Megaloptera

Megaloptera is an order of insects. It contains the alderflies, dobsonflies and fishflies, and there are about 300 known species.

The order's name comes from Ancient Greek, from mega- (μέγα-) "large" + pteryx (πτέρυξ) "wing", in reference to the large, clumsy wings of these insects. Megaloptera are relatively unknown insects across much of their range, due to the adults' short lives, the aquatic larvae's often-high tolerance of pollution (so they are not often encountered by swimmers etc.), and the generally crepuscular or nocturnal habits. However, in the Americas the dobsonflies are rather well-known, as their males have tusk-like mandibles. These, while formidable in appearance, are relatively harmless to humans and other animals; much like a peacock's feathers, they serve mainly to impress females. However, the mandibles are also used to hold females during mating, and some male dobsonflies spar with each other in courtship displays, trying to flip each other over with their long mandibles. Dobsonfly larvae, commonly called hellgrammites, are often used for angling bait in North America.

The Megaloptera were formerly considered part of a group then called Neuroptera, together with lacewings and snakeflies, but these are now generally considered to be separate orders, with Neuroptera referring to the lacewings and relatives (which were formerly called Planipennia). The former Neuroptera, particularly the lacewing group, are nonetheless very closely related to each other, and the new name for this group is Neuropterida.[1] This is either placed at superorder rank, with the Endopterygota—of which they are part—becoming an unranked clade above it, or the Endopterygota are maintained as a superorder, with an unranked Neuropterida being a part of them. Within the endopterygotes, the closest living relatives of the neuropteridan clade are the beetles.

The Asian dobsonfly Acanthacorydalis fruhstorferi can have a wingspan of up to 21.6 cm (8.5 in), making it the largest aquatic insect in the world by this measurement.[2][3]

Megaloptera
Temporal range: Permian–Recent
Sialis spPCCA20050708-9036A
Alderfly of the genus Sialis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
(unranked): Endopterygota
Order: Megaloptera
Latreille, 1802
Families

Corydalidae
Sialidae
and see text

Corydalus cornutus MHNT male
Corydalus cornutus - MHNT

Anatomy and life cycle

Adult megalopterans closely resemble the lacewings, except for the presence of a pleated region on their hind wings, helping them to fold over the abdomen. They have strong mandibles and mouthparts apparently adapted for chewing, although many species do not eat as adults. They have large compound eyes, and, in some species, also have ocelli. The wings are large and subequal.[4]

The female may lay up to 3,000 eggs in a single mass, placing them on vegetation overhanging water. Megaloptera undergo the most rudimentary form of complete metamorphosis among the insects. There are fewer differences between the larval and adult forms of Megaloptera than in any other order of holometabolous insects, and their aquatic larvae dwell in fresh water, around which the adults also live. The larvae are carnivorous, and are known to feed on small invertebrates, such as crustaceans, clams, worms and other insects. They possess strong jaws that they use to capture their prey. They have large heads and elongated bodies. The abdomen bears a number of fine tactile filaments, which, in some species, may include gills. The final segment of the abdomen bears either a pair of prolegs, or a single, tail-like appendage.[4]

The larvae grow slowly, taking anywhere from 1 to 5 years to reach the last larval stage. When they reach maturity, the larvae crawl out onto land to pupate in damp soil or under logs. Unusually, the pupa is fully motile, with large mandibles that it can use to defend itself against predators. The short-lived adults emerge from the pupa to mate - many species never feed as adults, living only a few days or hours.[4]

Evolution

Apart from the two living families, there are a few prehistoric taxa in the Megaloptera, only known from fossils. Some of these occupy a more basal position:[5]

  • Genus Corydasialis (sometimes considered monotypic family Corydasialidae[6])
  • Family Parasialidae (probably paraphyletic)
  • Family Euchauliodidae
  • Family Nanosialidae[7]

The Megaloptera are monophyletic and are a sister clade of the Neuroptera.[8] Within the Megaloptera, Corydalinae and Chauliodinae are sister clades. The divergence time estimation suggests that the stem lineage of Neuropterida and Coleoptera separated in the Early Permian

