J. M. Conner

Management of subterranean termites, Reticulitermes spp. (Isoptera: Rhinotermitidae) in a citrus orchard with hexaflumuron bait

The eastern subterranean termite, Reticulitermes yavipes (Kollar) is a pest of young citrus in Florida, killing trees by girdling at or just below the soil line. Reticulitermes virginicus (Banks), another inhabitant of citrus groves, may cause similar damage. Chemical and cultural methods developed previously to create barriers to termites around young citrus trees provided temporary or incomplete control. However, baiting systems may provide longer lasting control by eliminating or at least reducing termite activity. Triple mark}recapture with Nile blue dye was used to delineate foraging ranges and to estimate populations sizes of two R. yavipes and one R. virginicus colony located in two di!erent blocks of a south Florida citrus grove. This dye has been observed to be detectable from 6 to 9 months after ingestion by subterranean termites, and not to be transferred between individuals by tropholaxis (Su, unpublished data). Termite activity was monitored by counting workers and estimating wood consumption at buried monitoring stations. Termites were recruited to bait stations initially containing spruce wood which was then replaced with 0.1 or 0.5% hexa#umuron in either a particulate (wood #our) or non-particulate (paper) cellulose matrix and consumption was monitored. After a 2}3 month baiting period, no new termite activity was detected within the areas of baited R. yavipes. Similar amounts of toxicant were consumed per termite in all cases. No subsequent tree injury was observed within the areas of the baited colonies. Baiting with hexa#umuron appears to be a viable alternative for managing subterranean termites in citrus and possibly other agricultural systems. ( 2001 Published by Elsevier Science Ltd.