## 4 Discussion  
The baseline (control-based) metabolic energy substrate analyses indicate that lipids are the main substrates used by _E. heros_, aligning with previous studies on another Hemipteran, _Notoneta glauc_ (Hemiptera: Notonectidae) [30]. The differences between metabolic levels are mainly related to dispersion patterns and physiological responses dependent on energy substrates. Extensive flight intervals, as observed in migratory insects, correlate with a lipid-dependent metabolism [31], while those with sporadic or short-flight dispersal patterns exhibit a preference for carbohydrates [32] or even certain amino acids, such as proline, as observed in some Coleoptera [33]. Meanwhile, insects with mixed \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Element Concentration (mg L\({}^{-1}\pm\) SE)**} & \multicolumn{2}{c}{**Untreated Control**} & \multicolumn{2}{c}{**Pyriproxyfen LC\({}_{30}\)**} \\  & **Pure Distilled Water (H\({}_{2}\)O)** & \multicolumn{2}{c}{**0.688 mL a. i. L\({}^{-1}\)**} \\ \cline{2-5}  & **Females** & **Males** & **Females** & **Males** \\ \hline Copper (Cu) & 0.75 \(\pm\) 0.01 a & 0.77 \(\pm\) 0.02 a & 0.63 \(\pm\) 0.01 a & 1.30 \(\pm\) 0.03 b \\ Nickel (Ni) & 0.59 \(\pm\) 0.48 b & 1.07 \(\pm\) 0.04 d & 0.31 \(\pm\) 0.02 a & 0.64 \(\pm\) 0.02 c \\ Zinc (Zn) & 4.32 \(\pm\) 0.03 d & 3.56 \(\pm\) 0.05 c & 2.94 \(\pm\) 0.08 a & 3.40 \(\pm\) 0.02 b \\ \hline \hline \end{tabular}  
* Means followed by the same letter in a row did not differ significantly from each other, [PERSON]’s test, \(p\leq\) 0.05. a. i. = active ingredient. Internal standard = gallium (Ga) + deionized H\({}_{2}\)O = 10 ug mL\({}^{-1}\) = 10 ppm. n = 32 (eight adults per sex per treatment).  
\end{table} 
Table 1: Mean concentration levels of three major micro-elements in the hemolymph of adult _Euschistus heros_ treated with sublethal pyriproxyfen (LC\({}_{30}\)) in the late nymphal stage (4 th instar). Figure 1: Baseline (untreated control) and post-exposure circulating metabolic fuels in the hemolymph of sublethal (LC\({}_{30}\)) pyriproxyfen-treated adult _Euschistus heros_. (**a**) The concentration of material positive for phospho-sulfonyl-vanillin reagent (=lipids) in females; (**b**) the concentration of lipids in males; (**c**) the concentration of material positive for anthrone reagent (=carbohydrates) in females; (**d**) the concentration of carbohydrates in males. Bars represent standard errors. Significant difference levels determined by Student’s \(t\)-test (ns = non-significant; * = significant at \(p<\) 0.05), n = 256.  
dispersal patterns, i.e., long and short flights, such as Heliothinae pest moths (Lepidoptera: Nocutiidae), use lipids and carbohydrates equally [34; 35]. A noticeable variation in _E. heros_ energetic metabolites after exposure to pyriproxyfen was observed, particularly for carbohydrate levels, despite them being half of the lipid levels. The circulating carbohydrate concentration is also a reflection of the breakdown of glycogen in the fat body, which can occur in high-lipid-demand situations [36; 37]. However, glycogen levels tend to be low relative to lipid reserves in some Heteroptera, subject to dietary and dispersion variations. Most phytophagous stalk bugs (Hemiptera: Pentatomidae) have diverse patterns of dispersion: _Diccareus melananthus_ is a fast- and frequent-flight insect, especially in the cooler periods of the day [38]; _Nezara viridula_ and _Piezadorus guildini_ can disperse up to 70 m in high-temperature (>30 \({}^{\circ}\)C) conditions, while _E. heros_ is the species with the lowest flight capacity [39]. Therefore, this variation among phytophagous stalk bug dispersal behavior could explain the higher lipid dependency of _E. heros_ and, consequently, the higher and more stable lipid levels in the hemolymph. In addition to flight and other dispersal strategies, other physiological mechanisms, such as reproduction and diapause, have high energy demands depending on the insect species [40; 41; 42].