Footnotes

  1. ^ Also called "Neuropteroidea", though the ending "-oidea" is normally used for superfamilies. See references in Haaramo (2008).
  2. ^ "Largest aquatic insect (by wingspan)". Guinness World Records. Retrieved 4 April 2018.
  3. ^ Jonathan O'Callaghan (24 July 2014). "The stuff of nightmares! New species of insect discovered in China - and it has a wingspan of more than EIGHT INCHES". Daily Mail. Retrieved 26 July 2014.
  4. ^ a b c Hoell, H.V., Doyen, J.T. & Purcell, A.H. (1998). Introduction to Insect Biology and Diversity, 2nd ed. Oxford University Press. pp. 441–443. ISBN 0-19-510033-6.CS1 maint: Multiple names: authors list (link)
  5. ^ See references in Haaramo (2008)
  6. ^ Engel & Grimaldi (2007)
  7. ^ Shcherbakov DE (2013) Permian ancestors of Hymenoptera and Raphidioptera. ZooKeys 358: 45–67. doi: 10.3897/zookeys.358.6289
  8. ^ Wang Y, Liu X, Winterton SL, Yang D (2012) The first mitochondrial genome for the fishfly subfamily Chauliodinae and implications for the higher phylogeny of Megaloptera. PLoS One 7(10):e47302. doi: 10.1371/journal.pone.0047302

References

Data related to Megaloptera at Wikispecies

Alderfly

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 altogether – are part of the subfamily Sialinae, which contains between one and seven extant genera according to different scientists' views.

Corydalidae

The family Corydalidae contains the megalopterous insects known as dobsonflies and fishflies. Making up about one dozen genera, they occur primarily throughout the Northern Hemisphere, both temperate and tropical, and South America.

They are sizeable Megaloptera, with a body usually larger than 25 mm (1 inch). They often have long filamentous antennae, though in male fishflies they are characteristically feathered. Ocelli are present; the fourth tarsal segment is cylinder-shaped. The four large wings are translucent, smoky grey, or mixed, and the anterior pair is slightly longer than the posterior one.

The eastern dobsonfly, Corydalus cornutus, is the most well-known North American species among the dobsonflies. These genera have distinctive elongated mandibles in males and form the subfamily Corydalinae. The genera in which the males have normal mandibles, called fishflies, form the subfamily Chauliodinae. The summer fishfly, Chauliodes pectinicornis, is perhaps the best-known of these in North America; its immense mating swarms in the Upper Mississippi River region fill the air on a few summer nights each year much like mayflies in certain regions of Europe, leaving millions of carcasses to be cleaned up the next day.

The larvae are aquatic, active, armed with strong sharp mandibles, and breathe by means of abdominal branchial filaments. When full sized — which can take several years — they leave the water and spend a quiescent pupal stage on the land, in chambers dug under stones or logs, before metamorphosis into the sexually mature insect.

Dicondylia

The Dicondylia are a taxonomic group (taxon) that includes all insects except the jumping bristletails (Archaeognatha). Dicondylia have a mandible attached with two hinges to the head capsule (dicondyl), in contrast to the original mandible with a single ball joint (monocondyl).

Dobsonfly

Dobsonflies are a subfamily of insects, Corydalinae, part of the Megalopteran family Corydalidae. The larvae (commonly called hellgrammites) 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.

Endopterygota

Endopterygota (from Ancient Greek endon “inner” + pterón, “wing” + New Latin -ota “having”), also known as Holometabola, 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.

The Endopterygota are among the most diverse insect superorders, with over 1 million living species divided between 11 orders, containing insects such as butterflies, flies, fleas, bees, ants, and beetles.They are distinguished from the Exopterygota (or Hemipterodea) by the way in which their wings develop. Endopterygota (meaning literally "internal winged forms") develop wings inside the body and undergo an elaborate metamorphosis involving a pupal stage. Exopterygota ("external winged forms") develop wings on the outside their bodies and do not go through a pupal stage. The latter trait is plesiomorphic, however, and not exclusively found in the exopterygotes, but also in groups such as Odonata (dragonflies and damselflies), which are not Neoptera, but more basal among insects.

