Neuroptera (Lacewings)

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Neuroptera

(Lacewings)

Class Insecta

Order Neuroptera

Number of families 17

Evolution and systematics

Neuroptera represents one of the oldest and most archaic lineages of endopterygote (= holometabolous, or undergoing complete metamorphosis) insects. The oldest known fossils of Neuroptera suggest that the group had its origin in the early Permian period, with significant family level diversification in the late Triassic and early Jurassic. At the end of the Jurassic, however, all extant lineages had appeared, and at least three lineages (14 families) had become extinct. Truly spectacular lacewings that we know only from fossils include Kalligramma haeckelli and Lithogramma oculatum (Kalligrammatidae, Upper Jurassic), two species with distinctive eyespots in their large, brightly colored wings. Numerous families of lacewings are known only from fossils, including Kalligrammatidae, Nymphitidae, Permithonidae, Mesopolystoechotidae, Solenoptilidae, Allopteridae, and Osmylitidae. Moreover, many described fossil lacewings can be placed in extant families, including Permithonopsis obscura (Polystoechotidae), Embaneura vachrameevi (Psychopsidae), Plesiorobius (Berothidae), and Euporismites balli (Osmylidae).

Neuroptera comprises 17 extant families containing more than 6,000 species worldwide divided into three superfamilies. Myrmeleontidae (more than 2,000 spp.) and Chrysopidae (more than 1,200 spp.) are the most species-rich families, followed by Hemerobiidae (about 550 spp.) and Ascalaphidae (some 400 spp.). The superfamily Nevrorthiformia, with the single family Nevrorthidae, represents the most basal group; members of this family are sporadically found in Japan, Taiwan, Australia, and Europe. The Myrmeleotiformia contains five families (Myrmeleontidae, Ascalaphidae, Nemopteridae, Psychopsidae, and Nymphidae). It is a well-defined group of generally large lacewings with soil-dwelling or arboreal larvae. The Hemerobiiformia, made up of 11 families (Hemerobiidae, Chrysopidae, Sisyridae, Berothidae, Mantispidae, Rhachiberothidae, Ithonidae, Polystoechotidae, Dilaridae, Coniopterygidae, and Osmylidae), is a morphologically diverse assemblage of lacewings, many of which have unique and highly specialized life cycles. Ithonidae are robust, moth-like lacewings with fossorial, scarab-like larvae associated with roots of trees and bushes (e.g., creosote). This family and the sister family Polystoechotidae sometimes are considered the most basal clade of lacewings. Another clade, or group of closely related families, is the Dilaridae clade. This group comprises Dilaridae, Rhachiberothidae, Mantispidae, and Berothidae and is united by particular larval head characteristics.

Physical characteristics

Lacewing is a common name that describes the lace-like venation pattern of the relatively large, delicate wings of most adult Neuroptera. The adult body shape is relatively uniform across the order. The head is well defined, typically without setae or bristles (although dense tufts of long setae are found in many Ascalaphidae). The eyes are large, well defined, and spherical in shape; some ascalaphids have a horizontal sulcus (line) dividing the eyes into upper and lower regions. Well-defined ocelli (simple eyes) are present on the vertex only in the family Osmylidae. The mouthparts are chewing and directed either anteriorly or ventrally; in many Nemopteridae the mouthparts are extremely elongated. Antennae typically are very elongate and moniliform (simple) and rarely flabellate (Dilaridae); sometimes they have apical clubs (Ascalaphidae) or are thickened (Myrmeleontidae).

The thorax is divided into three segments, the posterior, wing-bearing segments being much larger than the anterior segment. Legs usually are slender and elongate; forelegs sometimes are raptorial (Rhachiberothidae and Mantispidae). The wings almost always are large and broad and rarely are reduced. Some species are brachypterous or apterous. The wing shape is elongate and oblong to elliptical or ovate; the margin either is round or falcate (hooked or curved). Venation is highly reticulate in most groups, although it is reduced to only a few veins in some (Coniopterygidae). The abdomen usually is long, and the genitalia on terminal segments either are reduced and concealed (Myrmeleontidae) or elaborate and exposed (Osmylidae and Nymphidae).

