Figure 1Distribution of mosquitoes and Culex tritaeniorhynchus (CT) per year.
Figure 2Autocorrelation.
Figure 3Outofsample results used in rolling window regression (weekly data). CT, Culex tritaeniorhynchus. RC: Rolling window regression of CT.
Figure 4Outofsample results used in adding window regression (weekly data). CT, Culex tritaeniorhynchus. AC: Adding window regression of CT.
Table 1Unit root test (level variables).
Weekly data 
ADF

PP

None 
Intercept 
Trend 
None 
Intercept 
Trend 
All mosquitoes 
−5.423* 
−6.190* 
−6.246* 
−5.655* 
−6.672* 
−6.751* 
Culex tritaeniorhynchus

−8.786* 
−9.529* 
−9.549* 
−6.862* 
−7.708* 
−7.720* 
Ratio 
−6.177* 
−7.340* 
−7.336* 
−5.771* 
−6.708* 
−6.705* 
Table 2Basic statistical data on mosquito density.
Variables 
Mean 
Maximum value 
Minimum value 
Standard deviation 
All mosquitoes 
7846.3(562.9)* 
87,194.0 
0.0 
14,635.1 
Culex tritaeniorhynchus

1991.9(217.0)* 
58,769.0 
0.0 
5641.4 
Ratio 
10.2(0.7)* 
73.4 
0.0 
17.7 
Table 3Time lag test.
Variables 
All mosquitoes 
Culex tritaeniorhynchus

Ratio of Culex tritaeniorhynchus to all mosquitoes 
Test method 
AIC 
SIC 
AIC 
SIC 
AIC 
SIC 
Time lag 
10 
1 
4 
4 
9 
4 
Table 4Autoregressive model estimation (weekly data).
Variable 
Last year 
2 years ago 
3 years ago 
4 years ago 
R^{2}

All mosquitoes 
0.435(0.044)** 
0.269(0.054)** 
−0.024(0.056) 
0.310(0.055)** 
0.637 
Japanese encephalitis 
0.138(0.043)** 
0.353(0.043)** 
0.189(0.050)** 
0.068(0.049) 
0.394 
Ratio of Japanese encephalitis 
0.162(0.044)** 
0.381(0.041)** 
0.381(0.044)** 
−0.085(0.045)*** 
0.717 
Table 5MSE of insample.

Insample prediction

All mosquitoes 
Culex tritaeniorhynchus

Ratio 
MSE 
8.881 × 10^{7}

1.851 × 10^{7}

84.823 
Table 6MSPE of outofsample prediction.

Outofsample prediction

All mosquitoes 
Culex tritaeniorhynchus

Ratio of Culex tritaeniorhynchus

MSPE (RO) 
2.045 × 10^{8}

8.852 × 10^{7}

86.069 
MSPE (AD) 
5.229 × 10^{7}

3.476 × 10^{7}

78.351 