The earliest endopterygote fossils date from the Carboniferous.

Eumetabola

Eumetabola is an unranked category of Neoptera. Two large unities known as the Paurometabola and Eumetabola are probably from the adelphotaxa of the Neoptera after exclusion of the Plecoptera. The monophyly of these unities appears to be weakly justified.

Fishfly

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 (especially in males) 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.

Fishflies lay their eggs upon vegetation overhanging streams, whence the larvae, as soon as hatched, drop into the water, and go about preying upon aquatic animals. When ready to transform to pupae, they crawl out upon the bank and are then found in cavities under stones or even under the bark of trees.In contrast to mayflies, which are small and usually live for a day or less as adults, fishflies are quite large, with a wingspan of 2.5 to 3 inches (6 to 8 cm). They will eat aquatic plants as well as small animals including vertebrates like minnows and tadpoles, and may live up to seven days as adults. Their entire lifespan is several years, but most of this time is spent as larvae.

Ilisha megaloptera

The bigeye ilisha (Ilisha megaloptera) is a species of ray-finned fish in the family Pristigasteridae. It occurs in the tropical Indo-Pacific region, in coastal waters, estuaries and the tidal parts of rivers.

Megaloptera (moth)

Megaloptera is a genus of moths of the family Noctuidae.

Nathan Banks

Nathan Banks (April 13, 1868 – January 24, 1953) was an American entomologist noted for his work on Neuroptera, Megaloptera, Hymenoptera, and Acarina (mites). He started work on mites in 1880 with the USDA. In 1915 he authored the first comprehensive English handbook on mites: A Treatise on the Acarina, Or Mites (Smithsonian Institution, Proceedings Of The United States National Museum, 1905, 114 pages).

Banks left the USDA in 1916 to work at the Museum of Comparative Zoology (MCZ) where he did further work on Hymenoptera, Arachnida and Neuroptera. He was elected a Fellow of the American Academy of Arts and Sciences in 1922.In 1924, he spent about two months in Panama, through kindness of Dr. Thomas Barbour and in company with Dr. W.M. Wheeler. Between mid June and mid August they divided time between forested regions on Barro Colorado Island and more open habitat at various points along the railroad in the vicinity of Panama City (See Banks, 1929 "Spiders of Panama" for details).

He authored more than 440 technical works over the years 1890 to 1951. He was married to Mary A. Lu Gar and they had eight children. (One son was named Gilbert, but no other offspring are known by name.)

Neohermes

Neohermes is a genus of fishflies in the family Corydalidae. There are about 5 described species in Neohermes.

Neuroptera

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 can be grouped together with the Megaloptera and Raphidioptera in the superfamily Neuropterida (once known as Planipennia) including: alderflies, fishflies, dobsonflies, and snakeflies.

Adult Neuropterans have four membranous wings, all about the same size, with many veins. They have chewing mouthparts, and undergo complete metamorphosis.

Neuropterans first appeared during the Permian Period, and continued to diversify through the Mesozoic Era. During this time, several unusually large forms evolved, especially in the extinct family Kalligrammatidae, often referred to as "the butterflies of the Jurassic" due to their large, patterned wings.

Neuropterida

The Neuropterida are a clade, sometimes placed at superorder level, of holometabolous insects with over 5,700 described species, containing the orders Neuroptera (lacewings, antlions), Megaloptera (alderflies, dobsonflies), and Raphidioptera (snakeflies).

Historically, they were known as Neuroptera, but this name nowadays refers to lacewings and their relatives (e.g. antlions) only, which formerly were known as Planipennia. Part of the Endopterygota and related to beetles, they can be considered an unranked taxon. Arguably, the Endopterygota might be considered an unranked clade instead, and be split up in numerous superorders to signify the close relationships of certain endopterygote groups.The Mecoptera (scorpionflies) were formerly included here too by some authors, but they actually belong to the Mecopteroidea (or Antliophora), the endopterygote clade containing also true flies and fleas.