Larval body shape typically is campodeiform or, rarely, scarabaeiform. The head is dorsoventrally flattened, with mouthparts projecting anteriorly. The mouthparts are modified uniquely, such that the buccal (mouth) cavity is closed and sucking tubes are formed laterally by the interlocking of the mandibles and maxillae. Jaws are elongate, simple, or toothed and used to impale prey and suck out its contents. In Sisyridae and Osmylidae the jaws are extremely long and slender. In Myrmeleontiformia the jaws often are held open at more than 180 degrees and snapped closed to trap prey. Eyes comprise a group of five, six, or seven stemmata (rudimentary eyes), but eyesight is poor.

Antennae either are short or elongate. The thorax usually is short and broad, but in some Nemopteridae, the prothorax (anterior segment) may be lengthened into a neck. Legs are long in the active arboreal larvae (Chrysopidae), short in fossorial larvae (Myrmeleontidae and Ascalaphidae), or rudimentary in egg sac predators (Mantispidae). The abdomen may be elongate or ovate. The thorax and abdomen often have fleshy lateral projections (scoli) (Nymphidae) or long and recurved (Chrysopidae) or ornately shaped (Ascalaphidae) setae used to hold items of debris on the dorsum. Another unique characteristic of neuropteran larvae is that the midgut is discontinuous with the hindgut; solid waste is not passed until the adult emerges from the pupal case with a fully formed digestive system. Larvae spin pupal cases with silk produced from modified Malphigian tubules. The pupa is exarate and decticous and emerges from the pupal case to molt into a fully winged adult.

Distribution

Neuropterans are distributed throughout tropical and temperate regions, with the greatest species richness and diversity in the tropics. Several families (Myrmeleontidae, Chrysopidae, Hemerobiidae, Coniopterygidae, Mantispidae, and Ascalaphidae) are distributed widely, although particular subfamilies, genera, and species within each family are much more restricted. From fossil evidence it is clear that the former distribution of some groups was more extensive than today. Nemopteridae is a group of lacewings distributed throughout Africa, the Palaearctic region, Australia, and South America but absent in North America (although a fossil nemopterid has been found in Colorado). Psychopsidae are restricted to Africa, Asia, and Australia, while Nymphidae are found only in the Indonesian Archipelago, Papua New Guinea, and Australia. Some groups have highly disjunct, apparently relict distributions, also evidence of more extensive past distributions. Nevrorthidae, comprising 10 species with aquatic larvae, are found in Australia, Japan, Taiwan, and the Mediterranean region. Ithonidae (including Rapismatidae) are diverse in Australia but also are found in mountainous regions of Central America and Asia and in the southwestern United States.

Habitat

Lacewings are found in a wide variety of habitat types, from arid desert plains to montane rainforests. While adults typically are found on vegetation, larvae are more specific in their habitat requirements and often are associated with a particular substrate or prey type. Families such as Myrmeleontidae and Nemopteridae, with larvae that live in sandy soils, are adapted for existence in deserts and dry savannas and are particularly diverse and numerous in these regions around the world. Larvae of some species of antlion (Myrmeleontidae: Acanthoclisinae) can swim through loose sand in search of prey. Some lacewings, such as Chrysopidae and Hemerobiidae, are strictly arboreal as larvae on trees, shrubs, and grasses. Larvae of Psychopsidae are recorded inhabiting deep crevices in Eucalyptus spp. trees in dense forests in Australia. Larvae and adults of Coniopterygidae are found on foliage of trees and bushes, including some specific to particular vegetation types (e.g., Aleuropteryx juniperi). Larvae of both Nevrorthidae and Sisyridae are predators in freshwater streams, while larvae of some Osmylidae (e.g., Osmylus fulvicephalus in Europe and unidentified Kempyninae in Australia) live in the littoral zone of such streams under rocks and among leaf litter. Larvae of moth lacewings (Ithonidae) are fossorial, living among the roots of trees and shrubs. One example is Oliarces clara, the only North America ithonid, which is associated with the roots of the creasote bush (Larrea tridentata).

Behavior

Several neuropteran families possess various anatomical characteristics that apparently are involved in chemical communication between sexes during courtship. Males of Nevrorthidae and some Myrmeleontidae possess eversible pleurocavae on the abdomen, whereas males of Nemopteridae have a bulla on the wing margin or wing base; both are used to disperse chemical pheromones. Males of some Mantispidae possess an Eltringham organ on the abdomen, which also is used in the dispersal of mating chemicals. There is complicated communication among Chrysopidae involving abdominal vibrations (Chrysoperla) or wing "rapping" (Mallada spp.), resulting in complex "calls" that are communicated via the substrate. Various defensive behavioral mechanisms are employed by different lacewings to evade or deter predators.

