Submitted to the Contra Costa Times on October 18, 2004

Q. Where can I get vedalia beetles?

A. Rodolia cardinalis, Vedalia beetles, are a kind of ladybeetle, and are one of the first great success stories for Biocontrol in California. These beetles prey exclusively on cottony cushion scale. They are considered to be well established in California and are not commercially available at this time. 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.

Adult vedalia beetles are small, measuring 2-4 mm (<3/16 inch) long, and are red and black with a covering of fine hairs which often gives them a grayish appearance. The larvae are reddish in color. Oblong, red eggs are laid singly or in groups on or near cottony cushion scales. R. cardinalis has 8 or more generations per year.

Both adults and larvae feed exclusively the cottony cushion scale on a variety of plants including rose, acacia, magnolia, olive, and citrus. Adults and mature larvae feed on all stages of the scale while young larvae feed only on eggs. The vedalia beetle is extremely sensitive to some pesticides and care should be used when applying pesticides in areas where the beetle is relied upon for control of the cottony cushion scale.

More information and photos of vedalia beetle can be found in UC ANR publication 8051 (PDF* 438K)