Table 1.
Analysis of heat-inactivated dried yeast pellet activity.
| a. LD50 of dried yeast formulations | ||||||
|---|---|---|---|---|---|---|
| Yeast | N | LD50 (mg) | 95% confidence limit (mg) | |||
| Lower | Upper | |||||
| #52 | 45 | 31.07 | 27 | 35.03 | ||
| #101 | 33 | 33.41 | 28.73 | 38.04 | ||
| b. Dried yeast formulation activity in containers with varying water volumes/larval densities | ||||||
| Water volume (L) | Water depth (cm) | Number of larvae | Yeast (mg) | Yeast | Mean mortality induced | SEM |
| 0.050 | 1.7 | 20 | 85 | Control | 3.33%a | 1.36% |
| #52 | 86.67%b | 1.57% | ||||
| #101 | 87.78%b | 1.14% | ||||
| 1.50 | 2 | 100 | 425 | Control | 5.67%c | 1.28% |
| #52 | 83.67%d | 1.41% | ||||
| #101 | 86.17%d | 1.46% | ||||
| 15.75 | 26 | 80 | 340 | Control | 45.83%e | 7.61% |
| #52 | 95.63%f | 2.14% | ||||
| #101 | 95.00%f | 2.20% | ||||
| c. Residual activities of dried yeast formulations | ||||||
| Yeast | Week 0 | Week 1 | Week 2 | |||
| Mean mortality | SEM | Mean mortality | SEM | Mean mortality | SEM | |
| Control | 6.11%g | 1.72% | 7.78%i | 2.95% | 6.27%k | 2.94% |
| #52 | 90.00%h | 1.11% | 54.44%j | 2.99% | 7.78%k | 2.24% |
| #101 | 93.33%h | 1.57% | 55.56%j | 5.00% | 13.33%k | 3.77% |
LD50 values and confidence intervals (a), larvicide activities in varying container sizes/larval densities (b), and larvicide residual activities (c) are shown for dried inactivated larvicide #52 and #101 yeast tablets vs. control interfering RNA tablets. For each experiment (treatments at the indicated water volumes/larval densities in b or residual activities at the indicated time points in c), means in the same column followed by different letters are significantly different (P = 1.0 × 10−5). No differences in mortality were noted between control interfering RNA yeast-fed animals (a-c) vs. animals fed a normal laboratory diet that were reared in parallel (not shown). No significant differences were detected between containers treated with larvicides #52 vs. #101 in a-c. SEM = standard error of the mean. Information concerning n numbers for each experiment is detailed in the methods section.