Ants play an important role in forest ecosystems in terms of biomass and various biological interactions, but non-destructive continuous observation of colonies is difficult for species nesting in trees. During the investigations of forest arboreal small mammals using wood nest boxes between January and December 2021, nestings of Camponotus kiusiuensis Santschi were observed at high frequencies in a census site on Mount Kyougatake, Saga Prefecture, Kyushu, Japan. We surveyed the nesting site preference of C. kiusiuensis and conducted monthly observations of colony compositions from spring to winter. Among three types of nest boxes, small (500 cm3), medium (1,000 cm3), and large (2,000 cm3), C. kiusiuensis nested in the large nest boxes at significantly higher frequencies. Although the nest boxes were either set at low (1.5–2.0 m high) or high (3.5–4.0 m high) positions of trees, no significant differences were detected in the nesting sites between them. The number of colonies was the highest in April and it gradually decreased from spring to autumn. In the nest boxes in which colonies of C. kiusiuensis were continuously observed until autumn, the developmental stages of immature individuals inside were almost uniform: larvae were observed from April to June, pupae in July, and many adults including males and new alate queens were found in August and September. No or very few ant individuals were observed in October and November, suggesting that workers moved the larvae to other places in late autumn. Based on our observations, the arboreal nest boxes seem not to be suitable sites for overwintering.
Chrysaster ostensackenella (Fitch, 1859), a New World leaf-mining moth, was recorded from Hokkaido, representing the first report of its invasion in Japan. Larvae of C. ostensackenella feed on Robinia pseudoacacia L. and form blotch mines on the upper side of its leaflets. Comparisons of COI barcode markers show that the sequence obtained from the Japanese samples matched with those obtained from Virginia, USA with >98％ identity. This strongly suggests that this species is invasive Japan. Diagnostic morphological information of this species is provided.
Helophorus auriculatus Sharp, 1884 is an endangered water beetle that inhabits earth ditches and small pools in riverbeds and paddy fields. In Japan, the recent record of H. auriculatus has been limited to the Ibaraki Prefecture in 2019 and Tsushima Island, Nagasaki Prefecture in 2020. We rediscovered this species in the Saitama Prefecture, Japan, after 34 years and compared the habitat and adult morphology of this species among different Japanese regions.
We report that a nest of mud-dauber wasp, Sceliphron sp., was found in the Yagibara Shell Mound of Jomon cultural age in Chiba Prefecture, Honshu, Japan. This is the first record to be found nest of Aculeata from shell mounds. Though all Sceliphron species recorded from Honshu, Japan have been considered to be invasive insects, at least one species is considered to be native.
As part of promoting digital transformation (DX) in the field of entomology, we present a method for drawing morphological illustrations of insects using digital devices. The method presented here uses an iPad, Apple pencil, and ibis Paint. The combination of the iPad and Apple pencil is superior in imitating the sensation of drawing with a pen on paper, and the use of the ibis Paint is advantageous in almost all the functions required to create scientific illustrations.
For figures used in scientific papers, the recommended canvas size of the ibis Paint is 2400×3200 pixels with a resolution of 600 dpi. The following steps are recommended for the ibis Paint: first, in the “Settings” set “Use Pressure Sensitivity” and “Palm Rejection” to on, “Quick Eyedropper” to off, and “Stabilizer” to the maximum value of 10 for ease of use. Next, set the following five brushes to Custom Brush: Pencil #1, Dip Pen (Hard), Dashed Line, Outline (Fade), and Felt Tip Pen (Soft).
The layer function is utilized in the drawing process. The drafting procedure differs depending on whether the tracing or grid method is used. In the tracing method, the photograph to be traced is imported and set on the bottom layer. After adjusting the position, angle, and transparency of the photo, create a new layer for the draft and use “Pencil #1” to write the draft. For the grid method, start “Filter” mode and use the filter “Table (Size)” to create a grid. After placing the grid layer on the bottom layer, create a new layer for drafting and write a draft using “Pencil #1”.
For inking (final drawing), use “Dip Pen (Hard)” to draw the outline first, and then add details in sequence. Use “Dashed Line” for structures hidden behind, “Outline (Fade)” for soft hairs, and “Felt Tip Pen (Soft)” for dots. Using different layers for different purposes, such as shadows, three-dimensional expressions, and hairs, makes revising later easier. Screen tones can be used to fill in arbitrary areas with slash or cross lines.
The method presented here can easily applied to simulate traditional drawing techniques.Thus, it can be adopted by different users, from senior researchers who already have established techniques to students who intend to learn scientific drawing. However, this method is still in its infancy, and it is necessary to continue to develop improved methods. Therefore, sharing the practical usage of digital devices with the entire entomological community is also essential.