## 3 Results
### Oryazephilus surinamensis  
This species showed the greatest variability in mortality rates among DE formulations (Table 6). Exposure for 7 d was enough to control all adults (100%) in wheat treated with 1000 ppm of DE5 or DE6. On the contrary, mortality of the same intervals ranged from 1.1 to 2.7% in the case of DE1, DE2 or DE3. With longer exposure periods, the mortality continued to rise gradually, for all DE and doses. After 21 d of exposure on wheat treated with DE6 at 500 ppm, adult mortality was complete (100%).  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{1}{c}{**Dose**} & **200 ppm** & **500 ppm** & **1000 ppm** \\ \hline
21 d & DE1 & \(1.1\pm 1.1\) Cb & \(2.2\pm 1.2\) Bab & \(6.1\pm 2.0\) Ba \\  & DE2 & \(2.2\pm 1.6\) Cb & \(6.6\pm 2.0\) Bab & \(8.8\pm 2.6\) Ba \\  & DE3 & \(3.3\pm 1.1\) Cb & \(2.2\pm 1.4\) Bb & \(7.7\pm 2.5\) Ba \\  & DE5 & \(40.5\pm 5.0\) Bc & \(70.5\pm 5.9\) Ab & \(88.3\pm 2.7\) Aa \\  & DE6 & \(54.4\pm 4.5\) Ac & \(72.7\pm 4.4\) Ab & \(92.2\pm 3.4\) Aa \\ \hline \hline \end{tabular} \({}^{*}\) For ANOVA parameters between doses in the same DE formulation, in all cases df = 14,120. For 7 d: F = 44.0, \(p<0.01\); for 14 d: F = 63.7, \(p<0.01\); 21 d: F = 122.7, \(p<0.01\). For ANOVA parameters between DE in the same Dose and Day, in all cases df = 4,40. At 200 ppm: for 7 d: F = 8.2, \(p<0.01\); for 14 d: F = 8.2, \(p<0.01\); for 14 d: F = 19.0, \(p<0.01\); 21 d: F = 60.7, \(p<0.01\). At 500 ppm: for 7 d: F = 28.7, \(p<0.01\); for 14 d: F = 44.2, \(p<0.01\); 21 d: F = 111.4, \(p<0.01\). At 1000 ppm: for 7 d: F = 51.2, \(p<0.01\); for 14 d: F = 120.7, \(p<0.01\); 21 d: F = 280.1, \(p<0.01\).  
\end{table}
Table 4: _Cont._  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{1}{c}{**Dose**} & **200 ppm** & **500 ppm** & **1000 ppm** \\ \hline
7 d & DE1 & \(3.3\pm 1.1\) ABa & \(4.3\pm 1.4\) ABa & \(6.6\pm 2.7\) Ba \\  & DE2 & \(2.2\pm 0.8\) ABa & \(7.7\pm 1.4\) Aa & \(7.7\pm 2.2\) Ba \\  & DE3 & \(5.0\pm 1.6\) Aa & \(2.2\pm 0.8\) Ba & \(6.6\pm 2.0\) Ba \\  & DE5 & \(3.3\pm 1.8\) ABa & \(4.4\pm 1.3\) ABa & \(6.6\pm 0.8\) Ba \\  & DE6 & \(0.0\pm 0.0\) Bb & \(5.5\pm 2.1\) ABb & \(33.3\pm 5.8\) Aa \\ \hline
14 d & DE1 & \(5.0\pm 2.2\) ABa & \(7.5\pm 2.5\) BCa & \(12.2\pm 2.9\) Ba \\  & DE2 & \(3.8\pm 1.1\) ABb & \(13.3\pm 2.2\) ABa & \(15.0\pm 3.1\) Ba \\  & DE3 & \(6.6\pm 2.2\) ABa & \(6.6\pm 1.6\) Ca & \(9.4\pm 2.5\) Ba \\  & DE5 & \(8.3\pm 2.2\) Aa & \(9.4\pm 1.7\) BCa & \(12.7\pm 2.2\) Ba \\  & DE6 & \(2.7\pm 1.2\) Bc & \(16.6\pm 3.2\) Ab & \(49.4\pm 7.4\) Aa \\ \hline
21 d & DE1 & \(8.3\pm 2.3\) Bb & \(16.8\pm 4.7\) Bab & \(21.1\pm 3.8\) Ba \\  & DE2 & \(8.3\pm 1.1\) Bb & \(17.2\pm 3.0\) Ba & \(20.0\pm 2.5\) Ba \\  & DE3 & \(11.1\pm 1.8\) ABb & \(11.1\pm 2.0\) Bb & \(17.2\pm 1.8\) Ba \\  & DE5 & \(15.0\pm 2.6\) Aa & \(15.0\pm 2.6\) Ba & \(18.8\pm 2.8\) Ba \\  & DE6 & \(9.4\pm 2.6\) Abc & \(30.5\pm 4.4\) Ab & \(62.2\pm 7.2\) Aa \\ \hline \hline \end{tabular} \({}^{*}\) For ANOVA parameters between doses in the same DE formulation, in all cases df = 14,120. For 7 d: F = 12.4, \(p<0.01\); for 14 d: F = 14.3, \(p<0.01\); 21 d: F = 15.8, \(p<0.01\). For ANOVA parameters between DE in the same Dose and Day, in all cases df = 4,40. At 200 ppm: for 7 d: F = 2.0, \(p=0.11\); for 14 d: F = 1.4, \(p=0.24\); 21 d: F =15., \(p=0.19\). At 500 ppm: for 7 d: F = 18.8, \(p=0.14\); for 14 d: F = 3.2, \(p=0.02\); 21 d: F = 4.6, \(p<0.01\). At 1000 ppm: for 7 d: F = 13.3, \(p<0.01\); 21 d: F = 21.5, \(p<0.01\).  
\end{table}
Table 5: Mean (% \(\pm\) SE) mortality of _R. dominica_ adults after exposure for 7, 14 and 21 d on wheat treated with DE at three doses (means within each row followed by the same uppercase letter are not significantly different; means within each column for the same exposure followed by the same lowercase letter are not significantly different; HSD test at 0.05) \({}^{*}\).