Hidemori YAZAKI’s Nature Diary

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[hidemoriyazaki]

A species of Reticulated beetle, Tenomerga sp., caught in the light trap. This group is considered to have retained a primitive form even amongst beetles, and is said to have changed little in appearance since the fossils dating back some 200 million years. The texture of the elytra, with their exquisite seal-carving-like pattern reminiscent of Nanbu ironware, is truly magnificent.

ライトトラップにやってきた、ナガヒラタムシの仲間。 甲虫の中でも原始的な形態をとどめたグループで、約2億年前の化石から姿があまり変わっていない、とされる。 南部鉄器のような上質な翅の篆刻の質感が見事。

Nagano Pref. 長野県 2025-07-25

[hidemoriyazaki]

One morning in the forests of Nagano, I noticed a fascinating sight: droplets of water lined up along the edges of the leaves of a plant I presumed to be Japanese honewort (Cryptotaenia canadensis). This is known as “guttation”—a phenomenon whereby excess water drawn up by the roots seeps out as liquid through the stomata on the edges or tips of the leaves. Apparently, this occurs because transpiration is low and root pressure is increasing at night, which is why the droplets can be observed in the morning.

長野の森の朝、ミツバと思われる植物の葉の縁に水滴が並んでいて面白い。 溢泌と呼ばれ、根から吸い上げた水が余った際に、葉の縁や先端の水孔から液体としてにじみ出る現象だそう。夜は蒸散が弱く根圧が高まるため、朝に水滴として観察できる、というしくみらしい。

Nagano Pref. 長野県 2026-07-26

[hidemoriyazaki]

Sphragifera sigillata A moth with a distinctive and charming appearance. Whenever this species flies into the light trap during observation sessions, it instantly becomes the centre of attention. Its white-coloured scales also have a distinctive lustre, giving them a glossy appearance.

マルモンシロガ わかりやすくかわいらしい姿の蛾。ライトトラップ観察会で飛んでくると、一躍注目を集める存在。 地色の白い鱗粉も、独特の光沢があってつややかに映える。

Nagano Pref. 長野県 2025-07-24

[hidemoriyazaki]

Biston regalis The genus Biston, renowned for the “Industrial melanism” seen in the Peppered moth, B. betularia, is usually associated in Japan with notable spring species; thus, the presence of this beautiful species—which is representative of the summer mountains—brings a sense of joy, much like reuniting with a dear old friend at a school reunion. The specific epithet, meaning "Royal", is truly worthy of its noble stature.

ハイイロオオエダシャク 「工業暗化」のオオシモフリエダシャクで高名なBiston属は、日本では春の大物が多いので、夏の山地を代表する美しい本種との出会いは、懐かしい旧友に同窓会で再会するよう。「王者」を意味する種小名は、その高貴な佇まいにふさわしい。

Nagano Pref. 長野県 2026-07-25

[hidemoriyazaki]

A species of Pyrgotidae, would Adapsila fusca be the correct identification? As its Japanese name suggests, its wasp-like appearance is intriguing; however, it is also fascinating that, in overseas species of the same family, internal parasitism of adult scarab beetles has been recorded, and unusual behaviours—such as laying eggs whilst the host is in flight—have long been reported (e.g. Davis 1919).

デガシラバエ科の一種。フトハチモドキバエでよいでしょうか。 和名通りハチに似た姿が面白いが、海外の同科ではコガネムシ科成虫への内部寄生が記録され、宿主の飛翔時の産卵などの特異な行動が古くから報告されている (e.g. Davis 1919) ことも興味を惹かれる。

Nagano Pref. 長野県 2026-07-24

[hidemoriyazaki]

How marvellous is the Nun Moth, Lymantria monacha. The dynamic black wave patterns stand out brilliantly against its pure white, three-dimensional dress. Both the Japanese name (nonne, from German) and the specific epithet (monacha, from Latin) are said to mean ‘nun’, though she is certainly a rather avant-garde nun. Moths are truly beautiful.

