Table 6.
Effects of Bacillus sphaericus (Griselesf®) on densities of late instars of An. gambiae complex and percent reduction in “mosquito spheres” trials during three subsequent treatments (T) with varying doses
| Day | Average number per dip |
Percentage reduction |
|||||
|---|---|---|---|---|---|---|---|
| Late instars |
Late instars |
||||||
| Control | T1 | T2 | T3 | T1 | T2 | T3 | |
| 0a | 25.0 | 25.0 | 25.0 | 25.0 | – | – | – |
| 1 | 12.6A | 0.2B | 0B | 0B | 98.4 | 100 | 100 |
| 3 | 11.6A | 3.2B | 0B | 0.4B | 72.4 | 100 | 96.6 |
| 5 | 22.6A | 3.2B | 2.0B | 0B | 85.8 | 91.2 | 100 |
| 7 | 18.8A | 4.6A | 7.4A | 3.0A | 75.5 | 60.6 | 84.0 |
Notes: In each row, larval density figures sharing the same superscript letter do not differ significantly.
Abbreviations: T1: minimum label rate (5 ml/m2); T2: maximum label rate (10 ml/m2); T3: twice the maximum label rate (20 ml/m2).
a
The first batch of 25 An. gambiae complex larvae were introduced in the treatment tubs and application of Bs; a new batch of 25 larvae were introduced on days 2, 4 and 6 (not shown).