Sunday, August 26, 2012

Pest News for August 27 2012

From: Steve Frank, Extension Entomologist

Azalea Caterpillars

Azalea caterpillars, Datana major, are among our most attractive caterpillar species. They feed primarily on Rhododendron spp. and are most evident late in the summer. There is one generation of this pest each year. Adults lay eggs on the underside of azalea leaves where the small caterpillars feed gregariously. As they grow the caterpillars take on the coloration seen in the picture below. Unfortunately, by the time they are noticed azalea caterpillars can consume a lot of foliage and defoliate a shrub. Scout for these caterpillars by scanning shrubs for bare twigs then look closer to investigate. If you find a group of them just prune the branch out. In larger infestations or nurseries there are several insecticides active on caterpillars but any product works best on small stages.

Information can be found at

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.

Sunday, August 19, 2012

Pest News for week of July 20th


From: Steve Frank, Extension Entomologist

Japanese Maple Scale in the Nursery and Landscape

Japanese maple scale, Lopholeucaspis japonica, is active now and much of the summer. It is a small, oystershell-shaped, armored scale introduced to the U.S. from Asia. Japanese maple scale is found in several eastern U.S. states, including CT, DE, GA, KY, MD, NC, NJ, PA, RI, TN and VA, as well as Washington D.C. Japanese maple scale has a wide host range that in addition to maples (e.g.,  Japanese maples, red maples, paperbark maples, and sugar maples), includes Amelanchier, Camellia, Carpinus, Cercis, Cladrastis, Cornus, Cotoneaster, Euonymus, Fraxinus, Gledistia, Ilex, Itea, Ligustrum, Magnolia, Malus, Prunus, Pyracantha, Pyrus, Salix, Stewartia, Styrax, Syringa, Tilia, Ulmus, Zelkova and others.
Although the lifecycle of this pest has not been fully examined, two generations a year are expected in the mid-southern U.S. First generation crawlers emerge in mid-May, and the second generation in early August. Management efforts are complicated by the extended crawler emergence that results in first and second generational overlap. Thus, the most recent sample we received had every stage - egg to adult - present at the same time.
Adult scales and crawlers are very small and most readily observed on bark of dormant deciduous host plants, but can also be found on foliage. The waxy coating on the body of male Japanese maple scales is white and females, eggs, and crawlers are lavender. The most work on this scale has been done by Paula Shrewsbury and Stanton Gill at the University of Maryland. Paula Shrewsbury recently gave webinar as part of the National IPM Webinar Series run by Kelly Ivors and I. Archived presentations can be found at: See more information on Japanese maple scale and other maple pests in our new book:
A link to the University of Maryland fact sheet is:

Ants Increase Pest Abundance

As you know from family picnics, ants are voracious scavengers of sweets. Although this results in many household problems it can also increase outdoor pest problems. Aphids, mealybugs, soft scales and other sap-suckers drink lots of phloem and excrete the excess as honeydew. Ants will often ‘tend’ these insects and gather each drop of honeydew as it is produced. Ants protect the pests from predators so they can preserve this abundant food source. Many researchers have found that pests become much more abundant when tended by ants and fire ants in particular. Thus if you see a trail of ants going up a tree chances are there are scales or some other pest they are tending. Often by blocking the ants with tangle foot or using fire ant bait you can eliminate the pests. As soon as ants do not protect the pests, natural enemies hammer them.

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.