素晴らしきかな、ノンネマイマイ 立体感のある純白のドレスに、ダイナミックな黒の波模様が映える。 和名 (nonne/ドイツ語) 、種小名 (monacha/ラテン語) は、共に「修道女」の意味だそうだが、なかなかアバンギャルドな修道女ではある。 蛾は、本当に美しい。

Nagano Pref. 長野県 2026-07-24

[hidemoriyazaki]

Unfortunately, the nighttime nature observation event had to be cancelled due to the heavy rain in Tokyo, so we brought our plans forward and carried out our survey in Nagano. The first to greet me was Amblychia insueta, a magnificent geometrid moth, typical of summer. With wings as splendid as an ink-wash painting adorned with clouds of gold dust, it continues to flutter gracefully around the light trap.

東京の豪雨で残念ながら夜間観察会が中止になったので、予定を早めて長野で調査。 出迎えてくれたのは、チャマダラエダシャク。夏を代表する雄大なシャクガの仲間。水墨画に金粉の雲を描いたような華麗な翅で、ふわりと優雅に灯火の周りを舞い続けている。

Nagano Pref. 長野県 2026-07-24

[hidemoriyazaki]

Black-faced Bunting (Emberiza personata) Whilst this species is generally regarded as a winter visitor, in Karuizawa highland, it is actually a summer resident. Beautiful mating calls heralding the breeding season, rarely heard in Tokyo, can be heard from all over the neighbourhood in the highland town.

アオジ 冬鳥の印象の強い本種だが、高原の軽井沢ではむしろ夏にやってくる鳥。 東京ではなかなか耳にすることのない繁殖に向けた美しいさえずりの声が、町内の各地から聞こえてくる。

Nagano Pref. 長野県 2026-05-30

[hidemoriyazaki]

The main actors of Karuizawa’s grasslands: the Chestnut-eared Bunting (Emberiza fucata). All over the grassy areas, the males face upward and sing loudly. The local specimens seem quite wary, so I was delighted to observe their behaviour closely after moving very cautiously.

軽井沢の草原の主役、ホオアカ。 草むらのあちこちで、オスたちは上を向いて高らかにさえずる。 当地の個体はそれなりに警戒心が強い印象で、かなり慎重に動いたところ、じっくりその行動を観察できてよかった。

Nagano Pref. 長野県 2026-05-30

[hidemoriyazaki]

My work has been selected for the "Photographic Series" category at the Karuizawa Foto Fest 2026. Entitled "Moths Calendar: A Year of Moths in Karuizawa", it features 10 moths that have visited my home in Karuizawa throughout the four seasons. Through the photographs, I would be delighted to convey the profound fascination of nocturnal nature and serve as a gateway to the marvellous world of insects.

My photograph is currently on display outdoors at Hotel Kajiima no Mori in Karuizawa until 21 June, alongside the works of other prize-winners and selected artists in the group photography category, and is also available to view on the Karuizawa Foto Fest website.

軽井沢フォトフェスト2026「組写真部門」で入選しました。 『Moths Calendar 〜軽井沢の蛾の一年〜』と題して、軽井沢の自宅にやってきた春夏秋冬の蛾を集めました。 写真を通じて、夜の自然の奥深い魅力を伝えることができたら、そして昆虫の驚くべき世界に触れるきっかけになれば、嬉しいです。

写真は、軽井沢のホテル鹿島ノ森で6月21日(日)まで、他の組写真部門の入賞者・入選者の作品とともに野外展示されているほか、フォトフェストのHPでも公開されています。

KFF Award 2026 Exhibition — Karuizawa Foto Fest

[hidemoriyazaki]

An Oriental Reed Warbler (Acrocephalus orientalis) singing on a power line near a reed bed. Its imposing form somehow reminds me of a dinosaur (though I suppose that makes sense, since it’s a descendant).

芦原の近くの電線の上でさえずっていたオオヨシキリ。 そのいかつさには、どことなく恐竜を思い出す（子孫だからそりゃあそうなんだけれど）。

Nagano Pref. 長野県 2026-05-30

[hidemoriyazaki]

A queen of Polistes chinensis nesting among the grasses of a highland meadow. Since she builds the nest, lays the eggs, and raises the larvae all by herself, the queen must be extremely busy. Perhaps due to the high temperatures, she was often seen flapping her wings continuously—a behaviour that appeared to create a breeze for the young in the nest.

