Table 2.
Parameter estimates for a negative binomial model explaining the abundance of all Phlebotomine sand fly species in Trinidad de las Minas, Capira District, Panamá
| Parameter | Proportional abundance change | Estimate | S.E. | z | Pr(>|z|) |
|---|---|---|---|---|---|
| Control-Peridomicile-Zoophilic |
1(308)¶ |
5.730 |
0.451 |
12.712 |
<0.00001x |
| Domicile |
0.416 |
−0.878 |
0.268 |
−3.274 |
0.00106x |
| Anthropophilic |
0.783 |
−0.245 |
0.302 |
−0.812 |
0.417 |
| Fogged |
0.228 |
−1.477 |
0.282 |
−5.246 |
<0.00001x |
| (S.D. Rain)2 |
1.008 |
0.00875 |
0.00265 |
3.301 |
0.000964x |
| S.D. Rain |
0.795 |
−0.230 |
0.0689 |
−3.338 |
0.000844x |
| Domicile*Anthropophilic |
0.784§ |
0.880 |
0.377 |
2.335 |
0.0195x |
| Fogged*Anthropophilic | 0.482§ | 0.993 | 0.391 | 2.540 | 0.0110x |
xStatistically Significant (P < 0.05). ¶the value inside parenthesis is the estimated abundance for the reference group, i.e., Control-Peridomicile-Zoophilic. * indicates a synergistic (a.k.a. interaction) effect. §To estimate the proportional abundance change of these interactions we considered the value in relation to the estimate for the main factors.
The overdispersion parameter estimate (± S.E.) was 1.217 ± 0.164. The model considered whether a house was fogged or not (Control), the habitat (Domicile or Peridomicile), whether species are known to feed on humans (Anthropophilic) or not (Zoophilic) and a second degree polynomial for the monthly S.D. of daily Rainfall.