Termites Go Hungry on Resistant Trees

By Jan Suszkiw
October 12, 2000

Agricultural Research Service scientists in New Orleans, La., have identified 30 types of commercial lumber that attract or repel Formosan subterranean termites, painting a more complete picture of where this invasive pest species is likely to turn up in processed wood.

In termite-plagued Louisiana, for example, builders could use the information to select lumber--such as Western red cedar or Alaskan yellow cedar--that’s less apt to lure the insect into homes. Knowing which types of hardwood or softwood species Formosan termites prefer could also improve the effectiveness of bait products that kill the pests by luring them to slow-acting toxins, according to Juan Morales-Ramos and Guadalupe Rojas, entomologists at ARS’ Southern Regional Research Center in New Orleans.

There, they designed a series of carefully controlled, replicated lab experiments in which termite colonies were fed wooden blocks cut from 30 types of lumber. Wood that termites didn’t like include old growth bald cypress; Western red-, Alaskan yellow-, Eastern red-, and Spanish cedar; mahogany; sassafras; and Indian-, Honduras-, and Bolivian rosewood. In fact, eight of the wood samples actually killed termite colonies during 3-month forced-feeding trials, probably because of noxious chemicals in the wood.

Wood that topped the pest’s favorites in the studies included birch, red gum, Parana pine, sugar maple, pecan and red oak. Each stimulated more termite feeding than southern yellow pine, a control species the scientists used, and a commonly used lumber tree in the South.

Southern yellow pine has also been used as bait to help monitor termites foraging for food. This new information, along with ongoing field studies with living trees, points to other, more attractive woods that should improve such monitoring to control the pest.

The research is part of an ARS-led national campaign called Operation FullStop to fight the termite, and minimize its damage. A longer article about their bait and other Operation FullStop tactics is in this month’s issue of Agricultural Research magazine.

Scientific contact: Juan Morales-Ramos and Guadalupe Rojas, Formosan Subterranean Termite Research Unit, ARS Southern Regional Research Center, La., phone (504) 286-4256 (Morales-Ramos), (504) 286-4382 (Rojas); fax (504) 286-4419; jmorales@commserver.srrc.usda.gov, rojas@commserver.srrc.usda.gov.