While most adult neuropterans remain inactive during the day, relying on camouflage to escape detection, some engage in various forms of behavior to make the deception more complete. The families that have setae holding items of debris on the dorsum use this "trash packet" as camouflage and as a shield against predators. Beaded lacewings (Berothidae) commonly begin gently swaying when a potential predator is detected, apparently to simulate a twig being moved by a breeze. When disturbed, certain lacewings feign death (some Hemerobiidae and Chrysopidae), whereas others emit an offensive odor (Nymphes spp. of Nymphidae and Plesiochrysa spp. of Chrysopidae). Some Mantispidae (Euclimacia spp. and Climaciella spp.) are effective mimics of paper wasps (Vespidae) in color and shape and also adopt postures and movements resembling the paper wasp when disturbed. Some first instar larvae of Mantispidae have been shown to follow a series of obligatory behavioral cues when searching for a suitable host spider egg sac. Larvae of Climaciella brunnea must board an adult spider before they enter the egg sac. If placed on a spider and not allowed to board, they simply climb to the highest point of the spider and assume a questing posture to look

for another passing spider they can board. Upon hatching, larvae of Ascalaphidae and Nymphidae (Nymphes) group together for a period of time with jaws outstretched in an apparent defensive posture.

Feeding ecology and diet

Lacewings typically are generalist predators as larvae and adults, although there are exceptions; in several families, the larva has become highly specialized in its feeding ecology and diet. Many lacewing adults may be generalist omnivores, feeding opportunistically on soft-bodied insects, pollen, and honeydew. Adults of Nemopteridae and some Chrysopidae are obligate feeders on pollen and nectar from flowers, with many nemopterids having greatly elongated mouthparts modified for insertion into flowers with long corollas (where separate or fused flower petals come together and often form a long tube). Predatory adult Mantispidae and Rhachiberothidae have raptorial forelegs for seizing and holding prey, and many adult antlions (Myrmeleontidae: Acanthoclisinae) and owlflies (Ascalaphidae) have elongated claws and long, stiff bristles and spines on their legs for capturing prey in flight.

In most families the larvae are either sedentary "sit-and-wait" predators, waiting for hapless prey to walk into their open jaws (Ascalaphidae and Nymphidae), or active foragers, scouring the tactile landscape in search of prey items (Chrysopidae, Hemerobiidae, and Coniopterygidae). Larvae of some antlions (Myrmeleontidae: Myrmeleon spp.) construct conical pits in the sand and wait at the bottom with only their large jaws exposed. When a suitable prey falls into the pit, the antlion larva tosses sand upward with its head to dislodge the prey, so that it falls into its open jaws and then is dragged beneath the surface of the sand to be consumed. Larvae of Ithonidae and, presumably, Polystoechotidae are the only non-carnivorous lacewings, with short blunt jaws not suitable

for impaling prey as other lacewings do. On the contrary, Ithonid larvae feed on root exudates of trees and bushes.

Among the families with aquatic larvae, Nevrorthidae are generalist predators in fast-flowing streams, while spongilla flies (Sisyridae) are obligate specialist predators of freshwater sponges and bryozoans. Sisryid larvae have highly modified jaws that are extremely long (often longer than the body) and narrow and are used to pierce individual cells of their sponge prey delicately. Semiaquatic larvae of Osmylidae use their long jaws to probe the wet soil and mud in search of soft-bodied prey, for example, larvae of Chironomidae (Diptera). Larvae of some families (Dilaridae, Osmylidae, and Psychopsidae) live under bark and in deep bark crevices, where they are generalist predators on a variety of arthropods living there. Beaded lacewing (Berothidae) larvae live as specialized predators on subterranean termites. Fragmentary evidence suggests that the larvae either secrete an allomone or inject a neuro-toxin to immobilize their termite prey, on which they then can feed safely. The first and third instar larvae actively feed on termites, but the second instar is an inactive resting stage.

Larvae of Mantispidae are obligate, specialized predators on either social hymenoptera nests (Symphrasinae) or spider egg sacs (Mantispinae). In larvae that prey on spider eggs sacs, the active first instar triungulin larva seeks out a suitable host spider, which it boards and ultimately enters the egg sac. Once it is in the egg sac, the second and third instars take on a physiogastric form (i.e., hypermetamorphic development, or dramatic change in overall morphological features between instars). The larvae also may arrest the development of the spider eggs by chemical means to prevent them from hatching. There appears to be some level of host specificity.

