Variability and plasticity in life-history traits enhance an organism’s ability to cope with heterogeneous environmental conditions. We investigated the seasonal life cycle of the snail-feeding ground beetle Carabus (Damaster) blaptoides in a lowland riverine habitat in western Honshu, Japan, over a two-year period (2014–2015). Carabus blaptoides exhibited different seasonal activity patterns between the two years, with the duration of female reproductive activity ranging from spring to late summer or autumn, the occurrence of larvae from June to November or from May to August, and the occurrence of newly emerged adults from July to October or from June to August. Autumn larvae appeared to overwinter, which was confirmed by a field rearing experiment. The body size of adult female C. blaptoides showed substantial variation. Although egg number was unrelated to body size, larger females had larger maturing eggs, implying that they produce larger larvae with greater foraging ability. In combination with previous observations of the seasonal cycles of C. blaptoides in mountain habitats, our results indicate that C. blaptoides exhibits altitudinal variation in its seasonal life cycle: from an extended period of reproduction and larval development mostly within a year (with occasional larval overwintering) at lower altitudes, to a short midsummer reproductive period without the appearance of newly emerged adults at higher altitudes. Our study suggests that C. blaptoides possesses considerable plasticity in its seasonal life cycle and reproductive traits.

日本産シマカラスヨトウ種群に属するシマカラスヨトウ，オオシマカラスヨトウ，ナンカイカラスヨトウの幼虫はいずれも広食性で，複数種が同時期・同所的に発生する．さらに，外見が類似していることから同定は困難であり，寄主植物や農業被害の混同が指摘されている．そのような状況の中，ニセシマカラスヨトウが日本から新たに記録されたことで，日本産本種群の幼虫期における識別も新たに検討する必要が生じた．そこで著者らは，野外調査によって本種群の幼虫を採集するとともに寄主情報を収集し，終齢幼虫における識別点，終齢と他齢期の判別方法，および寄主植物を検討した．その結果，主に気門線，胸脚の斑紋，脚基部と脚底部の色彩によって4種の終齢幼虫を識別できることが分かった．また，前額最大幅，頭部の斑紋，脚底部の幅によって終齢とその他の齢期を判別できることも判明した．寄主植物に関しては，4種とも広食性を示し寄主範囲は互いに重複していることが分かった．特にサクラ類（バラ科）やアジサイ類（アジサイ科）では，同一株や隣接する株から最多で3種が同時に採集されたことから，4種は幼虫期に明確な食い分けを行っていないと考えられた．

幼虫の研究は，その種を知る上で非常に重要であるが，コウチュウ目オサムシ科の幼虫期および幼虫の形態と生態に関しては，不明な点が多い．セアカヒラタゴミムシは，身近な種で飛翔する個体が存在することがわかっているが，幼虫については，幼虫の時期とその期間，種同定に必要な情報および生態など基礎的な知見が少ない．そこで，1）幼虫の種同定にDNAバーコーディングを活用して本種の幼虫期を明らかにし，2）幼虫の行動と形態的特徴を記録することで野外における幼虫の生態を形態的特徴とリンクさせた．

まず，本種の幼虫期を把握するために，野外調査を実施し本種の幼虫を捕獲した．その結果，本調査地では，幼虫が捕獲されたのは10月～4月で，各齢の捕獲数から，齢が上がるとともに活動性が高まると考えられた．また12～2月にも幼虫が捕獲されたことから，この時期も餌生物を探して活発に行動していると思われた．幼虫越冬であることはこれまでも知られていたが，3齢幼虫で越冬し，さらに幼虫期間が6ヶ月と非常に長いことがはじめて明らかにされた．

次に，幼虫の形態を調べ，生態との関連を考察した．頭部は，大あごの付け根の太さが頭部に比べ細長く，湾曲し先端部は鋭かった．大あごで噛みついてくるなど，形態だけでなくその攻撃性からも肉食の捕食者であることが示唆された．胸部の腹面のみは，光沢がなく柔らかく，これは脚を自在に動かすためにそのようになっていると考えられた．腹部は，尾状突起が長く，このことから地表走行タイプと推定できた．また，柔らかい円筒状の第10腹節があり，これを吸盤のように使って自在に急停止したり，方向転換を行ったりすることで，胸部の脚の歩行機能を補完している可能性が示唆された．

オサムシ科においては幼虫の研究が少なく，特に生態に関するものはほとんどない．しかし，本研究のように形態と関連づけることで生態を読み解くことは可能であり，両者を関連づけることで互いの研究を補完できると考えられる．

This study provides the first documented evidence of Miscanthus sinensis serving as a host plant for Sesamia turpis (Butler, 1879). Field surveys were conducted between June and July 2024 in semi-natural grassland in Ibaraki Prefecture, Honshu, Japan. Twelve larvae of S. turpis were collected from the culms of M. sinensis with feeding traces and frass on the leaf sheaths. They fed on fresh M. sinensis culms under laboratory conditions, and four individuals pupated and emerged as adults.

The eucalyptus shoot psyllid, Blastopsylla occidentalis Taylor, is reported in Japan for the first time. The distribution of this species, which is native to Australia, has spread globally and is known to cause significant damage to eucalyptus trees. The species has currently been found on Eucalyptus globulus trees in parks in the Kinki region of western Japan. Although substantial damage has not yet been observed in these groves, it is important to raise awareness of the potential for this species to spread and cause harm to eucalyptus trees.

An unidentified species of Phaenoserphus (Proctotrupidae) emerged from a larva of Carabus (Acoptolabrus) gehinii collected in Hokkaido, Japan. In the laboratory, the biology of this proctotrupid, development, courtship behavior, and parasitization to C. (Damaster) blaptoides, were observed. The host acceptance of the Phaenoserphus sp. was briefly tested.

The yellow-legged hornet, Vespa velutina, is native to parts of Asia, and has recently spread as an invasive species to Korea, France, and other regions of Europe. In Japan, V. velutina workers were first detected on Tsushima Island in 2013, and genetic analyses confirmed that these invasive populations originated from the subspecies V. v. nigrithorax. Although V. velutina has been captured in more than eight regions across Japan, naturalization has so far been confirmed only on Tsushima Island. Here, we examined V. velutina specimens collected in Fukuoka and Hisayama, Fukuoka Prefecture, in 2022 to trace invasion pathways. Morphological identification verified their worker caste, and mitochondrial DNA analysis identified them as V. v. nigrithorax of the H1 haplotype, which occurs in both Korean and Japanese populations but is distinct from the European H6 haplotype. Phylogenetic analysis based on 13 protein-coding mitochondrial genes suggested that the Fukuoka and Hisayama populations may represent a distinct invasion event from other Japanese populations.

A melanistic female of Corymica pryeri (Butler, 1878) was collected on Hachijojima Island, Tokyo, Japan, on May 23, 2025. The specimen exhibited aberrant dark brown wing coloration compared with the typical yellow ground color. The species identity was confirmed by DNA barcoding of the mitochondrial COI region. This represents the first documented record of a melanistic variant of C. pryeri, although similar variations have been recorded in the congeneric C. deducta.