## 2 Results and Discussion
### Analysis of Picked Flowering Plant VOCs
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{_O. sphegeodes_ subsp. sphegeodes_} & _O. bertolomil_ subsp. _bencassis_ & _N. riderata_ \\ \hline
**Compounds** & **RT \({}^{*}\)** & **Mean (\(n=3\)) \({}^{b}\)** & **SD \({}^{d}\)** & **Mean (\(n=3\))** & **SD** & **Mean (\(n=3\))** & **SD** \\ \hline thujene & 6.41 & 3.05 & 0.97 & 0.18 & 0.00 & 0.20 & 0.00 \\ \(\beta\)-pinene & 9.63 & 1.42 & 0.64 & ND & - & 0.37 & 0.05 \\ abstinence & 10.55 & 0.65 & 0.07 & ND & - & 0.20 & 0.18 \\ \(\beta\)-myrence & 13.33 & 2.07 & 0.09 & ND & - & 0.58 & 0.57 \\ terpene & 14.39 & 2.83 & 0.25 & ND & - & 1.02 & 0.09 \\ d-limonene & 14.69 & 0.99 & 0.13 & ND & - & 2.91 & 1.27 \\ \(\gamma\)-terpinene & 16.40 & 0.46 & 0.00 & ND & - & 0.23 & 0.00 \\ copane & 23.38 & ND & - & 1.93 & 1.56 & ND & - \\ isolongidene & 23.89 & ND & - & 0.46 & 0.08 & 0.22 & 0.03 \\
4-thujanol & 24.58 & 0.51 & 0.08 & 0.27 & 0.00 & 0.12 & 0.03 \\ linalool & 24.71 & ND & - & ND & - & 0.30 & 0.01 \\ quinhydrone & 24.98 & 0.20 & 0.00 & 6.55\({}^{\dagger}\) & 0.04 & 0.17 & 0.08 \\ carcyphillene & 25.61 & 0.07 & 0.02 & 0.18 & 0.07 & 0.08 & 0.27 \\
4-terpineol & 25.79 & 0.29 & 0.01 & 0.87 & 0.00 & 0.12 & 0.02 \\ \(\beta\)-farsene & 27.21 & ND & - & ND & - & ND & - \\ verbenone & 27.64 & 0.24 & 0.03 & ND & - & 0.13 & 0.02 \\ napthalene & 28.90 & ND & - & ND & - & 0.22 & 0.04 \\ sesquiplelandrene & 29.11 & ND & - & ND & - & 0.08 & 0.02 \\ estragol & 30.05 & 0.14 & 0.00 & ND & - & ND & - \\ \hline
**Total** & & **67.57** & & **17.19** & & **13.33** & \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & \multicolumn{2}{c}{_O. sphegodes_ **subsp. sphegodes**} & _O. bertoloni_ **subsp. _banccessis_ & _N. tridentata_ & \\ \hline
**Compounds** & **RT \({}^{*}\)** & **Mean (\(n=3\)) \({}^{*}\)** & **SD \({}^{*}\)** & **Mean (\(n=3\))** & **SD** & **Mean (\(n=3\))** & **SD** \\ \hline \multicolumn{6}{c}{_Free fatty acids_} & & & & \\ acetic acid & 22.27 & 0.24 & 0.07 & 0.07 & 0.03 & ND & - \\ formic acid & 23.46 & ND & - & 0.13 & 0.00 & ND & - \\ propionic acid & 24.27 & ND & - & ND & - & ND & - \\ pivalic acid & 25.21 & 0.04 & 0.00 & ND & - & 0.22 & 0.27 \\ hexanoic acid & 30.34 & 0.36 & 0.11 & 0.09 & 0.02 & 0.11 & 0.01 \\ heptanoic acid & 32.02 & ND & - & 0.14 & 0.05 & 1.34 & 0.18 \\ octanoic acid & 33.06 & 0.06 & 0.02 & 0.16 & 0.02 & ND & - \\ nonanoic acid & 34.13 & 0.19 & 0.05 & 0.31 & 0.01 & 0.14 & 0.06 \\ \hline
**Total** & **0.88** & & **0.91** & & **1.81** & \\ \hline \multicolumn{6}{c}{_Miscellaneous_} & & & & \\ acetonitrile & 5.42 & 2.37 & 1.03 & 0.63 & 0.20 & 0.36 & 0.03 \\ nicotinamide & 28.46 & 0.35 & 0.01 & 0.75 & 0.35 & 0.3 & 0.15 \\ dimethyl sulfone & 31.24 & 0.37 & 0.02 & ND & - & ND & - \\ \hline
**Total** & **3.08** & & **1.37** & & **0.65** & \\ \hline \hline \end{tabular}  
* \({}^{*}\) Retention time; \({}^{*}\) Normalized amount of volatile compounds (percentage) (peak of volatile compound/total peak area of all volatile compounds) of _O. sphegodes_ subsp. _O. bertoloni_ subsp. _banccessis_ and _N. tridentata_ flowering orchid samples (\(n=3\)); \({}^{*}\) Standard deviation (\(\pm\)); ND: not detected; The most representative compounds for all orchids species were labeled with a number.  
\end{table} 
Table 2: _Cont._  
**Figure 2.** Volatile fingerprint of _O. sphegodes_ subsp. _sphegodes_ **(A)**, _O. bertolonii_ subsp. _benacensis_ **(B)** and _N. tridentata_ **(C)** picked flowering plants (the most representative compound peaks were labeled with numbers).