高原の下草の間で営巣するフタモンアシナガバチの女王。 女王は1頭だけで、家を建て、卵を産み、生まれた幼虫たちを育てるのだから、大忙しのはず。 気温が高かった影響か、羽ばたきを続けて巣の中の子供たちに風を送る（ように見える）行動もよく見られた。

Nagano Pref. 長野県 2026-05-30

[hidemoriyazaki]

In a Shinshu forest in early summer, Ponyalis quadricollis (I think). Insects in the family Lycidae contain toxic substances in their bodies and are considered models for the aposematic mimicry seen in various other insects. It’s interesting to see the distinct differences in the shape of the male and female antennae when they are copulating.

初夏の信州の森にて、カクムネベニボタル（だと思う）。 ベニボタル科の昆虫は体内に有毒な成分を持ち、さまざまな昆虫の警告色擬態のモデルになっていると考えられている。 交尾していると、雌雄の触角のかたちのはっきりした違いがわかって面白い。

Nagano Pref. 長野県 2023-05-31

[hidemoriyazaki]

During an insect survey on the coast, I was utterly astonished to discover a whale, about 2 metres long, stranded at the water’s edge. I immediately contacted the local government and a whale expert, and was informed it was a Risso’s dolphin (Grampus griseus). It is said that the Japanese name "Flower" derives from the white marks on its body, which were caused by other individuals or squid. Although it looked quite weak and in a serious condition, the sheer power of its movements—flapping its fins and spouting water from time to time—was truly magnificent. Since an expert would be managing the situation, I left the place. However, I couldn’t tell whether it was the sound of breathing or a cry, but the low ‘boo’ sound the whale made kept echoing in my head long afterwards.

海岸で昆虫調査中、波打ち際に体長2mほどの生きたクジラが横たわっているのを見つけて仰天。 すぐに自治体と専門家の方に連絡すると、ハナゴンドウと教えて頂く。和名の「ハナ」は、他個体やイカなどにつけられてできる体の白い傷が由来とのこと。 かなり弱っていたけれど、ヒレをばたつかせたり、潮を吹いたりする動きの力強さは、やはりクジラのすごい迫力。 専門家の方にご対応頂けるということで、私はその場を離れたものの、呼吸の音なのか、鳴き声なのか、クジラの発する「ボオッ」という低い音が、その後もずっと頭から離れずにいる。

Shizuoka Pref. 静岡県 2026-05-25

[hidemoriyazaki]

Copulation of Libelloides ramburi As the female takes flight from the grassy area, males swarm in from all around, flying at high speed. They quickly form a pair in mid-air and glide down to the undergrowth. It was a lovely morning, with plenty of such behaviour to observe. In the photo, the top is the male and the bottom is the female.

キバネツノトンボの交尾 草むらからメスが飛び立つと、周囲からオスたちが高速で飛びながらわーっと集まってくる。すぐに空中でペアが成立し、下草などにすっと降りていく。そんな行動がたくさん観察できた、よい朝。 写真は上がオス、下がメス。

Nagano Pref. 長野県 2026-05-16

[hidemoriyazaki]

One of the truly wonderful aspects of nature in Karuizawa is the large numbers of Chestnut-cheeked Starling (Agropsar philippensis) coming to town each spring. Three years ago, they nested in the old tree in front of our house, and I enjoyed quietly watching them raise their chicks. This year, too, a beautiful male was singing in the morning sun atop a fir tree.

軽井沢の自然の素晴らしい魅力だと思うことの1つが、春になるとコムクドリがたくさん街にやってくること。3年前には家の前の古い木に営巣して、子育てをそっと観察できたのも楽しかった。 今年も美しいオスが、モミの木の上で朝日を浴びてさえずっていた。

Nagano Pref. 長野県 2026-05-11

[hidemoriyazaki]

Siberian Blue Robin (Larvivora cyane) Although I had often heard its distinctive song echoing through the highland forest, this blue bird—which rarely emerges from the undergrowth—finally allowed me to see it up close. It flew off immediately, making it truly a fleeting encounter.

コルリ 高原の森に響き渡る特徴的なさえずりはたびたび耳にしても、なかなか藪の中から出てきてくれない青い鳥と、ようやく間近に出会うことができた。すぐに飛んでいってしまったので、本当に一瞬の邂逅。

Nagano Pref. 長野県 2026-05-09