Table 7.
Ovicidal activity of isobutyrylshikonin and isovalerylshikonin against Tetranychus urticae.
| Dose μg·cm−2 | Isobutyrylshikonin | Isovalerylshikonin | ||||||
|---|---|---|---|---|---|---|---|---|
| Mortality of Eggs (%) a | ED50 b (CI95) | ED90 b (CI95) | Chi c | Mortality of Eggs (%) a | ED50 b (CI95) | ED90 b (CI95) | Chi c | |
| 13.5 | 58.9 ± 6.5 | 9.7 (7.8–12.8) |
60.6 (58.9–92.2) |
1.546 | 100.0 ± 0.0 | 2.1 (1.7–2.3) |
5.4 (4.5–7.6) |
1.478 |
| 6.8 | 43.3 ± 5.5 | 95.6 ± 7.6 | ||||||
| 3.4 | 18.6 ± 3.9 | 70.7 ± 3.8 | ||||||
| 1.7 | 10.5 ± 3.6 | 42.3 ± 5.2 | ||||||
| 0.8 | 5.3 ± 0.8 | 27.3 ± 5.9 | ||||||
| Control | 1.2 ± 0.2 | 1.2 ± 0.2 | ||||||
a The average mortality (in %) of eggs after treatment with the compounds isobutyrylshikonin and isovalerylshikonin ± standard deviation (S.D.); b Effective dose ED50 (ED90) in μg·cm−2 causing 50% (90%) mortality of eggs of T. urticae, CI95 = 95% confidence intervals, extract activity is considered significantly different when the 95% CI fail to overlap; c Chi-square value, not significant at p > 0.05 level.