We examined the flight period and flight muscles of Dolichus halensis. Flying individuals were captured by a find-and-capture method under fluorescent lights on the stairs of an apartment in Chiba Prefecture, and walking individuals were captured by pitfall traps on the same premises. We conducted sampling daily throughout the year from 2021 to 2024. We investigated all individuals for flight muscles, hind wings, body length, and sexual maturity.

Regarding flight muscles in all flying individuals, the metathorax was filled with flight muscles. We found that some flying individuals had robust flight muscles with continuous muscle fibers, while others had fragile flight muscles with fragmented muscle fibers. In all walking individuals, no flight muscles were observed. As for body length, flying individuals were significantly larger than walking individuals for both sexes. Although the hind wings were well developed macropterous, with the same shape and color in all individuals, flying individuals had more wing damage, which may reflect their frequent use. All individuals began to mature from the end of August to September.

This study suggested that some individuals of this species develop flight muscles while others do not. Furthermore, our results indicated that even developed flight muscles histolyse later in their life cycle, supporting the idea that this species retains flight muscle polymorphism. Flight may occur mainly when sexual maturity begins, but sometimes also occur during the immature period. By continuing this survey, it will be possible to see the impact of global warming on the flight period.

New hosts of the following Sarcophaga species are recorded from Japan: Sarcophaga gravelyi Senior-White, S. schuetzei Kramer, and S. uliginosa Kramer. The first two species were collected from adult cicadas, Tanna japonensis Distant, while the last emerged from a lepidopteran pupa of Ivela auripes (Butler) (Lymantriidae).

An example of pronounced venational anomalies is described in a specimen of Inocellia japonica Okamoto, 1917 from Japan.