Reproductive biology

Mating either is brief or takes place over an extended period of time, usually through solitary encounters between the sexes. Mating swarms have been recorded for Ithone in Australia and Oliarces in the United States. Eggs are laid either solitarily or in batches on substrate, in crevices, or on silken stalks (certain Nymphidae, Mantispidae, and Chrysopidae). Ascalaphidae often deposit infertile eggs (repagula) between their fertile eggs and the probable path of potential egg predators. Some species of Mantispidae lay hundreds of eggs, presumably because of the high mortality rate faced by the minute first instar larvae as they seek out suitable spider egg sacs. There is little or no parental care after oviposition.

Conservation status

Owing to the often high degree of regional endemicity and low degree of vagility, many neuropterans are particularly vulnerable to extinction from pollution and habitat alteration by human activities. Other species are large and brightly colored (Libelloides spp. and Nemoptera spp.), making localized populations susceptible to being overly collected by amateur collectors. At present no species of lacewing is listed by the IUCN worldwide. In various countries around the world, there are national, state, or local regulatory lists of protected species or populations of neuropterans.

In the United States several species of neuropterans are considered endangered, with legislated protection in some states (e.g., California and Hawaii). These species include Nothochrysa californica (Chrysopidae), Oliarces clara (Ithonidae),

Distoleon perjerus (Myrmeleontidae), Pseudopsectra usingeri (Hemerobiidae), and three species of Micromus (Hemerobiidae). In South Africa species of lacewing considered critically endangered due to habitat destruction include Pamexis bifasciatus, P. contamminatus, Exaetoleon obtabilis (all Myrmeleontidae); Sicyoptera dilatata, S. cuspidata, Halterina pulchella; and H. purcelli (all Nemopteridae).

Significance to humans

As beneficial generalist predators, lacewings from at least three families (all with arboreal larvae) have been used in biological control of arthropod pests in agriculture. Coniopterygidae have long been recognized to have considerable potential for biological control, particularly of spider mites (Tetranychidae) in greenhouses and orchards. Two families, Chrysopidae and Hemerobiidae, are used on a commercial scale to control arthropod pests in numerous field and greenhouse crop situations. Chrysopids from various genera (Mallada, Chrysoperla, and Chrysopa) are reared in large numbers in commercial insectaries for inundative release among various crops for successful control of many arthropod pests. Hemerobiids also are reared for inundative release but are used less commonly in commercial situations.

Species accounts

List of Species

Beaded lacewing
Green lacewing
Moth lacewing
Mantid lacewing
Antlion
Spoonwing lacewing
Norfolius

Beaded lacewing

Spermophorella maculatissima

family

Berothidae

taxonomy

Spermophorella maculatissima Tillyard, 1916, Brisbane, Queensland, Australia.

other common names

None known.

physical characteristics

Relatively small lacewings. Short, narrow body, with wings held vertically over the abdomen. Wings have speckled black, brown, and white pattern on wing veins to aid in camouflage. Body and wing veins are covered with long setae. Newly hatched larvae are elongate with short jaws. Later instars unknown.

distribution

Queensland, Australia.

habitat

Arid regions, particularly in open sclerophyll forests.

behavior

Adults remain motionless during the day, with the antennae held out in front of the head. They sway their bodies when potential predators are near.

feeding ecology and diet

Adults probably are generalist feeders. The larvae of all known berothids are obligate predators on subterranean termites. Larvae presumably use an allomone to subdue their termite prey. First and third instars are active feeders, whereas the second instar is a sedentary, resting stage.

reproductive biology

Adult females lay solitary eggs on long, silken stalks. It is thought that the first instar triungulin larvae seek out and enter a suitable termite colony, where they can remain undetected by the termites. The larvae undergo hypermetamorphic development.

conservation status

Not listed by the IUCN.

significance to humans

None known.

Green lacewing

Mallada albofascialis

family

Chrysopidae

taxonomy

Mallada albofascialis Winterton, 1995, Brisbane, Queensland, Australia.

other common names

None known.

physical characteristics

Relatively small lacewings. The body is elongate and delicate, with broad wings that have characteristic open, "chrysopid-type" venation. The body is light to dark green in color, with red patches on the prothorax and head. The face also has a distinctive

white area above the mouth. The larva has an elongate body and carries a trash packet within special curved hairs on its back, used for camouflage.

distribution

Northern Territory and coastal Queensland, Australia.

habitat

Forested areas.

behavior

Nothing is known.

feeding ecology and diet

Adults feed on honeydew and flower nectar. The larva is an arboreal generalist predator feeding on a variety of soft-bodied arthropods, especially mealybugs (Hemiptera: Margarodidae).

reproductive biology

Adult females lay eggs on long silken stalks in patches of 10–15 eggs.

conservation status

Not listed by the IUCN.

significance to humans

None known.

