaders started showing up in my home. At first glance, one would think they're the old-time, friendly ladybugs from nursery rhymes of childhood; and they are a close relative. They aren't quite as pleasant to live with, though. Here's what I gleaned about these pesky critters:
How Did These Exotic Lady Beetles Get Here?
The multicolored Asian lady beetle made its way into the United States through a number of accidental and planned releases. There are several reports that this species was accidentally brought on ships to various ports, notably New Orleans and Seattle. This lady beetle was also intentionally imported from Russia, Japan, Korea, and elsewhere in the Orient and released in the United States as part of a Federal effort to naturally control insect pests in trees. The rationale was that native species of lady beetles are not particularly effective in controlling tree-feeding aphids and scale insects. The Federal releases were made in California as early as 1916 and again in the mid-1960s, but the multicolored Asian lady beetle apparently failed to establish.
During the late 1970s through the early 1980s, tens of thousands of multicolored Asian lady beetles were intentionally released by the U. S. Department of Agriculture's Agricultural Research Service (USDA-ARS) in an effort to control insect pests that injure trees. The USDA-ARS coordinated the lady beetle releases in many southern and eastern states The USDA-ARS release program was eventually discontinued because failed recapture efforts suggested that the multicolored Asian lady beetle was not surviving in the United States.
Hence, there is some controversy regarding the origins of this nonnative species. Nonetheless, the multicolored Asian lady beetle is now well established in the United States, where it currently thrives in many parts of the Midwest, East, South, and Northwest. This nonnative species appears to be displacing some of our native lady beetles in Ohio.
Good Ladies, …
The multicolored Asian lady beetle is an important predator that consumes aphids and scale insects on trees, shrubs, and agricultural crops. During the spring and summer, the immature and adult lady beetles consume large numbers of plant-feeding pests, thereby reducing the need for pesticides. The multicolored Asian lady beetle has significantly benefited the pecan industry by nearly eliminating injurious pecan aphids. It also has impacted pests that injure other commodities, such as fruit orchards, Christmas trees, ornamentals, small grains, and many agricultural crops.
… With Some Bad Habits!!!
In spite of their important role in nature, multicolored Asian lady beetles can be seasonal pests in and around homes, particularly from late autumn until early spring.
Nuisances. Homeowners often express concern and aggravation with these nuisance pests. During late autumn, homeowners complain that multicolored Asian lady beetles cluster on the sides of houses; "crunch" under foot; get into food and drinks; alight on hands, arms, and other parts of the body; and sometimes enter the ears and mouth. The lady beetles can be so numerous that they appear to be "raining" outdoors or swarming like bees. A variety of other problems are associated with these lady beetles, as detailed below.
Home Invasion. Unlike our native species of lady beetles, the multicolored Asian lady beetle seeks protected hibernation (overwintering) sites in and around buildings. They may occur in any type of structure. Because these exotic lady beetles readily occur on trees, homes in forested areas are often infested. Multicolored Asian lady beetles often are pests in log homes, because they can slip through the cracks and crevices between the logs.
Multicolored Asian lady beetles seek protected sites where they can hibernate. Some may overwinter underneath siding, roof shingles, landscaping timbers, or leaf litter. Others readily slip through cracks and crevices and come indoors, where they make themselves at home. They may cluster together in corners of porches, attics, soffits, wall voids, door or window frames, or dark, undisturbed areas within buildings. The beetles can form large, hidden aggregations in secluded dark locations inside homes, commonly in attics and basements. They periodically invade living spaces, apparently in response to the warm interior temperatures. On warm sunny days during the winter, they tend to move about and fly within living spaces. They readily fly to windows. During the spring, these lady beetles are particularly noticeable in houses when they leave their hibernation sites and attempt to make their way outdoors.
Stains and Odor. When lady beetles are disturbed, they defend themselves by exuding a yellow-orange body fluid, which is their blood. This defense mechanism is termed reflex bleeding. The blood has a foul odor and can permanently stain walls, drapes, carpeting, etc. Thus, do not crush or swat lady beetles so as to minimize their defensive behavior.
"Bites." Although an uncommon occurrence, multicolored Asian lady beetles have been reported to nibble, nip, or "bite" humans. These lady beetles are not aggressive toward humans, and they simply may be examining an unfamiliar substrate or they may be seeking moisture. Their occasional nibbling is not reported to break the skin or draw human blood.
Allergic Reactions. Some individuals report an allergenic response to lady beetles. Although published reports are uncommon, multicolored Asian lady beetles apparently can cause inhalant allergies. These allergies clear up once the lady beetles are removed.
Some people are sensitive or allergic to the fluid that lady beetles secrete, which can cause contact dermatitis and a stinging sensation. However, lady beetles cannot sting, because they do not possess a stinger.
I found all this information HERE. (I like to give credit where credit is due.
Around here, these varmints live in the soybean fields; so as soon as the farmers start harvesting soybeans, the bugs invade my house. Couldn't someone make a horror movie out of this? "The Curse of the Ladybugs"?