Tuesday, December 11, 2007 - 4:11 PM
1106

Evaluation of tunneling behavior, penetration rate, and efficacy of a glycol borate for remedial control of subterranean termites (Isoptera: Rhinotermitidae)

Roger E. Gold, r-gold@tamu.edu, Texas A&M University, Dept. of Entomology, 2143 TAMU, College Station, TX and James Austin, jwaustin@ag.tamu.edu, Texas A&M University, Department of Entomology, 2143 TAMU, College Station, TX.

Recent concerns over the use of glycolated borates for preventative treatments on newly constructed urban dwellings as “stand alone” treatments, historical evidence from competing studies, and a general incongruence from manufacturer’s marketing claims, have prompted a one-year study to evaluate the overall efficacy of boron (in the form of disodium octaborate tetrahydrate or DOT) treatments in the state of Texas. Repeated measures analysis of penetration rates into southern yellow pine (SYP) wood evaluated by inductively coupled plasma-optical emission spectrometry (ICP-OES), and with lab tunneling and exposure bioassays for both Reticulitermes flavipes (Kollar) and Coptotermes formosanus Shriaki have resulted with mixed results in this application technology. Penetrations rates for DOT into SYP maintained at 29C and 100% RH resulted with SYP centroids almost 10-fold and 5-fold below established LD50 values for C. formosans and R. flavipes, respectively. However, mortality remained high in treated bioassays and tunneling was not generally observed under laboratory conditions. Results support other research which demonstrates the limitations of penetration of boron into wood, even under ideal conditions. The efficacy of boron treated SYP consistently killed and inhibited over-tunneling by subterranean termites to treated surfaces, while center cut wood (from exterior treated SYP) assays confirm poor penetration of DOT into wood and the subsequent inability to consistently kill termites. These results support glycolated borates ability to kill termites when directly exposed, but demonstrate the need for caution when considering this technology in lieu of other contemporary treatment options for either remedial or preventative applications in urban use scenarios.


Species 1: Isoptera Rhinotermitidae Reticulitermes flavipes (eastern subterranean termite)
Species 2: Isoptera Rhinotermitidae Coptotermes formosanus (Formosan subterranean termite)