The insect order Zoraptera, commonly known as angel insects, contains a single family, the Zorotypidae, which in turn contains one extant genus Zorotypus with 44 extant species and 11 species known from fossils. They are small and soft bodied insects with two forms: winged with wings sheddable as in termites, dark and with eyes (compound) and ocelli (simple); or wingless, pale and without eyes or ocelli. They have a characteristic nine segmented beaded (moniliform) antenna. They have mouthparts adapted for chewing and are mostly found under bark, in dry wood or in leaf litter.
The name Zoraptera, given by Filippo Silvestri in 1913, is misnamed and potentially misleading: "zor" is Greek for pure and "aptera" means wingless. "Pure wingless" clearly does not fit the winged alate forms, which were discovered several years after the wingless forms had been described.
The members of this order are small insects, 3 millimetres (0.12 in) or less in length, that resemble termites in appearance and in their gregarious behavior. They are short and swollen in appearance. They belong to the hemimetabolous insects. They possess mandibulated biting mouthparts, short cerci (usually 1 segment only), and short antennae with 9 segments. The abdomen is segmented in 11 sections. The maxillary palps have five segments, labial palps three, in both the most distal segment is enlarged. Immature nymphs resemble small adults. Each species shows polymorphism. Most individuals are the apterous form or "morph", with no wings, no eyes, and no or little pigmentation. A few females and even fewer males are in the alate form with relatively large membranous wings that can be shed at a basal fracture line. Alates also have compound eyes and ocelli, and more pigmentation. This polymorphism can be observed already as two forms of nymphs. Wingspan can be up to 7 millimetres (0.28 in), and the wings can be shed spontaneously. When observed, wings have simple venation. Under good conditions the blind and wingless form predominates, but if their surroundings become too tough, they produce offspring which develop into winged adults with eyes. The wings are paddle shaped, and have reduced venation.
The phylogenetic relationship of the order remains controversial and elusive. At present the best supported position based on morphological traits recognizes the Zoraptera as polyneopterous insects related to the webspinners of the order Embioptera. However, molecular analysis of 18s ribosomal DNA supports a close relationship with the superorder Dictyoptera.
They live in small colonies beneath rotting wood, lacking in mouthparts able to tunnel into sound wood, eating fungal spores and detritus but also can hunt smaller arthropods like mites and collembola.
Zorotypus gurneyi lives in colonies consisting of up to several hundred of individuals. Most commonly the colonies have a size of around 30 individuals, of which about 30% are nymphs, the remainder adults. Zoraptera spend most of their time grooming one another. The grooming process is thought to be a way of removing fungal pathogens.
When two colonies of Z. hubbardi are brought together experimentally, there is no difference in behavior towards members of the own or new colony. Therefore, colonies in the wild might merge easily. Winged forms are rare. The males in such average colonies establish a linear dominance hierarchy in which age or duration of colony membership is the prime factor determining dominance. Males appearing later in colonies are at the bottom of the hierarchical ladder, regardless of their body size. By continually attacking other males, the dominant male monopolizes a harem of females. The members of this harem stay clumped together. There is a high correlation between rank and reproductive success of the males.
Z. barberi lack such a dominance structure but display complex courtship behavior including nuptial feeding. The males possess a cephalic gland that opens in the middle of their head. During courtship they secrete a fluid from this gland and offer it to the female. Acceptance of this droplet by the female acts as behavioral releaser and immediately leads to copulation.
In Z. impolitus, copulation does not occur, but fertilization is accomplished instead by transfer of a spermatophore from the male to the female. This 0.1-millimetre (0.0039 in) spermatophore contains a single giant sperm cell, which unravels to about the same length as the female herself, 3 millimetres (0.12 in). It is thought that this large sperm cell prevents fertilization by other males, by physically blocking the female's genital tract.
Zoraptera are thought to provide some important supporting and provisioning services in ecosystems. By consuming detritus, such as dead arthropods, they assist in decomposition and nutrient cycling.
55 living and fossil species are found worldwide, mainly in tropical and subtropical regions around the world. Four species occur north of the Tropic of Cancer, two in the United States and two in Tibet.
