Dave Mather IPS Engraver Beetles

    Lindy and I had finished all our projects last time we were "down-to-camp" in northern Florida. So, this November we were ready for some real R & R. Unfortunately, a gang of critters called the IPS Engraver Beetles had made other plans. In 6 months, these 1/8" long, roundish-shaped, and dark colored beetles with spiny hollowed-out butts had killed 7 of our 60' tall slash pine trees. I immediately contacted the local Florida state "service" forester and set up a meeting to find out what was going on.
    I learned that the beetle likes weakened trees. Although rain has been plentiful lately, Florida had been very dry for a couple of years. A drought can weaken a tree's ability to produce pitch that physically and chemically protects it. The attack begins with the male who gets into the inner bark where he excavates small "nuptial chambers". He releases an odor doing this, which attracts the females. After mating, the female digs an egg "gallery" along the inner bark. Several days later, the eggs hatch and mature 1/4" larvae feed on the inner bark before they develop into pupae. As adults, they feed on blue stain fungi that commonly accompany an infestation. The tunnel or "gallery" activity affects the food transporting phloem, and the blue staining fungi, which the beetles carry into the sapwood, plug the water transporting xylem. The adults later exit through 1/16" - 1/8" holes that look like someone shot the tree with birdshot. Affected trees show needle color changes from green to yellow to red to brown and then they fall off. There are 8 - 10 generations of beetles annually, most occurring during warmer temperatures. Unlike other Florida pine beetles that wipe out whole stands, the IPS (thank goodness) jumps around indiscriminately. We learned it's a good idea to remove the infected trees. so Lindy and I once again had plenty to do during "vacation".


© 2002 by David Mather. All rights reserved. No parts of this publication may be reproduced in any form or by any means without the written permission of the author.