Tridecane

Heptane (99%), nonane (99%), undecane (≥99%), dodecane (99%), tridecane (≥99%), tetradecane (≥99%), pentadecane (≥99%), hexadecane, heptadecane (99%), octadecane (99%), nonadecane (99%), eicosane (99%), heneicosane (≥99.5%), docosane (99%), tricosane (99%), tetracosane (99%), pentacosane (99%), hexacosane (99%), octacosane (99%), and triacontane (99%) were purchased from Sigma-Aldrich (Darmstadt, Germany). Octane (98%) and decane (≥99%) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Acetone and hexane were of HPLC grade and purchased from Elite Advanced Materials Sdn. Bhd. (Selangor, Malaysia). Ultrapure water (18.2 MΩ cm⁻¹) was purified by a Millipore Milli-Q system (Bedford, MA, USA).

Hexadecyltrimethylammonium chloride (≥98%, CTAC), tetraethyl orthosilicate (98%, TEOS), 1,6-diisocyanatohexane (≥99.0%), tridecane (≥99%), ammonium hydroxide solution (28 wt%, NH₃·H₂O), ammonium fluoride (≥98%, NH₄F), 3- aminopropyltriethoxysilane (99%, APS), formaldehyde (37 wt% in water), sodium cyanoborohydride (NaBH₃CN), sodium cyanoborodeuteride (NaBD₃CN), trypsin (from bovine pancreas), protease inhibitor cocktail, formic acid (FA), urea, trifluoroacetic acid (TFA), dithiothreitol (DTT), iodoacetamide (IAA), and ammonium acetate were purchased from Sigma-Aldrich (St. Louis, MO, USA). Phosphatase inhibitor cocktail was ordered from Thermo Fisher Scientific (Rockford, USA). ¹³C-D₂-formaldehyde was purchased from Cambridge Isotope Laboratories, Inc. (Andover, USA). Dry pyridine was provided by Aladdin (99.8%, Shanghai, China). Toluene and chloroform (≥99.0%) were bought from Kaixin (Tianjin, China), and toluene was purified by refluxing (110 °C) over sodium and distilling (136 °C). Acetone (≥99.5%) and ethanol (≥99.8%) were obtained from Kermel (Tianjin, China). Acetonitrile (≥99.9%, ACN) was purchased from Merck (Darmstadt, Germany). Deionized water was used throughout the experiments (Millipore, Milford, MA, USA). Other reagents were all analytical grade. All the standard non-phosphorylated peptides were purchased from ChinaPeptides (Shanghai, China).

Authentic standards of (R)-(+) α-pinene (purity 99%), 2-methoxy-3-(1-methylpropyl)-pyrazine (purity 99%), thymol (99%), and tridecane (purity 99%) were purchased from Sigma Aldrich, St. Louis, MO, USA. Methyl salicylate (purity 97%) and (R)-(+)-limonene (purity 97%) were purchased from Sigma Aldrich, Steinhelm, Germany.

Quantitative calibration standards of 2, 10, 20, 100, and 200 ng/μl were made from (E)-2-octenal, (E)-2-decenal, and tridecane (all >94%, Sigma-Aldrich, Australia) diluted using dichloromethane. All calibration standards also contained tetralin (IS) added from a 10 μg/μl stock. (E)-2-octenal, (E)-2-decenal, and tridecane quantities from H. halys headspace samples were calculated using calibration linear equations. 4-Oxo-(E)-2-hexenal was prepared from 2-ethylfuran following Moreira and Millar [18 (link)]. To determine whether differences in defensive compound quantity between diapausing and diapause-disrupted H. halys were significant, non-parametric Mann-Whitney U two-tailed tests were performed, following Shapiro-Wilk tests for normality.

The acaricides coumaphos, amitraz, flumethrin and tau-fluvalinate and the internal standards (arachidic acid methyl and tridecane) were obtained from Sigma-Aldrich, Saint Louis, MO, USA; and HPLC-grade solvents from Machery-Nagel, Bethlehem, PA, USA or LiChrosolv were used. Concentrations were chosen based on previous data reporting the presence of these pesticides in pollen and honey. Tau-fluvalinate was detected at a concentration of 750 ppb in honey [27 (link)] and of 487.2 ppb in pollen [28 (link)]: the selected dose was approximately the average between those values (666 ppb). In the case of coumaphos, 2020 ppb were found in honey [29 (link)] and 5800 ppb in pollen [30 (link)], so the selected dose was approximately the average (3333 ppb). The maximum detection in honey for amitraz was 555 ppb and for flumethrin was 1 ppb [31 (link)].