Submitted to: Journal of Chemical Ecology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/5/2004
Publication Date: 3/20/2005
Citation: Raina, A.K., Bland, J.M., Osbrink, W.L. 2005. Is hydroquinon a phagostimulant for the formosan subterranean termite. Journal of Chemical Ecology 31: 509-517. Interpretive Summary: The Formosan subterranean termite (FST) is a major structural pest in several southern states of the U.S., causing over a billion dollars annually in prevention and repair costs. The newer technology involving use of baits for colony elimination is dependent upon termites first finding the bait station. Hydroquinone, a chemical found in many termite species was reported to be an attractant as well as a feeding stimulant. Our objective was to test these claims for FST, both under laboratory and field conditions. We did find small quantities of hydroquinone in FST. However, it was not attractive at any of the wide range of test concentrations, nor did it cause an increase in feeding. Hydroquinone also did not effect tunneling through treated sand. At higher concentrations, the chemical was a repellent. This research has shown that hydroquinone alone can not be used as an attractant/feeding stimulant in FST baits. The information would be useful to termite researchers as well as those involved in termite control operations.
Technical Abstract: Through a series of publications it has been suggested that labial glands of a number of termite species contain hydroquinone that acts as a primary phagostimulating factor. We tested hydroquinone as a phagostimulant for the Formosan subterranean termite, Coptotermes formosanus, in tests carried out both in the laboratory and the field. Hydroquinone at concentrations ranging from ca. 0.002 - 20.0 ng/cm2 did not evoke preferred visitation by C. formosanus workers to treated filter papers over control papers. On the other hand, the compound was repellent at the 20 ng/cm2 dose. Similarly, no phagostimulant response was observed except for workers from one of the test colonies at the 2 ng/cm2 dose. Also, sand treated with a gradient of hydroquinone, did not evoke increased tunneling activity. GC-MS analysis of C. formosanus workers indicated that hydroquinone, indeed, was present at an average of 41pg/worker. It was also determined that within one week about 11% hydroquinone in aqueous solution oxidized to 1,4-benzoquinone. Thus, hydroquinone did not act as a phagostimulant but instead was a strong repellent at higher concentrations. The attractant/arrestant in the Formosan termite may very well have multiple components of which hydroquinone, at very low doses, could be on of the components.