The cheval tree is native to North Island, part of the Agaléga Islands, a territory of Mauritius. It is unique in its properties of minor adhesivity, which attracts insects: specifically, heelwalkers (belonging to the Mantophasmatodea) or Formosozoros newi (belonging to the Zoraptera). The tree was named for the glue-like secretion of its bark and the use of horse-hooves for glue in former times—the French word (French is the colonizing language of Agalega) for "horse" is "cheval".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).Embioptera
The order Embioptera, commonly known as webspinners, are a small group of mostly tropical and subtropical insects, classified under the subclass Pterygota. The order has also been referred to as Embiodea or Embiidina. The name Embioptera ("lively wings") comes from Greek, εμβιος, embios meaning "lively" and πτερον, pteron meaning "wing", a name that has not been considered to be particularly descriptive for this group of fliers, perhaps instead referring to their remarkable speed of movement both forward and backward. The group probably first appeared during the Jurassic and is well represented in Cretaceous amber. The common name webspinner comes from the insects' unique ability to spin silk from structures on their front legs. They use the silk to make a web-like pouch or gallery in which they live.
Over 360 embiopteran species have been described, along with estimates of around 2000 species being in existence today. There is some debate as to the exact phylogenetic classification of Embioptera, with the order having been classed as a sister group to both orders Zoraptera, and Phasmatodea, and there is continuing dispute today concerning the accuracy of these classifications.The order is distributed all over the world, being found on every continent except Antarctica, with the highest density and diversity of species being located in tropical regions.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.Exopterygota
The Exopterygota, also known as Hemipterodea, are a superorder of insects of the subclass Pterygota in the infraclass Neoptera, in which the young resemble adults but have externally developing wings. They undergo a modest change between immature and adult, without going through a pupal stage. The nymphs develop gradually into adults through a process of moulting.
The Exopterygota are a highly diverse insect superorder, with at least 130,000 living species divided between 15 orders. They include cockroaches, termites, grasshoppers, thrips, lice and stick insects, among many other types of insects.
They are distinguished from the Endopterygota (or Holometabola) 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 of their bodies without going through a true pupal stage, though a few have something resembling a pupa (e.g., Aleyrodidae).
Ephemeroptera (mayflies) and Odonata (dragonflies and damselflies) also have gradual wing development, this being a plesiomorphic trait. These two orders belong to the infraclass Palaeoptera however, which is not included in Neoptera. As opposed to Neoptera, they cannot fold their wings over their back in the horizontal plane, only vertically (as damselflies do) if at all.Filippo Silvestri
Filippo Silvestri (22 June 1873 – 10 June 1949) was an Italian entomologist. He specialised in world Protura, Thysanura, Diplura and Isoptera, but also worked on Hymenoptera, Myriapoda and Italian Diptera. He is also noted for describing and naming the previously unknown order Zoraptera. In 1938 he was nominated to the Pontifical Academy of Sciences, the scientific academy of the Vatican.Silvestri was born in Bevagna. A keen young naturalist, he became assistant to Giovanni Battista Grassi (1854–1925), Director of the Institute of Anatomical Research of the University of Rome. In 1904, Silvestri became Director of the Institute of Entomology and Zoology at the agricultural college in Portici (the Laboratorio di Zoologia Generale e Agraria, now Faculty of Agriculture), a position he held for 45 years.
He discovered polyembryony in the 1930s while working on Litomatix truncatellus Hymenoptera.
His collection is in the Museo Civico di Storia Naturale di Genova. Duplicates of Isoptera are
in the Swedish Museum of Natural History and a few Diplopoda (millipede) types are in the Museum für Naturkunde Berlin.
Filippo Sivestri has been commemorated in the names of the following: a square in his home town, Bevagna; a high school in Portici, the town where he worked and died; and a street in Rome (00134 Borgo Lotti).
A species of South American worm lizard, Amphisbaena silvestrii is named in his honor.Publications on termites.
