## 2 Results and Discussion
### OC Kappa Induced an Increase in Total Essential Oils and a Reprogramming of Terpenoid Metabolism  
The level of total essential oils in leaves of control _Eucalyptus_ trees was 4.5 mg\(\cdot\)g\({}^{-1}\) of FT and in trees treated with OC kappa it was 5.5 mg\(\cdot\)g\({}^{-1}\) of FT, which corresponds to an increase of 22% at four months after treatment at 4 months after treatment. In addition, the level of six terpenoids decreased in _Eucalyptus_ trees treated with OC kappa (Table 1). The monoterpenoids from limonene family, eucalyptpol, sabinene and \(\alpha\)-terpineol, decreased in treated _Eucalyptus_ trees from 3757 to 3485, 101 to 42 and 499 to 457 g\(\cdot\)g\({}^{-1}\) of FT, respectively, and the monoterenoid of pinene family, \(\alpha\)-pinene, decreased from 499 to 457 g\(\cdot\)g\({}^{-1}\) of FT. Moreover, the level of the sesquiterpenoid of cadinene family, \(\delta\)-cadinene, decreased from 29 to 14 g\(\cdot\)g\({}^{-1}\) of FT and that of isolatedene family, isoledene decreased from 26 to 11 g\(\cdot\)g\({}^{-1}\) of FT (Table 1). Regarding the increase in total essential oils in _Eucalyptus_ trees treated with OC kappa, we have previously determined that treated trees cultivated in the field for three years showed an increase in essential oils of 72% compared to controls [19]. This indicates that the effect of OC kappa persists after three years and that the level of total essential oils increased with time in treated _Eucalyptus_ trees. Regarding terpenoids that decreased in treated _Eucalyptus_ trees such as eucalyptpol, sabinene, \(\alpha\)-terpineol, \(\alpha\)-pinene, \(\delta\)-cadinene and isoledene they are probably the precursors that are consumed to synthesize terpenoids that increased or that were synthesized _de novo_ in treated trees. On the other hand, the level of 12 terpenoids increased in the leaves of treated _Eucalyptus_ trees (Table 2). Monoterpenoids from the limonene family, silvestrene, \(\alpha\)-phellandrene, \(\gamma\)-terpinene and limonene oxide, increased from 142 to 419, 9 to 27, 9 to 22 and 7 to 12 g\(\cdot\)g\({}^{-1}\) of FT, respectively, and that of monoterenoid of the pinene family, \(\beta\)-pinene, increased from 28 to 66 g\(\cdot\)g\({}^{-1}\) of FT. The sequiterpenoid of the cadinene family, \(\gamma\)-cadinene, increased from 4 to 5 g\(\cdot\)g\({}^{-1}\) of FT and those of the isoledene family, aromadendrene, viriflorene, \(\alpha\)-gurjunene, \(\gamma\)-gurjunene and \(\alpha\)-guaiene increased from 180 to 267, 39 to 82, 33 to 208, 16 to 78 and 1 to 6 g\(\cdot\)g\({}^{-1}\) of FT, respectively. In addition, the linear monoterpene myrcene increased from 42 to 53 g\(\cdot\)g\({}^{-1}\) of FT in treated trees (Table 2). \begin{table}
\begin{tabular}{c c c c} \hline \multirow{2}{*}{**Compound**} & **Level in Control Trees** & **Level in Treated Trees** & \multirow{2}{*}{**\% of Decrease**} \\  & **(\(\mu\)g\(\cdot\)g\({}^{-1}\) FT)** & **(\(\mu\)g\(\cdot\)g\({}^{-1}\) FT)** & \\ \hline Eucalyptpol & 3757 \(\pm\) 188 & 3485 \(\pm\) 174 & 7.2 \\ Sabinene & 101 \(\pm\) 8.1 & 42 \(\pm\) 3.3 & 59 \\ \(\alpha\)-Terpineol & 45 \(\pm\) 3.6 & 39 \(\pm\) 3.1 & 13 \\ \(\alpha\)-Pinene & 499 \(\pm\) 25 & 457 \(\pm\) 23 & 8 \\ \(\delta\)-Cadinene & 29 \(\pm\) 2.3 & 14 \(\pm\) 1.1 & 52 \\ Isoledene & 26 \(\pm\) 2.1 & 11 \(\pm\) 0.9 & 59 \\ \hline \end{tabular}
\end{table} 
Table 1: Levels of the main terpenoids in leaves of control _Eucalyptus_ and in trees treated with OC kappa. Regarding terpenoids that increased in response to OC kappa, it is important to mention that the monoterpene \(\gamma\)-terpinene showed insecticidal activity _in vitro_ against the red flour beetle _Tribolium castaneaun_ (Coleoptera) [22]. In addition, the monoterpene \(\beta\)-pinene displayed insecticidal activity against the rice weevil _Sitophilus oryzaea_ (Coleoptera) [23]. Moreover, the sequiterpene aromadendrene has antibacterial activity and showed a synergistic effect with eucalypt [13, 14].