Neuropterida are fairly primitive-looking insects, with large wings but weak wing muscles, giving them a clumsy flight. Most are active at dusk or in the night as adults, and the larvae of many are aquatic, living in rivers. At least the larvae, but in many cases the adults too, are predators of small arthropods. Adult neuropteridans range in size from that of a midge to that of a large dragonfly (15 cm wingspan); the largest species tend to resemble drab, clumsily flying damselflies.

In addition to the three living orders, there is an entirely extinct family of Neuropterida, the monotypic Rafaelidae. These are of an indeterminate but probably rather basal position; thus the single genus Rafaelia from the Early Cretaceous Santana Formation's Crato Member in Brazil might for the time being be better placed in the Neuropterida directly, without assigning it to an order, until relatives are found and/or its systematic position gets resolved better. The extinct order Glosselytrodea may also be a member or close relative, though classification is unclear.

Protosialis casca

Protosialis casca is an extinct species of alderfly in the Sialidae subfamily Sialinae. The species is solely known from the early Miocene, Burdigalian stage, Dominican amber deposits on the island of Hispaniola. Protosialis casca is one of only two known alderfly species present in the West Indies, the only other species is the living Protosialis bifasciata native to Cuba.

Pterygota

The Pterygota are a subclass of insects that includes the winged insects. It also includes insect orders that are secondarily wingless (that is, insect groups whose ancestors once had wings but that have lost them as a result of subsequent evolution).The pterygotan group comprises almost all insects. The insect orders not included are the Archaeognatha (jumping bristletails) and the Zygentoma (silverfishes and firebrats), two primitively wingless insect orders. Also not included are the three orders no longer considered to be insects: Protura, Collembola, and Diplura.

Sialis

Sialis is a genus of alderfly belonging to the order Megaloptera family Sialidae.

Sialis lutaria

Sialis lutaria, common name alderfly, is a species of alderfly belonging to the order Megaloptera family Sialidae.

Snakefly

Snakeflies are a group of insects comprising the order Raphidioptera, which is divided into two families: Raphidiidae and Inocelliidae consisting of roughly 260 species. Together with the Megaloptera they were formerly placed within the Neuroptera, but now these two are generally regarded as separate orders. Members of this order have been considered living fossils, as the phenotype of a species from the early Jurassic period (140 million years ago) closely resembles modern-day species.

Stackhousia

Stackhousia is a genus of annual and perennial plants in the family Celastraceae that are native to Australia, New Zealand, Malesia and Micronesia. The genus was first described by James Edward Smith in Transactions of the Linnean Society of London in 1798.

It was formerly placed in Stackhousiaceae, but under the APG II system this family has been folded into Celastraceae.

Species include:

Stackhousia annua W.R.Barker

Stackhousia aspericocca Schuch.

Stackhousia clementii Domin

Stackhousia dielsii Pamp. - Yellow stackhousia

Stackhousia gunnii Hook.f. now Stackhousia subterranea

Stackhousia huegelii Endl.

Stackhousia intermedia F.M.Bailey

Stackhousia megaloptera F.Muell.

Stackhousia minima Hook.f.

Stackhousia monogyna Labill. - Creamy candles, creamy stackhousia

Stackhousia muricata Lindl.

Stackhousia pubescens A.Rich. - Downy stackhousia

Stackhousia pulvinaris F.Muell. - Alpine stackhousia

Stackhousia scoparia Benth.

Stackhousia spathulata Sieber ex Spreng.

Stackhousia stratfordiae W.R.Barker & Cockerton

Stackhousia subterranea W.R.Barker - Gunn's mignonette, grasslands candles

Stackhousia tryonii F.M.Bailey

Stackhousia umbellata C.A.Gardner & A.S.George

Stackhousia viminea Sm. - Slender stackhousia

Insect orders
Extant Megaloptera families

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