Table 3.
Selected characteristics of examined stormwater drains and catch basins in Mérida City, for all zones and months combined, in relation to the total number of Ae. aegypti and Cx. quinquefasciatus immatures collected.
| Characteristic of stormwater drain and catch basin (no. examined for specific characteristic) | No. (%) with characteristic | No. (%)Ae. aegypti immatures collected | No. (%) Cx. quinquefasciatus immatures collected |
|---|---|---|---|
| Size (1,761)a | |||
| Small | 19 (1.1) | 344 (1.5) | 418 (1.1) |
| Medium | 1,724 (97.9) | 21,342 (91.5) | 32,957 (83.9) |
| Large | 18 (1.0) | 1,627 (7.0) | 5,894 (15.0) |
| Drainage pipe (1,761) | |||
| Missing | 739 (42.0) | 19,111 (82.0) | 20,011 (51.0) |
| Vertical | 317 (18.0) | 452 (2.0) | 3,313 (8.4) |
| Horizontal | 705 (40.0) | 3,750 (16.0) | 15,945 (40.6) |
| Well (connected to drainage pipe if this is present) (1,761) | |||
| Present | 419 (23.8) | 1,081 (4.6) | 6,839 (17.4) |
| Absent | 1,342 (76.2) | 22,232 (95.4) | 32,430 (82.6) |
| Status of walls (1,761) | |||
| Finished and impermeable | 878 (49.9) | 8,488 (36.4) | 11,929 (30.4) |
| Unfinished and permeable | 883 (50.1) | 14,825 (63.6) | 27,340 (69.6) |
| Trash items (1,761) | |||
| Present | 402 (22.8) | 15,956 (68.4) | 22,401 (57.0) |
| Absent | 1,359 (77.2) | 7,357 (31.6) | 16,868 (43.0) |
| Water quality (262)b | |||
| Clear | 54 (20.6) | 5,503 (23.6) | 8,638 (22.0) |
| Turbid | 208 (79.4) | 17,810 (76.4) | 30,631 (78.0) |
| Water odor (262)b | |||
| Present | 139 (53.0) | 13,717 (58.8) | 19,177 (48.8) |
| Absent | 123 (47.0) | 9,596 (41.2) | 20,092 (51.2) |
| Water volume (262)b | |||
| ≤10 liters | 27 (10.3) | 799 (3.4) | 994 (2.5) |
| >10 liters | 235 (89.7) | 22,514 (96.6) | 38,275 (97.5) |
| Water pH (262)b | |||
| ≤7 | 102 (38.9) | 7,671 (32.9) | 17,306 (44.1) |
| >7 | 160 (61.1) | 15,642 (67.1) | 21,963 (55.9) |
| Water temperature (262)b | |||
| ≤25 °C | 12 (4.6) | 68 (0.3) | 7,343 (18.7) |
| 26–27 °C | 68 (25.9) | 11,325 (48.6) | 11,079 (28.2) |
| 28–29 °C | 153 (58.4) | 11,063 (47.4) | 20,093 (51.2) |
| ≥30 °C | 29 (11.1) | 857 (3.7) | 754 (1.9) |
| Percentage of shade (262)b | |||
| 0% | 217 (82.8) | 18,594 (79.8) | 26,165 (66.7) |
| 25% | 22 (8.4) | 2,270 (9.7) | 4,450 (11.3) |
| 50% | 19 (7.3) | 2,164 (9.3) | 4,554 (11.6) |
| 100% | 4 (1.5) | 285 (1.2) | 4,100 (10.4) |
| Types of organic matter present (262)b | |||
| Primarily wood | 2 (0.7) | 165 (0.7) | 39 (0.1) |
| Primarily grass | 7 (2.7) | 440 (1.9) | 1,179 (3.0) |
| Primarily leaves | 197 (75.2) | 21,202 (90.9) | 33,792 (86.0 ) |
| Primarily fruits | 7 (2.7) | 385 (1.7) | 2,811 (7.2) |
| Primarily flowersUnrecognizable | 6 (2.3)43 (16.4) | 772 (3.3)349 (1.5) | 641 (1.6)806 (2.1) |
| Status of organic matter (262)b | |||
| Primarily intact | 156 (59.5) | 21,668 (92.9) | 27,433 (69.9) |
| Primarily decomposed | 106 (40.5 ) | 1,645 (7.1) | 11,836 (30.1) |
a
Small: ~1.0 m length × 0.5 m width × 0.7 m depth; Medium: ~ 2.0 m length × 0.5 m width × 0.7 m depth; Large: ~ 4.0 m length × 0.5 m width × 0.7 m depth.
b
Based on 262 stormwater drains and catch basins that held water at the time they were examined.