Aquatic insects or water insects live some portion of their life cycle in the water. They feed in the same ways as other insects. Some diving insects, such as predatory diving beetles, can hunt for food underwater where land-living insects cannot compete.
The insect order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order consists of some 6,000 species. Neuroptera is grouped together with the Megaloptera and Raphidioptera (snakeflies) in the unranked taxon Neuropterida.
Holometabola, also known as Endopterygota, is a superorder of insects within the infraclass Neoptera that go through distinctive larval, pupal, and adult stages. They undergo a radical metamorphosis, with the larval and adult stages differing considerably in their structure and behaviour. This is called holometabolism, or complete metamorphism.
Green lacewings are insects in the large family Chrysopidae of the order Neuroptera. There are about 85 genera and 1,300–2,000 species in this widespread group. Members of the genera Chrysopa and Chrysoperla are very common in North America and Europe; they are very similar and many of their species have been moved from one genus to the other time and again, and in the nonscientific literature assignment to Chrysopa and Chrysoperla can rarely be relied upon. Since they are the most familiar neuropterans to many people, they are often simply called "lacewings". Since most of the diversity of Neuroptera are properly referred to as some sort of "lacewing", common lacewings is preferable.
Dobsonflies are a subfamily of insects, Corydalinae, part of the Megalopteran family Corydalidae. The larvae are aquatic, living in streams, and the adults are often found along streams as well. The nine genera of dobsonflies are distributed in the Americas, Asia, and South Africa.
Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago. Holometabolism is a synapomorphic trait of all insects in the superorder Holometabola. Immature stages of holometabolous insects are very different from the mature stage. In some species the holometabolous life cycle prevents larvae from competing with adults because they inhabit different ecological niches. The morphology and behavior of each stage are adapted for different activities. For example, larval traits maximize feeding, growth, and development, while adult traits enable dispersal, mating, and egg laying. Some species of holometabolous insects protect and feed their offspring. Other insect developmental strategies include ametabolism and hemimetabolism.
Snakeflies are a group of predatory insects comprising the order Raphidioptera with two extant families: Raphidiidae and Inocelliidae, consisting of roughly 260 species. In the past, the group had a much wider distribution than it does now; snakeflies are found in temperate regions worldwide but are absent from the tropics and the Southern Hemisphere. Recognisable representatives of the group first appeared during the Early Jurassic. They are a relict group, having reached their apex of diversity during the Cretaceous before undergoing substantial decline.
Mantispidae, known commonly as mantidflies, mantispids, mantid lacewings, mantisflies or mantis-flies, is a family of small to moderate-sized insects in the order Neuroptera. There are many genera with around 400 species worldwide, especially in the tropics and subtropics. Only five species of Mantispa occur in Europe. As their names suggest, members of the group possess raptorial forelimbs similar to those of the praying mantis, a case of convergent evolution.
Ascalaphidae is a family of insects in the order Neuroptera, commonly called owlflies; there are some 450 extant species. They are fast-flying crepuscular or diurnal predators of other flying insects, and have large bulging eyes and strongly knobbed antennae. The larvae are ambush predators; some of them make use of self-decoration camouflage.
Fishflies are members of the subfamily Chauliodinae, belonging to the megalopteran family Corydalidae. They are most easily distinguished from their closest relatives, dobsonflies, by the jaws (mandibles) and antennae. In contrast to the large jaws of dobsonflies, fishfly mandibles are not particularly noticeable or distinctive, and the males have feathery antennae similar to many large moths. Chauliodes pectinicornis, the "summer fishfly", is a well-known species in North America.
Hemerobiidae is a family of Neuropteran insects commonly known as brown lacewings, comprising about 500 species in 28 genera. Most are yellow to dark brown, but some species are green. They are small; most have forewings 4–10 mm long. These insects differ from the somewhat similar Chrysopidae not only by the usual coloring but also by the wing venation: hemerobiids differ from chrysopids in having numerous long veins and forked costal cross veins. Some genera are widespread, but most are restricted to a single biogeographical realm. Some species have reduced wings to the degree that they are flightless. Imagines (adults) of subfamily Drepanepteryginae mimic dead leaves. Hemerobiid larvae are usually less hairy than chrysopid larvae.
The Neuropterida are a clade, sometimes placed at superorder level, of holometabolous insects with over 5,700 described species, containing the orders Neuroptera, Megaloptera, and Raphidioptera (snakeflies).
Nymphidae, sometimes called split-footed lacewings, are a family of winged insects of the order Neuroptera. There are 35 extant species native to Australia and New Guinea.
Psychopsidae is a family of winged insects of the order Neuroptera. They are commonly called silky lacewings.
Sisyridae, commonly known as spongeflies or spongillaflies, are a family of winged insects in the order Neuroptera. There are approximately 60 living species described, and several extinct species identified from the fossil record.
The dustywings, Coniopterygidae, are a family of Pterygota of the net-winged insect order (Neuroptera). About 460 living species are known. These tiny insects can usually be determined to genus with a hand lens according to their wing venation, but to distinguish species, examination of the genitals by microscope is usually necessary.
Alderflies are megalopteran insects of the family Sialidae. They are closely related to the dobsonflies and fishflies as well as to the prehistoric Euchauliodidae. All living alderflies – about 66 species all together – are part of the subfamily Sialinae, which contains nine extant genera.
Myrmeleontiformia is an insect clade in the order Neuroptera, and which was historically treated as a suborder. The phylogeny of the Neuroptera has been explored using mitochondrial DNA sequences, and while issues remain for the order as a whole, such as "Hemerobiiformia" being paraphyletic, Myrmeleontiformia is generally agreed to be monophyletic, with one study giving the following cladogram:
Archichauliodes diversus is an insect in the subfamily Chauliodinae - the fishflies, though it is often referred to as the New Zealand dobsonfly, despite not being a true dobsonfly. In its larval form it is commonly known by the name toe-biter, and its Māori name is puene. The species is native to New Zealand. Although there are many other species of fishfly in other parts of the world, Archichauliodes diversus is the only species of fishfly in New Zealand.