Moth lacewing

Megalithone tillyardi

family

Ithonidae

taxonomy

Megalithone tillyardi Riek, 1974, Cunningham's Gap, Queensland, Australia.

other common names

None known.

physical characteristics

The moth lacewing is a relatively large, robust insect with an appearance similar to that of a dull hepialid moth. The wings and body are dull brown, and the body is covered with numerous long hairs. The wings are folded over the body. The larva is fossorial and scarabaeiform in body shape.

distribution

Southeastern Queensland and northern New South Wales, Australia.

habitat

Higher elevations, often on sandy soils.

behavior

Adults emerge in masses to form large mating aggregations or swarms composed of many more males than females.

feeding ecology and diet

It is not clear if adults feed, but the larvae eat root exudates of plants. Ithonids have been recorded erroneously as predators of scarab larvae.

reproductive biology

The female has a genital plug upon emergence, which is apparently displaced during copulation.

conservation status

Not listed by the IUCN. The conservation status of the moth lacewing is difficult to assess, because larvae are fossorial and adult swarms are infrequent. Habitat destruction appears to be the main threat to individual populations.

significance to humans

Swarms have been recorded hitting the metal roofs of houses and sounding like a hail storm. While they are rare, swarms are a nuisance to humans, because adults also enter houses and gather in dark places. Such plagues are known to last as long as three weeks.

Mantid lacewing

Euclimacia torquata

family

Mantispidae

taxonomy

Euclimacia torquata Navás, 1914, Queensland, Australia.

other common names

None known.

physical characteristics

Medium-size lacewings. The body is robust, with relatively narrow wings that are darkly pigmented along the anterior portion. This species has strongly contrasting black, yellow, and orange coloration, enabling it to be an effective wasp mimic. The front legs are raptorial. The immature stages are unknown.

distribution

Queensland, Australia, and Papua New Guinea.

habitat

Forested areas.

behavior

Adults fly and walk in a way similar to paper wasps, as a defense against predators.

feeding ecology and diet

Adults are generalist predators, using their raptorial forelegs to capture prey. Based on evidence from other mantid lacewings, the larva is presumably a specialized predator of spider egg sacs and probably also is highly host specific.

reproductive biology

Nothing is known.

conservation status

Not listed by the IUCN.

significance to humans

None known.

Antlion

Myrmeleon formicarius

family

Myrmeleontidae

taxonomy

Myrmeleon formicarius Linnaeus, 1767, Europe.

other common names

English: Doodlebug.

physical characteristics

Large, very long lacewing. The head and thorax are short and stout, and the abdomen is very elongate. Body is brown with tan markings; antennae are thickened apically. Wings very elongate, narrow, and hyaline. Venation is mottled brown, black, and white. Larvae are robust and ovoid-shaped with large curved jaws. Body is adapted for burrowing backward through sandy soil.

distribution

Western Europe.

habitat

A wide variety of habitats, especially sandy desert or savanna regions.

behavior

Adults are active at night and sit on foliage during the day. The elongated body and brown coloration of the adult serve as crypsis as they lie flat against a twig or branch. Larvae quickly burrow deep into the sand to avoid predation when the pit is disturbed by anything larger than a small prey item.

feeding ecology and diet

Adults are generalist predators, capturing prey on the wing. Larvae construct conical pits in fine, sandy soil by flicking sand out of the pit with rapid upward movements of the head. The larva waits at the bottom of the pit with only its large jaws exposed. When a suitable prey falls into the pit, the larva quickly seizes the prey by impaling it and injects paralyzing venom before dragging it below the sand surface.

reproductive biology

The adult female lays egg in sandy soil. Larvae burrow through the soil and form conical pits, typically under overhangs or in caves, to avoid precipitation that may disturb the pit and drown the larva. When development is complete, the larva spins a spherical cocoon from silk produced from the anus, which is impregnated with sand particles.

conservation status

Not threatened.

significance to humans

Antlion larvae, or "doodlebugs," have long been established in human folklore, particularly in children's chants or charms, typically from countries around the world that have been influenced by Europeans. Many charms referring to doodlebugs specifically cite the conical pits formed by the larva or their peculiar reverse-burrowing behavior.

