Dr. Scott Ludwig and other IPM specialists have embarked in a search for an economically sound means of controlling the pests, which puts part of the East Texas $225 million-a-year nursery industry at risk. The pest also poses a risk to pecan orchards and other species, such as redbud, ornamental pears and red oaks.

"We have some growers who have lost whole species of trees this year. I heard very little about the beetle from the growers the first two years I was here," said Ludwig, who has been working in East Texas for three years.

Ludwig has launched an two-fold emergency program to deal with the threat. One program, funded by the U.S. Department of Agriculture, is the testing of a new preventative trunk spray at two nurseries. The other is a trapping survey to find out just how deeply the Asian ambrosia beetle is entrenched in East Texas. Ludwig designed the survey to monitor when the adults emerge from the trees and determine what other species of ambrosia beetle are present.

Ambrosia beetles are so named because they cultivate the ambrosia fungus inside the tree. The pest does so for the same reason that a number of ant species farm fungi, to produce food. The fungus plugs up the tree's vascular system, the collection of tiny vessels that transports water and nutrients to the plant cells.

"It's really the ambrosia fungus that kills the tree, not the beetle," Ludwig said. No one knows why the insect made such an impact this year, but Ludwig said it's suspected that mild winters have played a big role. The adult beetles over-winter in leaf litter, and warmer winters could result in more surviving to emerge in the spring, he said. "But that'
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Contact: Robert Burns
rd-burns@tamu.edu
903-834-6191
Texas A&M University - Agricultural Communications
6-May-2004