The larva is a rather fearsome looking beast. Adults can live as long as 2 to 3 years under optimal conditions. In most species it is a fierce predator. Many people ask how to control lady beetles in the home. One of these lady beetles is the mexican bean beetle, The larvae hatch in about a week and start to eat aphids or other appropriate food. Dwellings near woods or fields are especially prone to infestation, although those in other locations can be infested as well.
Asian bean beetle. Make sure your home is insectproof by keeping windows and doors fitting tightly, caulking cracks and crevices leading from the outside to the inside and screening all vents especially in the attic. Once inside they crawl about on windows, walls, attics, etc. Can be a nuisance however, when they fly to buildings in search of overwintering sites and end up indoors. They should understand how beneficial they are and how they fit into the natural scheme of nature. In about a month the larvae will pupate; this stage lasts about a week.
There really is no justification for spraying a chemical insecticide to control these beneficial insects. Which is a serious pest of bean crops.