Table 1.
Toxicity of the Cyt1Aa-BinA chimera and control strains of Bacillus thuringiensis subsp. israelensis (Bti) and Lysinibacillus sphaericus (Ls) to 4th-instars of Aedes, Anopheles and Culex species at 24 hours post-treatmenta.
| Bacterial Strain (Toxins produced) | LC50 (Fiducial Limits) | RTd-LC50 | LC95 (Fiducial Limits) | RTd-LC95 | Slope |
|---|---|---|---|---|---|
| Culex quinquefasciatus S-Lab | |||||
| Bti 4Q7/pWF45 (Cyt1Aa) | 47,370.1 (35,629.5–59,705.4) | 6,671 | 155,050.3 (114,040.8–260,168.4) | 1,914.2 | 3.2 ± 0.5 |
| Ls 2362 (BinAB) | 181.4 (118.1–296.3) | 25.6 | 7,569.4 (3,009.6–33,192.5) | 93.5 | 1.0 ± 0.1 |
| Bti 4Q7/cyt1Aa-binA (Cyt1Aa-BinA chimera) | 9.2 (7.2–12.1) | 1.3 | 30.5 (20.2–71.2) | 0.4 | 3.2 ± 0.6 |
| Bti 4Q5 (Cry4A, Cry4B, Cry11A, Cyt1A) | 7.1 (2.6–18.6) | 1.0 | 81.0 (16.7–427.3) | 1.0 | 1.6 ± 0.4 |
| Culex quinquefasciatus BS-Rb | |||||
| Bti 4Q7/pWF45 (Cyt1Aa) | 27,022.4 (20,523.2–35,262.4) | 5,630 | 100,175.2 (70,685.6–169,448.0) | 4,595.2 | 2.9 ± 0.4 |
| Ls 2362 (BinAB) | >1,000,000c | >208,333 | >1,000,000c | >45,872 | — |
| Bti 4Q7/cyt1Aa-binA (Cyt1Aa-BinA chimera) | 10.2 (2.6–41.4) | 2.1 | 42.0 (2.2–1,214.9) | 1.9 | 2.7 ± 1.0 |
| Bti 4Q5 (Cry4A, Cry4B, Cry11A, Cyt1A) | 4.8 (3.5–6.3) | 1.0 | 21.8 (14.4–45.3) | 1.0 | 2.5 ± 0.4 |
| Aedes aegypti | |||||
| Bti 4Q7/pWF45 (Cyt1Aa) | 4,218.7 (2,997.1–5,709.8) | 1,172 | 22,764.9 (14,634.9–48,334.1) | 84 | 2.3 ± 0.4 |
| Ls 2362 (BinAB) | >1,000,000 | >277,778 | >1,000,000 c | >3,689 | — |
| Bti 4Q7/cyt1Aa-binA (Cyt1Aa-BinA chimera) | 61.9 (46.7–80.1) | 17.2 | 271.1 (185.1–513.4) | 14.7 | 2.6 ± 0.4 |
| Bti 4Q5 (Cry4A, Cry4B, Cry11A, Cyt1A) | 3.6 (2.5–4.8) | 1.0 | 18.5 (11.9–39.6) | 1.0 | 2.3 ± 0.4 |
| Anopheles gambiae | |||||
| Bti 4Q7/pWF45 (Cyt1Aa) | 46,557.3 (13,980.9–137,613.6) | 1,757 | 129,978.8 (25,520.6–923,387.1) | 1,465.4 | 3.7 ± 1.4 |
| Ls 2362 (BinAB) | 201.2 (154.6–260.4) | 7.6 | 1,150.9 (760.7–2,206.5) | 13 | 2.2 ± 0.3 |
| Bti 4Q7/cyt1Aa-binA (Cyt1Aa-BinA chimera) | 23.0 (17.6–30.0) | 0.9 | 80.9 (57.4–135.4) | 0.9 | 3.0 ± 0.4 |
| Bti 4Q5 (Cry4A, Cry4B, Cry11A, Cyt1A) | 26.5 (20.2–34.3) | 1.0 | 88.7 (63.9–144.8) | 1.0 | 3.1 ± 0.4 |
| Anopheles stephensi | |||||
| Bti 4Q7/pWF45 (Cyt1Aa) | 7,779.5 (6,758.9–9,028.8) | 526 | 13,722.2 (11,212.0–20,809.5) | 195 | 6.7 ± 1.3 |
| Ls 2362 (BinAB) | 707.5 (620.3–808.5) | 48 | 1,179.2 (992.0–1,618.5) | 17 | 7.4 ± 1.3 |
| Bti 4Q7/cyt1Aa-binA (Cyt1Aa-BinA chimera) | 28.9 (22.0–37.2) | 1.9 | 93.1 (67.8–149.8) | 1.3 | 3.2 ± 0.4 |
| Bti 4Q5 (Cry4A, Cry4B, Cry11A, Cyt1A) | 14.8 (11.1–19.8) | 1.0 | 70.4 (46.8–133.2) | 1.0 | 2.4 ± 0.3 |
a24 hr-mortality, ng/ml. bLaboratory strain selected for high-level resistance to the binary toxin (Bin) of Ls 2362. cNo mortality at 1 mg/ml. dRelative toxic values of recombinant Bti strains and Ls 2362 against mosquito larvae when compared to strain Bti 4Q5.