Hippodamia convergens are ladybugs that can be identified with white, dash marks above the wings. This type is popular for use as natural pest controls in greenhouses and gardens.
These helpful ladybugs can be purchased by gardeners to reduce problematic scale, mites, thrips and aphids. Companies advertise the best time to release the ladybugs is early evening, so they can get settled in and locate food, especially water, since they most likely traveled a distance to get to your garden. One larvae can eat 400 medium-size aphids as it transforms to its pupal stage. An adult ladybug can eat over 5,000 aphids during its year-long life.
I've never tried to order ladybugs before. Sellers say that you can store them in the refrigerator for 2-3 months. Why would you want to do this? Because repeated, regular releases of small amounts of ladybugs can be more effective than one, big release.
Suggested release rates for ladybugs vary widely, according to Nature's Control located in Medford, Oregon. They report seeing recommendations varying from 1 gallon (72,000) for 10 acres, to up to 3 gallons per acre. Their philosophy is that you can't use too many ladybugs. They recommend 1,500 ladybugs as usually enough for one application for home use in a small greenhouse or garden; for larger areas, a quart (18,000) or gallon (72,000) of ladybugs is suggested.
In our garden we have also seen the more unwanted, Harmonia axyridis, also known as harlequin ladybugs. They also are often the culprits in home invasions. Harlequin species were introduced to North America from Asia in the early 20th century for aphid control and have taken over many of the native species, wearing out their welcome in our gardens, especially when they decide to infest and hibernate in your house!
Children love ladybugs. Take them on a garden tour and give them a hands-on fun lesson about ladybugs and their life cycle. It takes 2-3 weeks for ladybug larvae to develop into adult ladybugs. There are many informative websites that offer detailed information and materials specifically for teaching children about ladybug lifecycles.
Related Links: Dave's Garden BugFiles
Photo credits: Thumbnail art: Wikipedia GNU Free Documentation License. A diagram of the anatomy of the Coccinellidae (ladybug), source: Persian Poet Gal. All other photographs Copyright ©2012 Wind. All rights reserved.