Table 1.
Aphid toxicity of Cyt2Aa, CGALn, and CGSLn
| Toxin | LC50 ± SE, μg/mL (CL 95%) |
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| Mosquito larvicidal activity |
Aphicidal activity |
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| Ae. aegypti | Relative LC50 | A. pisum | M. persicae | ||||
| Cyt2Aa | 0.37 ± 0.07 | (0.21–0.90) | 1 | >>150 ± 0.00 | (NA) | >>150 ± 0.00 | (NA) |
| CGAL1 | 0.22 ± 0.04 | (0.06–0.43) | 0.58 | 19.71b ± 5.74 | (2.51–21.00) | 58.04 ± 2.08 | (35.01–65.73) |
| CGAL3 | 0.62 ± 0.04 | (0.24–1.30) | 1.68 | 9.55a ± 2.54 | (0.65–12.23) | 42.68 ± 0.49 | (17.18–83.04) |
| CGAL4 | 0.18 ± 0.05 | (0.01–0.82) | 0.49 | 11.92a ± 1.99 | (0.83–22.43) | 92.75 ± 2.54 | (34.67–152.96) |
| CGSL1 | 0.36 ± 0.06 | (0.19–0.79) | 0.97 | 28.74b ± 2.92 | (6.40–93.40) | ND | |
| CGSL4 | 0.40 ± 0.05 | (0.12–0.91) | 1.09 | 15.13a ± 0.23 | (4.3–25.60) | ND | |
Mortality resulting from aphid ingestion of the five modified toxins that retained toxicity against mosquito larvae was significantly higher than mortality following Cyt2Aa ingestion for A. pisum and three (CGAL1, CGAL3, and CGAL4) for M. persicae (one-way ANOVA, P < 0.001). Significant differences in modified toxin LC50 values for A. pisum are indicated by different letters (a and b). CGAL1, CGAL3, and CGAL4 were significantly more toxic to A. pisum than to M. persicae (one-way ANOVA, P < 0.005). A total of 360 second instar aphids were used for each toxin, with mortality scored after 4 d. LC50 values presented are representative of data from three replicate bioassays. CGSL3 was not included in the aphid feeding assays due to instability of this toxin. ND, not determined.