Neuroptera - Myakushirui

Neuroptera is a relatively primitive group of insects that undergo complete metamorphosis. It includes three groups: the Megapteridae, which includes the dragonfly and the Swertia japonica, the Camelidae, and the Planoptera, but in a narrow sense it can refer to the third group, the Planoptera. The adults of this group are terrestrial, and the larvae are also terrestrial, except for the Megapteridae and some Planoptera, which are aquatic and have tracheal gills on both sides of the abdominal segment, and pierce the prey with their sharp mandibles and suck out the body fluids. The wings of the adult insects are quite multi-veined and more or less reticulated by the transverse veins, and the veins are often hairy. The antennae are often thread-like, but can also be comb-like or bead-like, and some species have slightly swollen tips like those of horned dragonflies. The eyes are quite large, and some species, such as lacewings, have three simple eyes. The legs are thin and the tarsus has five segments. Larvae often have large heads and are very mobile, with long, protruding mandibles and mandibles, the mandibles being tightly attached to grooves along the inside of the mandibles and acting as suckers. They usually pupate after three instars, and before pupation they release silk from the tail end and create an egg- or spindle-shaped cocoon. The silk is said to be released from the end of the Malpighian tubules. The pupae are naked and mobile, and some escape from the cocoon before emerging.

There are approximately 10,000 known species in the world, but the first two classes are few in number, while the majority are flat-winged dragonflies, which are roughly divided into four classes: the meal fly, the false mantis, the venus (including lacewings), and the ant mayfly (including horned dragonflies). Of these, the larvae of the ant mayfly are known as antlions, and the parasitic false mantis is known to undergo hypermetamorphosis.

[Takehiko Nakane]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

完全変態をする昆虫のなかで比較的原始的な一群Neuropteraをいう。これにはヘビトンボとセンブリの属する広翅(こうし)類、ラクダムシ類、扁翅(へんし)類の3群が含まれるが、狭い意味では第三の扁翅類のことをさすことがある。この類の成虫は陸生であるが、幼虫も広翅類と一部の扁翅類が水生で腹節の両側に気管鰓(さい)をもつのを除けば、陸生であって、獲物に鋭い大あごを突き刺し体液を吸う。成虫のはねは脈がかなり多くて横脈で多少とも網状にくぎられ、脈には多くは毛がある。触角は糸状が多いが、櫛(くし)状や数珠(じゅず)状のこともあり、先がすこし膨れたツノトンボ類のようなものもある。目はかなり大きく、クサカゲロウなど一部の種では単眼3個を備える。脚(あし)は細く、跗節(ふせつ)は5節。幼虫は頭が大きいことが多く、よく動き、大あごと小あごは長くて突出し、大あごの内側に沿う溝に小あごが密着し、吸管の役目を果たす。三齢を経て蛹(さなぎ)になるのが普通で、蛹化(ようか)前に尾端から糸を出して卵形ないし紡錘形の繭をつくる。糸はマルピーギ管末端から出されるといわれる。蛹は裸蛹で運動可能であり、羽化前に繭から脱出するものもある。

　世界におよそ1万種が知られるが、初めの二類は少数で、扁翅類が大部分を占め、コナカゲロウ、カマキリモドキ、ヒメカゲロウ（クサカゲロウを含む）、ウスバカゲロウ（ツノトンボを含む）の四類に大別される。このうちウスバカゲロウの幼虫はアリジゴクとして知られ、寄生性のカマキリモドキは過変態をすることが知られている。

［中根猛彦］

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