Table 1 Summary of snail survey during 2015 to 2019
Year | Area surveyed (ha) | Area infested with snails (ha) | Area of new snail habitats (ha) | Area with snails reemerged in previous habitats (ha) | No. frames surveyed | No. frames with snail | No. dissected living snails | No. infected snails | Percentage of frames with living snails, % (95% CI) | Mean density of living snails, (number of snails per frame, pf) (95% CI) |
|---|---|---|---|---|---|---|---|---|---|---|
2015 | 18,043 | 7271 | 3.5 | 19.7 | 761,492 | 45,152 | 155,622 | 0 | 5.93 (5.88–5.98) | 0.20 (0.17–0.37) |
2016 | 17,832 | 6810 | 136.6 | 74 | 597,849 | 47,045 | 132,968 | 0 | 7.87 (7.80–7.94) | 0.22 (0.18–0.46) |
2017 | 19,241 | 6682 | 0.2 | 88.9 | 680,497 | 41,452 | 105,151 | 0 | 6.09 (6.03–6.15) | 0.15 (0.16–0.44) |
2018 | 19,303 | 6297 | 5 | 112 | 584,072 | 34,819 | 85,508 | 0 | 5.96 (5.90–6.02) | 0.16 (0.16–0.27) |
2019 | 19,822 | 6837 | 0 | 229.8 | 589,583 | 30,947 | 76,144 | 0 | 5.25 (5.19–5.31) | 0.13 (0.11–0.39) |
Total | 94,241 | 33,897 | 145.3 | 524.4 | 3,213,493 | 199,415 | 555,393 | 0 | – | – |