Longicorn beetle - Longicorn beetle

A general term for insects belonging to the family Cerambycidae, order Coleoptera, class Insecta. They are also commonly known as hair cutters. They are widely distributed throughout the world, with over 30,000 known species. Currently, close to 700 species are known to occur in Japan.

Small species have a body length of about 3 mm, but large species such as the South American giant longhorn beetle Titanus giganteus can reach 20 cm. In Japan, the large ones are the white-striped longhorn beetle and the long-horned longhorn beetle, but several Ussuri giant longhorn beetles, Callipogon relictus , which are found in the Korean Peninsula and Eastern Siberia and reach 10 cm in length, have been collected near Miyazaki City. The body shape is generally long and slender in many species, and the antennae are attached to the protuberance of the head, long and bent backwards, and often much longer than the body length. The mandibles are strong and sharp, and as the name suggests, they can cut hair, thread, and thin twigs. There are two spines at the tip of the tibia, and the tarsus has five segments, with the third segment spreading out like a leaf, and a small, tuberculate fourth segment above it.

When they catch a long-horned beetle, they make a sound by moving their prothorax, which is done by rubbing the rear edge of the pronotum against the file surface consisting of fine horizontal lines on the mesothorax; in saw-toothed long-horned beetles, they make the sound by rubbing the side edge of the upper wing against the femur of the hind legs. Adults are found in abundance on dead trees, fallen trees, cut trees and firewood, but can also be found on the trunks, branches and leaves of living trees, and many species, such as flower long-horned beetles, gather around flowers. Some also live in grasslands. Most of the larvae feed by drilling holes in the subcutaneous tissue or wood of dead trees, cut trees or trunks and branches of living trees on which they have laid their eggs. They are milky white in color and have a large and somewhat wide prothorax, and are commonly known as gun bugs. Their legs have degenerated, and they move using flat, octopus-like suction cup-like bumps on the top and bottom of their abdomens, through which they often make holes and expel wood chips. In Japan, wood sawyer beetles have long been used as a medicine for epilepsy, but in tropical regions they are a form of food for indigenous people. Other species that infest herbaceous plants include the Asa longhorn beetle and Ramie longhorn beetle, which feed on the inside of stems and roots, and the Red longhorn beetle and Grey longhorn beetle, which are known to damage bamboo, making them pests in agriculture, forestry, and horticulture. Recently, it has been discovered that the pine sawyer beetle transmits the pinewood nematode in connection with the death of pine trees, and extermination is being carried out.

The classification of the Longhorn Beetle family varies slightly among researchers and may be divided into several families, but they are usually divided as follows:

(1) The subfamily Ophiopogoninae is brown to black, with ridges on both sides of the prothorax. It includes the sawtooth longhorn beetle, the antler longhorn beetle, and the Bates longhorn beetle.

(2) Subfamily: Long-horned beetles: Flat and parallel on both sides, with mandibles that protrude forward and antennae that are short and bead-shaped.

(3) Longhorn Beetles: They are native to South America and are not like longhorn beetles, with extremely short antennae. Some live in treeless areas, and females live by digging holes in the ground.

(4) Subfamily: A small number of species are found in Southeast Asia, and are considered to be the most primitive subfamily.

(5) Subfamily: Longhorn Beetles This subfamily includes long, slender species. There are two species native to Japan: Longhorn Beetle (Longhorn Beetle) and Longhorn Beetle (Longhorn Beetle).

(6) Subfamily Cerambycidae: The head and neck are usually thin, the prothorax has no lateral margins, and most are bell-shaped. Most of them gather around flowers. There are many species, such as the red cerambycidae and the four-striped cerambycidae.

(7) Longhorn Beetles: The head has a narrow neck and a rounded prothorax. There are many black or brown species, such as the black longhorn beetle and the rust longhorn beetle.

(8) Cerambycidae: The head is usually inclined obliquely forward, and the file surface of the mesonotum is not divided into two. This includes beautiful species such as the blue-spotted longhorn beetle, the green longhorn beetle, and the tiger longhorn beetle, as well as the unusual-shaped longhorn beetle.

(9) Subfamily: The front of the head is vertical or more inclined, and the mouth is downward. This is the largest group in the family, and about half of the long-horn beetles belong to this group. In addition to the white striped long-horn beetle and the yellow spotted long-horn beetle, which damage living trees, the ash-leaf long-horn beetle and the ramie long-horn beetle, which damage herbs, many of them live on dead trees.

