Park Service does not release Asian Lady Beetles
The Asian lady beetle is a predatory lady beetle native to eastern Asia. Lady beetles are often used as a biological control agent targeting soft-bodied insects such as aphids and scales. An adult lady beetle is capable of eating 90-270 aphids per day. Lady beetles are now present across much of North America, with reports as far west as Oregon. In their native Asian environment, lady beetles stay in cracks and crevices of cliffs in the winter, but in many areas of the United States, these beetles become a nuisance when they gather in buildings (because of the lack of warm cliffs), often emitting a noxious odor and yellowish fluid when alarmed. The population boom has probably been caused by the massive abundance of prey and a lack of natural enemies. The Asian lady beetle is also known as the Halloween lady beetle and the Japanese lady beetle.
Myths and Misconceptions about the Asian Lady Beetle
The National Park Service has never released Asian lady beetles in or near Great Smoky Mountains National Park. The Park Service has recently released tiny black beetles that prey on hemlock woolly adelgids (which kill hemlock trees), but they are tiny, the size of a pinhead, and do not congregate in homes during winter.
- Asian lady beetles do not reproduce in structures. Mating occurs after the beetles leave their hibernation site.
- The beetles do not carry diseases that affect humans.
- The beetles do not eat wood or building materials.
Why was the Asian Lady Beetle Brought to the United States?
From the 1960s to 1990s, federal, state, and private entomologists released the insect in a number of places to control agricultural pests, especially of pecans and apples. Large numbers were released in Louisiana and Mississippi. In addition, accidental entries of Asian lady beetles have occurred via imported nursery items at ports in Louisiana, Delaware, and South Carolina. Asian lady beetles are also sold by gardening suppliers.