Table 3.
Biochemical effects of technical and formulated malathion and spinosad at their LC50 values on the AChE, CaE, and GST in Culex pipiens larvae after 24 hours of the treatment
| Treatment | Specific activity (ΔOD min−1×mg−1protein) ± SE
|
% Inhibition
|
||||
|---|---|---|---|---|---|---|
| AChE | CaE | GST | AChE | CaE | GST | |
| Control (untreated capsules) | 5.49±0.2a | 2.98±0.08a | 1.23±0.09a | 0.00 | 0.00 | 0.00 |
| Technical malathion (LC50 =1.108 mg/L) | 0.34±0.01d | 0.00±0.00d | 0.17±0.01d | 93.78 | 100 | 86.10 |
| Formulated malathion (LC50 =4.407 mg/L) | 0.7±0.02c | 1.17±0.02c | 0.44±0.02c,d | 87.25 | 60.73 | 64.80 |
| Technical spinosad (LC50 =0.075 mg/L) | 0.69±0.03c | 0.53±0.06b | 0.25±0.00b | 87.36 | 82.12 | 79.31 |
| Formulated spinosad (LC50 =0.008 mg/L) | 2.8±0.02b | 0.6±0.02c | 0.35±0.02b,c | 48.99 | 79.86 | 72.00 |
Note: Different letters in the same column indicate statistically significant differences according to Student–Newman–Keuls test (P≤0.05). The values indicated by the different letters in the same columns were compared, and that showed significant difference. On the contrary, the values indicated with the same letter in the same column showed that there is no significant difference between them.
Abbreviations: AChE, acetylcholinesterase; CaE, carboxylesterase; GST, glutathione S-transferase; LC50, lethal concentration causing 50% mortality; OD, optical density; SE, standard error.