Photograph by Cannabis Horticultural Association

Photograph by Cannabis Horticultural Association

 Larva of Harmonia sp., a lady beetle. Photograph by Lee Ruth, BugGuide.net.

Larva of Harmonia sp., a lady beetle. Photograph by Lee Ruth, BugGuide.net.

Lady beetles "Ladybugs"

Lady beetles are easily recognized by their shiny, convex, half-dome shape and short, clubbed antennae. Most lady beetles, including this species, are predaceous as both larvae and adults. Young lady beetle larvae usually pierce and suck the contents from their prey. Older larvae and adults chew and consume their entire prey. Larvae are active, elongate, have long legs, and resemble tiny alligators. Many lady beetles look alike and accurate identification requires a specialist.(UC IPM)

There are hundreds of different species and most are predators both as adults and larvae. Some species specialize on aphids or other groups; others have a broader diet. Ladybugs are one of the most widely used beneficial insects. Excellent aphid predators, they will also feed on thrips, whiteflies, mites and many other soft-bodied insects and eggs that reside above the soil. A cost effective alternative to other treatments, the easy-to-release ladybug has a great reputation as a generalist predator. When temperatures exceed 90° Green Lacewing are a great alternative general predator.

In general, ladybugs are not effective controls for spider mites. They will provide some management when spider mite populations are low. Ladybugs are a much more effective as a predatory insect for aphids. When ladybugs are released they generally like a source of water, otherwise they might fly away.

 

Target Pest: Alfalfa Weevil, Aphids, Armyworm, Caterpillar Eggs, Greenhouse Whitefly, Leafhopper, Mealybug, Thrips, Two-Spotted Spider Mite

    Release Rates and Instructions: Release immediately. 60 - 88°F

     Newly hatched lady beetle larvae. Photograph by Jim Kalisch, University of Nebraska, Lincoln.

    Newly hatched lady beetle larvae. Photograph by Jim Kalisch, University of Nebraska, Lincoln.

    • When releasing outdoors make sure that there is shade for the ladybugs.
    • Try to release in the evening so that they have some time to adapt to your location.
    • Give your plants a light misting of water before the release.
    • The ladybugs may become dehydrated during travel.
    • The moisture will also help to attract and retain the ladybugs.

    4,500 for up to 2,500 square feet.
    9,000 for up to 5,000 square feet.
    18,000 for up to 10,000 square feet.
    35,000 for up to 1/2 acre.
    70,000 for up to 1 acre

    Each adult consumes about 5,000 aphids. Approximately 8 to 10 days of release, each female ladybug lays 10-50 eggs daily on the underside of leaves. In 2-5 days the larvae emerge as dark alligator-like flightless creatures with orange spots. The larvae eat 50-60 aphids per day.

    Lifespan: Typically, ladybirds have several generations each year, and reproduction is slowed or halted by cooler winter weather, when adults may hibernate.

    Strategic Considerations:  Avoid spraying with pesticides, both before and after release. Soap sprays, such as Safers, are an exception - you can use them right up to the arrival of the ladybugs, and indeed, ladybugs hard outer shell seems to protect them from soapy sprays even afterwards. Botanical pesticides such as pyrethrin are ok to use if you wait a week before releasing ladybugs.)

    Selected References

    New record of predatory ladybird beetle (Coleoptera, Coccinellidae) feeding on extrafloral nectaries Lúcia M. Almeida1, Geovan H. Corrêa, José A. Giorgi2 & Paschoal C. Grossi

    University of Florida Department of Entomology and Nematology

    UC IPM Lady Beetles

    UC IPM Identification: Natural Enemies Gallery. Convergent lady beetle.

    Flint, M.L. and S.H. Dreistadt. 2005. Interactions among convergent lady beetle (Hippodamia convergens) releases, aphid populations and rose cultivar. (PDF ) Biological Control 34 (2005): 38-46.
    Flint, M.L.; S.H. Dreistadt, J. Rentner, M.P. Parrella. 1995. Lady beetle release controls aphids on potted plants. California Agriculture 49(2): 5-8.