Eclipse 80i compound

Chiggers were placed between two cover slips on a glass slide, and identification to species was performed using a Nikon Eclipse 80i compound microscope (Nikon Corp., Tokyo, Japan) at 400× or 600× magnification. Images were viewed and saved using the Nikon NIS Elements D 4.13.05 software package. Both autofluorescence and bright-field microscopy techniques were used [38 (link)]. A scale bar was applied to each image. All morphometric measurements and image manipulation were performed using ImageJ (https://imagej.net/ImageJ). The genus was identified with reference to Nadchatram and Dohany’s 1974 key to Southeast Asian chigger genera [39 ]. A wide range of taxonomic identification keys were employed to identify chiggers to species level [40 –44 (link)].

Isolates on PDA plates were incubated at 25 °C for 30 days under near-ultraviolet (UV) light (12 h light/12 h dark). The growth rate of mycelium was measured in five duplicates. Colony color on PDA, Corn meal agar (CMA), and Oatmeal agar (OMA) media incubated at 25 °C near UV light with 12 h, was investigated according to the method of Rayner [84 ]. The morphology imagines were taken using Canon 600D digital camera (Canon Inc., Tokyo, Japan) after 10 days of incubation. Conidiomata and conidia were observed under the OLYMPUS SZX16 stereomicroscope (Olympus Corporation, Tokyo, Japan), conidial length/wide ratio of 30 conidia was measured with a stage micrometer under a Motic BA200 light microscope (Motic China Group Co., Ltd., Nanjing, China). Alpha and beta conidia were measured for calculating means ( $\overline{x}$ ) and standard deviations (SD). The conidia ranges were shown as (min−) $\overline{x}$ − SD − $\overline{x}$ + SD (−max) μm ( $\overline{x}$ ± SD). Conidia digital images were captured using Nikon Eclipse 80i compound light microscope imaging system (Nikon Corporation, Tokyo, Japan).

Fresh leaves and stems were sectioned transversely (80–100 µm) using a Vibratome. Sections were stained, mounted onto glass slides, and viewed using a Nikon Eclipse 80i compound and fluorescent microscope equipped with a Nikon DS-Fi1camera. Images were captured on NIS-Elements D 4.00 software. The following compounds were identified and localized using appropriate histochemical stains.