[Takehiko Nakane]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

昆虫綱甲虫目カミキリムシ科Cerambycidaeに属する昆虫の総称。俗にケキリムシ（毛切虫）ともいう。世界中に広く分布しており、3万種以上の種が知られている。日本でも現在700に近い種が産することがわかっている。

　体長は小さいものは3ミリメートルぐらいのものがあるが、大形の種は南アメリカのオバケオオウスバカミキリTitanus giganteusのように20センチメートルにも達するといわれるものがある。日本産ではシロスジカミキリ、ヒゲナガカミキリが大きいが、朝鮮半島、東シベリアに分布する10センチメートルに達するウスリーオオカミキリCallipogon relictusが宮崎市付近で数匹採集されたことがある。体形は一般に長く、細長い種も多く、触角は頭の隆起上につき、長くて後方へ曲げられ、しばしば体長よりはるかに長い。大あごは頑丈で鋭く、名のように毛髪や糸、細枝などを切断できる。脛節(けいせつ)先端には2本の棘(とげ)があり、跗節(ふせつ)は5節で第3節が葉片状に広がり、その上に小さくて結節状の第4節がつく。

　カミキリムシを捕まえると、前胸を動かして発音するが、これは、前胸背板の後縁と中胸背板にある細かい横線からなるやすり面をこすり合わせるためで、ノコギリカミキリ類では上ばねの側縁と後脚(こうきゃく)の腿節(たいせつ)をこすり合わせて発音する。成虫は枯れ木、倒木、伐採木や薪(まき)に多く、生木の幹や枝、葉にもおり、ハナカミキリなどのように花に集まるものも少なくない。また、一部に草地にすむものもある。幼虫は、卵を産み付けられた枯れ木や伐採木あるいは生木の幹や枝の皮下や材部に孔(あな)をあけて食害するものが大部分で、乳白色で前胸部が大きくやや幅広く、俗にテッポウムシ（鉄砲虫）とよばれる。これらは脚(あし)が退化し、腹部の上下にある平たいタコの吸盤状の瘤起(りゅうき)を使って運動し、孔をあけた木くずは孔から外へ出すことが多い。テッポウムシは日本では古くから癇(かん)の薬として用いられたが、熱帯域では原住民の食料の一つになっている。ほかに草本類につく種類では茎や根の内部を食害するアサカミキリやラミーカミキリなどがあり、竹材を害するものにはベニカミキリやハイイロヤハズカミキリなども知られ、農林業や園芸上の害虫が多い。最近もマツの枯死に関連してマツノマダラカミキリがマツノザイセンチュウを媒介することが明らかになり、その駆除が行われている。

　カミキリムシ科の分類は、研究者により多少異なり数科に分けられることがあるが、普通次のように分ける。

(1)ノコギリカミキリ亜科　褐色から黒色、前胸の両側は稜(りょう)状になっている。ノコギリカミキリ、ウスバカミキリ、ベーツヒラタカミキリなどが含まれる。

(2)ニセクワガタカミキリ亜科　平たくて両側平行し、大あごは前方へ突出し、触角は短く数珠(じゅず)状。

(3)ケラモドキカミキリ亜科　南アメリカ産でカミキリらしくなく、触角はきわめて短い。一部は木のない地帯にすみ、雌は地面に穴を掘ってすむという。

(4)コウセンカミキリ亜科　東南アジアに少数の種が産し、もっとも原始的な類とされる。

(5)ホソカミキリ亜科　細長い種を含み、日本産はホソカミキリ、オオクボカミキリの2種。

(6)ハナカミキリ亜科　頭は首が普通細く、前胸は側縁がなく、多くは鐘形、大部分は花に集まる。アカハナカミキリ、ヨツスジハナカミキリなどかなりの種がある。

(7)マルクビカミキリ亜科　頭は首がくびれ、前胸は丸みがある。クロカミキリ、サビカミキリなど黒ないし褐色の種が多い。

(8)カミキリ亜科　頭は普通斜めに前方に傾き、中胸背のやすり面は二分されない。ルリボシカミキリ、アオカミキリ、トラフカミキリなどきれいな種類や形の変わったモモブトコバネカミキリの類などが含まれる。

(9)フトカミキリ亜科　頭の前部は垂直かそれ以上傾き、口は下向きにつく。科のなかで最大の群で約半数のカミキリはここに属する。シロスジカミキリ、キボシカミキリなど生木を害するもの、草本につくキクスイカミキリ、ラミーカミキリなどのほか多くが枯木につく。

［中根猛彦］

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