Nota preliminare sui termitidi sud-americani. Bollettino dei Musei di Zoologia e Anatomia Comparata della Università di Torino XVI(389):1-8.( 1901)
Contribuzione alla conoscenza dei Termiti e Termitofili dell'America Meridionale. Redia 1:1-234. .( 1903)
Isoptera. In: Die Fauna Südwest-Australia. Vol. 2, edited by W. Michaelsen & R. Hartmeyer. pp. 279–314. .( 1909)
Contribuzione alla conoscenza dei Termitidi e Termitofili dell'Africa occidentale. Bollettino del Laboratorio di Zoologia General e Agraria, Portici 9:1-146. .( 1914)
Descriptiones termitum in Anglorum Guiana. Zoologica 3(16):307-321. .( 1923)
Descrizioni di due nuove specie di Isoptera dell'Africa. Bollettino del Laboratorio di Zoologia Generale e Agraria, Portici 21:91-95. .( 1928)
Nuovo concetto di fasi corrispondenti all'età della colonia negli individui di una stessa specie componenti una colonia di termiti e descrizione di due specie nuove di Syntermes. Bollettino del Laboratorio di Entomologia Agraria, Portici 6:1-14 (1946).Translated from Wikipedia FranceNeoptera
Neoptera is a classification group that includes most orders of the winged insects, specifically those that can flex their wings over their abdomens. This is in contrast with the more basal orders of winged insects (the "Palaeoptera" assemblage), which are unable to flex their wings in this way.Orthopterida
The Orthopterida is a superorder of the Polyneoptera that represents the extant orders Orthoptera (grasshoppers, crickets, and katydids), and Phasmatodea (stick insects and leaf insects). The Orthopterida also includes the extinct orders Titanoptera and Caloneurodea. There is general consensus of monophyly in this superorder, based on reduction of the second valvulae, an ovipositor derived from the gonoplac, and an enlarged precostal region on the forewing.
The two other superorders of the Polyneoptera are the Plecopterida, which represents the orders Plecoptera (stoneflies), Emboidea (Embioptera/Embiidina; webspinners), and Zoraptera (angel insects), and the Dictyoptera, which represents Blattodea (cockroaches & termites), and Mantodea (mantids). Two other orders, the Notoptera (ice-crawlers and gladiators) and Dermaptera (earwigs) are also placed in the Polyneoptera but outside the superorders discussed above.Palaeoptera
The name Palaeoptera has been traditionally applied to those ancestral groups of winged insects (most of them extinct) that lacked the ability to fold the wings back over the abdomen as characterizes the Neoptera. The Diaphanopterodea, which are palaeopteran insects, had independently and uniquely evolved a different wing-folding mechanism. Both mayflies and dragonflies lack any of the smell centers in their brain found in Neoptera.Panorpida
Panorpida or Mecopterida is a proposed superorder of Endopterygota. The conjectured monophyly of the Panorpida is historically based on morphological evidence, namely the reduction or loss of the ovipositor and several internal characteristics, including a muscle connecting a pleuron and the first axillary sclerite at the base of the wing, various features of the larval maxilla and labium, and basal fusion of CuP and A1 veins in the hind wings. The monophyly of the Panorpida is also supported by recent molecular data.Polyneoptera
The cohort Polyneoptera is probably the most appropriate taxonomic ranking for commonly-used terms such as Orthopteroid insects: namely the orders similar to the Orthoptera (grasshoppers, crickets, etc.). They are all winged insects (Pterygota), derived from ancestors that evolved to fold their wings (Neoptera) and possess biting mouthparts, but undergo little or no metamorphosis.Protodiptera
Protodiptera is an extinct order of insects containing the two genera Permotipula and Permila.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.Zorotypus absonus
Zorotypus absonus is an extinct species of insect in the order Zoraptera. It was discovered by Engel in 2008 and it lived in the Miocene.Zorotypus amazonensis
Zorotypus amazonensis is a species of insect in the genus Zorotypus. It is found in the central Amazonia. Males possess features that distinguish them from related species. The male cerci is elongated, curved, and studded with three stiff setae along inner margins allowing for a "clasperlike" appearance.Zorotypus cervicornis
Zorotypus cervicornis is a species of insect in the order Zoraptera. It was first found in Malaysia.Zorotypus hubbardi
Zorotypus hubbardi, commonly known as Hubbard's angel insect, is a species of insect in the order Zoraptera. It is native to the tropical and subtropical New World and has expanded its range into the eastern United States, where it lives in piles of sawdust, whereas in the hotter part of its range it lives under the bark of decomposing logs. It was named after the American entomologist Henry Guernsey Hubbard, who discovered the insect in the United States.Zorotypus impolitus
Zorotypus impolitus is a species of insect in the order Zoraptera.Zorotypus magnicaudelli
Zorotypus magnicaudelli is species of insect in the order Zoraptera. It was first found in Malaysia.