Have ever wonder what is eating my leaves by cutting circular holes along the leaf edges of the rose bush leaves, the citrus leaves and countless other leaves. It could be a Leafcutting Bee and you are helping a Momma Bee make her nest.

According to the University of Florida EDIS publication on Leafcutting Bees http://edis.ifas.ufl.edu/in619 They construct cigar-like nests that contain several cells. Each cell contains a ball or loaf of stored pollen and a single egg. Therefore, each cell will produce a single bee. Leafcutting bees construct these nests in soil, in holes (usually made by other insects) in wood, and in plant stems. A diversity of cavities, such as shells of dead snails, holes in concrete walls (like those produced for hurricane shutters) and other holes in man-made objects are used as nesting sites.

Before you get out the bug spray, think! The leafcutting bee is an important pollinator of many wildflowers, fruits and vegetables, trees and shrubs.

Leafcutting bees can be considered a pest because of leaf cutting on ornamental plants. Although the cutting can destroy the aesthetics, it rarely harms the plant. Since leafcutting bees do not feed on the leaves they cut, insecticides are usually ineffective for preventing leaf cutting.

Biological Control. Their a number of parasitoids that search out and attack the nests include flies, wasps (Chrysididae, Mutillidae) and beetles (Rhipiphoridae, Meloidae and Cleridae). The Coelioxys, a genus within the leafcutting bee family, are cleptoparasites (they lay their eggs in the nests of other leafcutter bees and the young “steal” all of the stored pollen). Ants, (such as Crematogaster spp. ) have been known to attack leafcutter bee nests.

Placing physical barriers such as cheesecloth on susceptible plants is a successful solution to preventing damage. These barriers should be used when leafcutting bees are most active (when you begin to observe leaf cutting).

Management. Eliminating nesting sites can reduce the number of leafcutting bees in your area. Small diameter holes (size of a nickel or smaller) in soft, rotting wood are an ideal nesting site for these bees. Holes that are plugged or stuffed with green or brown leaves are a positive sign that a leafcutter bee is nesting in that hole. Some leafcutter bees will nest in thick-stemmed plants (such as roses and bamboo) with hollowed openings. You can prevent nesting in rose canes by sealing pruned ends with wax (sealing or candle), thumbtacks, wooden dowels or white glue (a drop or two will do).

For other Extension publications:

http://www.ext.colostate.edu/pubs/insect/05576.html

0