## 3 Results  
The field test results proved that the monitoring system and device described here is practical to detect termite activity used at termite bait stations. A total of 40, 200, and 250 baiting stations have been installed at three test sites (LA, HZ and TX). Results at three test sites showed that the accuracy rate was 97.5%, 98.5%, and 98.4%, respectively, at 24 months after installation. Among the stations showing positive signals, there was a more than 95% accuracy rate. After 24 months of application, only one, three, and four stations failed to show true signals at three test sites, respectively, and more than 97% circuit boards were in good condition and fully functioning. The accuracy of monitoring data from the three test sites is presented in Table 1.  
There were 40 stations installed in the LA test site (LA). After 2 years, 4 stations showed warning signals for termite presence. Either termites or wood pieces destroyed by termites were found at all these four stations after manual checking. The results also showed that 97.5% of the circuit boards retained their integrity at 24 months after installation, which means these electronic boards have a lifetime of more than 24 months.  
At the HZ test site, 200 stations were installed. At 18 months, 151 stations showed true negative results, and 47 stations showed true positive results. One station was false negative, and one station was false positive. At 24 months, 148 stations showed true negative results, 49 stations showed true positive results, 2 stations were false negative, and 1 station was false positive. The accuracy rate of the monitoring system after 18-month and 24-month installation was 99.0% and 98.5%, respectively. Among the stations showing positive signals, 98.0% of stations showed true positive results.  
250 stations were installed at the TX test site. Five baiting stations could not be found due to construction after 21 months of operation. At the remaining 245 stations, 4 stations  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline
**Site** & **Months** & **TN** & **TP** & **FN** & **FP** & **AR\%** & **ARP\%** & **Z** & **P** \\ \hline \multirow{6}{*}{LA} & 3 & 39 & 1 & 0 & 0 & 100 & 100 & & \\  & 6 & 38 & 2 & 0 & 0 & 100 & 100 & & \\  & 9 & 38 & 2 & 0 & 0 & 100 & 100 & & \\  & 12 & 37 & 3 & 0 & 0 & 100 & 100 & \(-\)2.1602 & 0.0004678 \\  & 15 & 36 & 4 & 0 & 0 & 100 & 100 & & \\  & 18 & 36 & 4 & 0 & 0 & 100 & 100 & & \\  & 21 & 35 & 4 & 1 & 0 & 97.5 & 100 & & \\  & 24 & 35 & 4 & 1 & 0 & 97.5 & 100 & & \\ \hline \multirow{6}{*}{HZ 200 stations} & 3 & 189 & 11 & 0 & 0 & 100 & 100 & & \\  & 6 & 185 & 14 & 1 & 0 & 99.0 & 100 & & \\  & 9 & 173 & 25 & 1 & 1 & 99.0 & 96.1 & & \\  & 12 & 156 & 42 & 1 & 1 & 99.0 & 97.7 & \(-\)8.641 & 0.0006371 \\  & 15 & 153 & 45 & 1 & 1 & 99.0 & 97.8 & & \\  & 18 & 151 & 47 & 1 & 1 & 99.0 & 98.0 & & \\  & 21 & 149 & 48 & 2 & 1 & 98.5 & 98.0 & & \\  & 24 & 148 & 49 & 2 & 1 & 98.5 & 98.0 & & \\ \hline \multirow{6}{*}{TX 250 stations} & 3 & 248 & 2 & 0 & 0 & 100 & 100 & & \\  & 6 & 240 & 10 & 0 & 0 & 100 & 100 & & \\  & 9 & 234 & 14 & 2 & 0 & 99.2 & 100 & & \\ \cline{1-1}  & 12 & 209 & 38 & 1 & 2 & 98.8 & 95.0 & \(-\)5.945 & 0.0008446 \\ \cline{1-1}  & 15 & 207 & 40 & 1 & 2 & 98.8 & 95.2 & & \\ \cline{1-1}  & 18 & 201 & 46 & 1 & 2 & 98.8 & 95.8 & & \\ \cline{1-1}  & 21 & 195 & 46 & 2 & 2 & 98.4 & 95.8 & & \\ \cline{1-1}  & 24 & 194 & 47 & 2 & 2 & 98.4 & 95.9 & & \\ \hline \end{tabular}  
* TN (true negative), information bar intact (no alarm) and absence of termites; TP (true positive), alarm signal (red spot) and presence of termites or wood pieces attacked by termites; FN (false negative), no alarm with the presence of termites or no alarm when stations were destroyed; FP (false positive), alarm signal (red spot) and absence of termites.  
\end{table}
Table 1: Performance of the system for detecting termite activities during a 24-month period.  
(1.6%) showed false signals, and all other stations (98.4%) either were true negative or true positive after 24 months of operation.