Asian Lady Beetles
Lady beetles on occasion will bite, but do not leave any permanent mark or cause any kind of allergic reaction. Lady beetles cannot breed or reproduce indoors like fleas or cockroaches. Nonetheless, some people will not tolerate insects of any kind in their homes. Given these varying levels of tolerance, we offer the following management options.
Prevention and control
Because the beetles seek out over-wintering sites in the fall, exterior cracks and openings should be sealed as a long-term, preventive measure.
- Adjust or install tight-fitting door sweeps or thresholds at the bottom of all exterior entry doors. Gaps of 1/8″ or less will permit entry of lady beetles and other insects. Garage door bottoms should be fitted with a bottom seal constructed of rubber (vinyl seals poorly in cold weather). Gaps under sliding glass doors may be sealed with foam weather-stripping.
- Seal utility openings where pipes and wires enter the foundation and siding, e.g., around outdoor faucets, receptacles, gas meters, clothes dryer vents, and telephone/cable TV wires. Holes can be plugged with caulk, cement, urethane foam, steel wool, or copper mesh.
- Caulk cracks around windows, doors, siding, and facia boards. Use a good quality silicone or siliconized acrylic latex caulk. Although somewhat less flexible than pure silicone, siliconized latex-type caulks clean up with water and are paintable. Caulks that dry clear are easier to use than pigmented ones because they cover mistakes.
- Repair damaged window screens and install insect screening behind attic vents.
Interior Treatment. The easiest way to remove ladybugs, once they are indoors, is with a vacuum cleaner. A broom can also be used to remove beetles indoors, but is more likely to cause staining. (The orange-colored fluid that the beetles secrete when picked up or disturbed is harmless, but will stain walls and other surfaces.)
Exterior Treatment. An 80/20 mix of water and liquid dish soap sprayed onto the bugs works well.
Indoor Treatment. Insecticide foggers or sprays are generally NOT recommended for eliminating lady beetles indoors. Beetles need to be sprayed directly, or have to crawl over treated surfaces, in order for the insecticide to be effective. Such applications create pesticide residues on walls, countertops, and other exposed surfaces. A vacuum cleaner is more sanitary and effective.
Exterior Treatment. While sealing openings is the more permanent way to deny beetles entry, comprehensive pest proofing is time-consuming and sometimes impractical. There are often too many cracks under and around eaves, siding, vents, etc., where beetles can potentially enter a home. On multi-story buildings, sealing becomes still more difficult.
If a household or business continues to be infested by lady beetles, owners can purchase ready-to-use products or enlist the services of a professional pest control firm. Many companies offer insecticide treatment of the building exterior, which helps to prevent pest entry. Fast-acting, residual formulations of insecticides can be applied around likely points of pest entry. The key is to initiate such treatments in late September or early October, before the beetles enter buildings to over-winter. Once the beetles are indoors (i.e., winter/early-spring), such treatments would be ineffective.
Brand Names- synthetic pyrethroids
- Bifenthrin: K-Gro- Home Pest Control, Ortho- Home Defense Indoor and Outdoor Insect Killer, Ortho-Klor Termite & Carpenter Ant Killer, Ortho- Rose & Flower Insect Killer, Talstar
- Cyfluthrin: Raid- Max Roach & Ant Killer, Bayer- Advanced Garden Multi-Insect Killer, Tempo, Baythroid, Laser
- Cypermethrin: Viktor- Home & Patio Insect Control, Demon, Cynoff, Sniper, Ammo, Mustang
- Deltamethrin: Viktor- Ant Killer, InterCept- Home & Garden Insect Control Granules, Green Light-Roach, Ant & Spider Control, Delta-Eight, Deltagard, Enforcer
- Lambda-cyhalothrin: Spectracide- Triazide Soil & Turf Insect Killer, Scimitar, Battle
- Tralomethrin: K-Gro- Home Insect Killer, Spectracide- Bug Stop Indoor and Outdoor Home Insect Control, Spectracide- Wasp & Hornet Killer, Saga, Scout X-tra
BE SURE TO FOLLOW THE MANUFACTURERS DIRECTIONS ACCURATELY WHEN USING ANY PESTICIDE.