Asian Lady Beetle may make a Halloween house call you won’t appreciate
Around Halloween, some uninvited guests may make a surprise appearance at your home and they aren’t the two-legged variety seeking trick or treats. The Multicolored Asian Lady Beetle(Harmonia Axyridis) makes its home in the Ozarks and most of the U.S., and now is its time to reproduce and seek out a place to hibernate through the winter months.
The colorful lady beetle has shiny yellow or orange or red wing covers and a distinctive “M” marking behind the head. Their colors may vary from red, and orange to a dull cream. However, unlike the native beetles, this ladybug can be quite aggressive.
A native of Asia, the “beneficial” ladybug was imported in the early 1900’s to help naturally control pest populations that were damaging such crops as alfalfa, pecan and citrus trees.
“Like other lady beetles, this one eats aphids and other soft-bodied insects and is a beneficial insect when outdoors,” says Kelly McGowan, horticulture educator with University of Missouri Extension in Greene County.
Masses of Asian ladybugs have been known to swarm and even bite when seeking shelter for the winter months. In this regard, they have been an unwelcome guest for homeowners that don’t find them to be good luck at all, but rather a nuisance.
Worse yet, when disturbed, if stress, the Asian variety will release a yellow, smelly substance from their joints. this is known as “reflex bleeding”. It is a defensive mechanism for the insect to defend itself from predators. Worst of all, they also stink when stepped on or crushed, a fact that is highly bothersome to vintners because the smell can ruin a grape harvest.
The Halloween lady beetle congregates in large groups on sunny sides of light-colored rocks or structures where it seeks protected crevices – or enters a building through cracks, vents or other openings — to spend the winter.
“The best way to avoid invasion by the Halloween lady beetle is to tighten up your house. Caulk or seal cracks, cover attic and exhaust vents with insect screening, fix holes in window screens (making sure they fit snugly), and put sweeps and thresholds on exterior doors,” says McGowan.
The Asian Lady Beetle is much like the native species found throughout the United States. They are small, hemispherical in shape, and can be found with and without spots.
The multi-colored Asian Lady Beetle goes through four stages in its life cycle. Female adult lady beetles lay eggs on plants near colonies of aphids, mites and scale insects. Yellow eggs are laid in clusters of varying numbers. In 3-7 days, the larva hatch and begin searching for food. The larva will molt (or shed its outer layer of skin) about four times as it grows. Sometimes after the last molt, the larva will attach itself to the plant, becoming immobile as it is now in the pupa. Depending on the environmental factors, the new lady beetle will emerge from the case, looking wet, shiny and golden in color. The ladybug is very vulnerable during this time, as it waits for the exoskeleton to harden and dry revealing its true colors and markings.
Research e ntomologists have been working diligently on methods to prevent ladybugs from entering the home and on ways to safely and effectively capture them once inside. Fortunately, ladybugs are not structure damaging insects. They will not eat home materials and will not lay eggs inside the home.
If the Halloween lady beetle does make it inside, McGowan recommends gently sweeping them up and then relocating them outside.
A handy collection sack can be made by placing a knee-high nylon stocking in the vacuum hose, folding over the top of the stocking and securely fastening it to the outside of the hose.
“When you turn off the vacuum, remove the bag quickly so the captured beetles don’t escape. They can be released outdoors in leaf litter or other sheltered places,” said McGowan.
For more information on the Asian (Halloween) lady beetle contact your local MU Extension Center and request a copy of guidesheet G7369, “Multicolored Asian Lady Beetle,” or G7368, “Household-Invading Beetles.” These publications are also available online at http://extension.missouri.edu.