Spoonwing lacewing

Nemoptera sinuata

family

Nemopteridae

taxonomy

Nemoptera sinuata Olivier, 1811, eastern Mediterranean.

other common names

None known.

physical characteristics

Large to medium-size lacewings. The body is elongate and robust, with relatively broad, rounded forewings. The hind wings are highly modified, narrow, and petiolate basally and slightly dilated apically, so that the wing is somewhat spoon-shaped. Wings are strikingly marked with irregular yellow and black banding. The forewings are held above the body, while the hind wings project posteriorly. The larvae are broad and oval shaped, with short necks and short jaws.

distribution

Europe and the Mediterranean region.

habitat

Open grasslands and forests.

behavior

Adults are active during the day, feeding at flowers.

feeding ecology and diet

Adults feed at flowers on pollen and nectar. Larvae lie buried in the sand, remaining inactive for long periods of time. When prey movement is detected, larvae approach slowly and attack with a single impaling of the prey with their jaws, during which time it is presumed that paralyzing venom is injected. Larvae are occasionally cannibalistic.

reproductive biology

Females lay eggs in sand. Larval development is prolonged and probably univoltine in nature. Adults are active in late spring.

conservation status

Not listed by the IUCN.

significance to humans

None known.

Norfolius

Norfolius howensis

family

Nymphidae

taxonomy

Myiodactylus howensis Tillyard, 1917, Lord Howe Island, New South Wales, Australia.

other common names

None known.

physical characteristics

Medium-size to large lacewings, with large, broad wings. Body is elongate and yellow-green in color, with a series of brown spots along the dorsal surface of thorax and abdomen. Antennae are long and yellow. Wings are transparent, with densely reticulate venation and black spots located on the pterostigma. Larva is discoid, with a quadrangular head and large, scythe-like jaws.

distribution

Eastern coastal regions of mainland Australia and Lord Howe Island (Australia).

habitat

Dense forested areas.

behavior

Nothing is known.

feeding ecology and diet

Adult and larva are generalist predators. Larva is a sedentary leaf litter dweller.

reproductive biology

Nothing is known.

conservation status

Not listed by the IUCN. Norfolius is not uncommon in densely forested (e.g., rainforest) areas along coastal eastern Australia. Habitat destruction appears to be the only real threat to this species.

significance to humans

None known.

Resources

Books

Aspöck, H., U. Aspöck, and H. Hölzel. Die Neuropteren Europas. 2 vols. Krefeld, Germany: Goecke and Evers, 1980.

McEwen, P. K., T. R. New, and A. E. Whittington, eds. Lacewings in the Crop Environment. Cambridge, U.K., and New York: Cambridge University Press, 2001.

New, T. R. "Planipennia (Lacewings)." In Handbuch der Zoologie: Eine Naturgeschichte der Stämme des Tierreiches. Vol. 4, Arthropoda: Insecta, edited by Max Beier, Maximilian Fischer, Johann-Gerhard Helmcke, Dietrich Starch, and Heinz Wermuth. Berlin and New York: W. de Gruyter, 1989.

——. "Neuroptera (Lacewings)." In The Insects of Australia, edited by CSRIO. 2nd edition. Vol. 1. Carlton, Australia: Melbourne University Press, 1991.

Periodicals

Aspöck, U. "Male Genital Sclerites of Neuropterida: An Attempt at Homologisation (Insecta: Holometabola)." Zoologischer Anzeiger 241, no. 2 (2002): 161–171.

Aspöck, U., J. D. Plant, and H. L. Nemeschkal. "Cladistic Analysis of Neuroptera and Their Systematic Position within the Neuropterida (Insecta: Holometabola: Neuropterida: Neuroptera)." Systematic Entomology 26 (2001): 73–86.

Oswald, J. D. "Revision and Cladistic Analysis of the World Genera of the Family Hemerobiidae (Insecta: Neuroptera)." Journal of the New York Entomological Society 101 (1993): 143–299.

Oswald, J. D., and N. D. Penny. "Genus-Group Names of the Neuroptera, Megaloptera and Raphidioptera of the World." Occasional Papers of the California Academy of Sciences 147 (1991): 1–94.

Withycombe, C. L. "Some Aspects of the Biology and Morphology of the Neuroptera, With Special Reference to the Immature Stages and Their Possible Phylogenetic Significance." Transactions of the Entomological Society of London (1924) 303–411.