D7100

To collect fruit flies, we used sets of three traps made of modified urine sample cups (described in Leblanc et al. 2015a ), separately baited with the fruit fly lures methyl eugenol, cue-lure and zingerone, with a 10×10mm piece of dichlorvos insecticide strip to kill trapped flies. These traps were maintained for three to five days at each of 220 sites in forest reserves and national parks in 2015 and 2017 (Figure 1). Specimens retrieved from the traps were preserved in 95 % ethanol and stored in a -20 °C freezer when returned to the laboratory. A selection of specimens was dried and pinned. We pinned these specimens fresh out of the ethanol each with a minuten pin through the scutum, then soaked them in ethyl-ether for 3–12 hours to preserve the coloration, and double-mounted them. We photographed specimens using a Nikon D7100 camera attached to an Olympus SZX10 microscope. Pictures from different focal plains were merged using Helicon Focus pro v6.7.1. Initially, we performed identifications based on morphology, using available keys (Drew and Hancock 1994 (link), Drew and Romig 2016 ). Measurements were taken using an ocular grid mounted on an Olympus SZ30 dissecting microscope. The collecting and taxonomy information for all specimens can be found at BOLD http://dx.doi.org/10.5883/DS-VIETDACI.

One fossil specimen was collected from the fossiliferous bed in Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia Autonomous Region of China, which is near the border of Liaoning Province and Inner Mongolia (Figure 6). The fossil specimen was a compression with coalified residues embedded in tuffaceous siltstone. The Daohugou Formation contained a Mid-Jurassic flora [54 ]. Many fossils of plants and animals were found in this fossil bed [52 (link),54 ,59 (link)]. The absolute age of this fossiliferous bed was dated back to the Mid-Jurassic (~164 myr, Callovian) based on Ar40/Ar39 and SHRIMP U-Pb dating methods [52 (link),54 ,60 ,61 (link)]. This new fossil was studied using a light microscope and digital cameras (Nikon D850, D7100, Olympus TG4 and Sony A7M3). The fossil specimen is deposited in the Herbarium (NF), Nanjing Forestry University, Nanjing, Jiangsu Province of China.