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United States Department of Agriculture

Agricultural Research Service


item Puche, Helena
item Su, Nan Yao

Submitted to: Bulletin of Entomological Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2003
Publication Date: 2/1/2004
Citation: Puche, H., Su, N. 2004. Estimating population density of the formosan subterranean termite, coptotermes formosanus(isoptera:rhinotermitadae) using the effective sampling area of in-ground monitoring stations. Bulletin of Entomological Research. 94:47-53.

Interpretive Summary: Subterranean termites are considered the most economically important structural pest in the United States, accounting for up to $1.2 billion in damage and treatment costs each year. Recent developments for detection, control, and monitoring of subterranean termites include the use of monitoring-baiting programs. Usually, termites infest some monitoring stations over time and the colony is eliminated by subsequent bait application, but termites intercept only a few stations. Scientists from the Subtropical Horticulture Research Station and the University of Florida determined the effectiveness of monitoring stations in capturing the Formosan subterranean termite. The investigation showed that an average of one trap is needed every 3 to 7 m2 to estimate the size of these colonies. This information will be used to determine the number of monitoring stations that are needed to estimate the population size of the termite colony. The results will be used by the pest control industry to improve decisions for termite management by optimizing monitor-bait programs and thus reducing the cost of termite control.

Technical Abstract: The effective sampling area of a trap, (a), was chosen to determine the effectiveness of monitoring stations to detect populations of subterranean termites. Data from previous mark recapture studies, in Broward County, Florida, using seven colonies of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) were used to calculate a for each colony. Stake surveys were used to detect underground termite activity by partially burying 200 wooden stakes every 5 meters in lawns and planters around buildings attacked by subterranean termites for each colony or site. Only those stakes that were attacked by subterranean termites were replaced by in - ground monitoring stations. Termites collected from monitoring stations from all sites were brought to the laboratory, and marked with Nile Blue. An average of 4,568 marked termites were released into the monitoring station that had the highest termite activity at each site or colony. Seven days after release, active traps in the vicinity were brought to the laboratory and marked and unmarked termites identified and counted. Average recapture probability was 0.005 close to the release point (< 5 m) and declined to 0.0008 at a distance of 51 to 60 m. For each site, recapture rates were not significantly affected by distance. The effective sampling area (a) was obtained, and ranged from 0.607 m2 for colony I, to 14.5 m2 for colony IV. For management purposes, an average of one trap is needed every 3 to 7 m2 to estimate the size of these colonies. The effective sampling area estimated in this study, should be taken as an excellent estimator that translates subterranean termite catches from in-ground monitoring stations into foraging termite population density. The concept of the effective sampling area can be used for quantitative comparisons of subterranean termites or any other cryptic insects in relation to seasonality, age, treatment effects, or to validate other protocols used to estimate population density.

Last Modified: 08/16/2017
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