Al104 analytical balance

During dissection, cicadas were first weighed on a scale (AL104 Analytical Balance, Mettler Toledo; resolution, 0.1 mg), and full-body weights were collected. Each of their wings (left/right forewings and hindwings) were then carefully removed by cutting with scissors (Fine Science Tools, spring scissors) and individually weighed. The left forewing was removed first and weighed, followed by the left hindwing, right forewing, and right hindwing. After dissection, cicadas were quickly wrapped in facial tissues (Kleenex), labeled, and placed back in the freezer. Wrapping cicadas in tissue allowed us to anesthetize them rapidly, limit hemolymph bleeding, damage that the cicada might do to itself, and allowed us to quickly label the cicada (at this point, cicadas could still crawl away unless gently restrained). Wings were arranged on black cardstock and photographed using a DSLR camera (Nikon D850) and macro lens (Sigma 180 mm), using a micro SD card (length, 14.99 mm) as a scale bar. Imaging was illuminated with LED lighting, which was chosen because it does not locally heat the air (or wings).

A high performance liquid chromatography system (Shimadzu, Japan) equipped with Agilent Zorbax XDB-C18 (250 mm × 4.6 mm, 5.0 μm) column and UV detector was applied in homogeneity test, stability study, and measurement of main component and unknown organic impurities. The Karl Fischer titration (METTLER TOLEDO DL39) was used for measurement of water content in chloramphenicol raw material. The analysis of nonvolatile impurities and volatile organic impurities was carried out on Thermal Gravity Analysis (PerkinElmer Pyris1, US) and gas chromatography coupled with flame ionization detector (GC-FID), respectively. A Bruker Avance III spectrometer with a cryoprobe at 400 MHz was employed to measure the mass fraction of chloramphenicol. All samples were weighed by using a Mettler AL104 analytical balance with a metrological verification certificate. Qualitative analysis was performed on a Bruker VERTEX 70 Infrared spectroscopy and Agilent mass spectrometry, respectively.

In January 2015, fallen leaves of the four selected species were collected from the forest floor and air‐dried for one month. In August 2015, 5 g of air‐dried litter of each species was placed into litterbags with 2‐mm mesh size. Three litterbags per species were laid under each of the selected trees, for a total of 480 litterbags (4 species × 3 litterbags × 40 trees). The initial mass of litter for each species was calculated using three randomly chosen bags for each species, which were oven‐dried for 24 h at 80°C, and then weighed (Aponte et al., 2012). These mass data were later used in the analysis as initial litter mass per species. In August 2017, all litterbags were retrieved, and non‐litter material including soil and insects was carefully removed. The remaining litter was then oven‐dried at 80°C for 24 h and weighed again with a precision of 0.0001 g (AL104 Analytical Balance; Mettler‐Toledo Instruments, Shanghai, China).