Enicocephalomorpha
| Enicocephalomorpha | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||
|
||||||||||
| Scientific name | ||||||||||
| Enicocephalomorpha | ||||||||||
| Graver , 1955 |
The Enicocephalomorpha are a suborder of the bugs (Heteroptera).
The family group includes around 425 described species in 65 genera worldwide . Only one species, Henschiella pellucida , has been recorded in Europe and is only found in Bosnia and Herzegovina . Although the animals are rarely collected, it can be assumed that they are widespread in the temperate latitudes as well.
features
The animals are 2 to 15 millimeters long and have an elongated and relatively delicate physique. Her head is elongated and has mouthparts pointing forward. It is usually conspicuously constricted behind the compound eyes , the point eyes ( ocelli ), if present, being clearly separated from the compound eyes on the part in front of the constriction that is closer to the body. The gula (a sclerite on the underside of the head) is long and the short, straight to curved labium has four limbs. The forewings are always completely membranous, not modified to cover wings (Tegmina or Hemielytren ) as in most other bugs. The wing edge peripheral wing vein extends Remigium (the front portion of the wing membrane to the first fold) marginal (at the edge) or slightly submarginal (slightly offset from the edge). When the vein has receded, the course of the vein is at least traced by a continuous row of bristles (macrotrichia). The forewings are sometimes regressed or completely absent. On the forewings, the medial interruption of the vein lies in front of the radial vein, as otherwise only occurs in some species of Dipsocoromorpha . The base of the forewings carries a forked cross vein that connects the marginal veins with the radial vein and the medial vein + cubital vein.
The front legs are usually designed as catch legs. The splints ( tibia ) are elongated at the lower front (distoventral), usually widened and carry one or two groups of thorn-shaped bristles (setae). The opposite, ventral side of the single- or dual-segment Vordertarsen contribute as thorns.
The genitals of the males are symmetrical in all species and have genital plates arranged in pairs, as do the cicadas . In the Enicocephalidae they have regressed to a club-shaped "lead". The females sometimes have an ovipositor , sometimes they are missing. Unlike other bedbugs, it is not the seventh but the eighth sternum that forms the subgenital plate. A spermatheca is formed.
Sex dimorphism occurs between the males and females . In most species, the females are larger than the males and have smaller eyes and more stocky proportions, especially in the head and legs. The dimorphism is also very pronounced in the development of the wings, although depending on the species, a wide range of different wing development, regardless of gender, can be observed. In general, the species that are missing the wings or that only have receding wings have no ocelli and smaller compound eyes and their pronotum is modified. The trend is also clearly recognizable that these species tend to be wingless or have receding wings and that this feature occurs significantly more often in females than in males within a species.
Distribution and habitats
Almost all genera of the Enicocephalomorpha are limited in their distribution to the western or the eastern hemisphere. Only two genera deviate from this rule: Systelloderes is distributed almost worldwide from Canada to New Zealand and is only not found on some islands in the Palearctic , and Boreostolus is north-amphipacific (both on the Asian and American coasts of the Pacific) in front.
Both the nymphs and the adults basically live in the ground . Wherever there is sufficient moisture, it can be found in the top soil layers, where detritus accumulates. They are found numerous in the litter , under stones, or dead wood lying on the ground, under bark and at the base of suitable leaf sheaths . In leaf sheaths you can find Enicocephalus tupi in the substrate between the base of palm fronds and the stem of the plants. Boreostolus americanus lives under stones lying on the edge of rivers with a size of about 10 to 30 centimeters, in a moist, but not wet substrate made of small gravel and sand. How deep the representatives of the Enicocephalomorpha occur in the soil is not yet sufficiently known, but it can be assumed that they penetrate to considerable depths, as they are usually difficult to find, even if one knows that they are in the specific habitats in occur in large numbers. Species of the genus Alienates have been found in the nests of the American bush rat species Neotoma floridana and under moss cushions and liverworts . There are also species that live with ants ( myrmecophilia ). For example, Systelloderes angustatus from southern Brazil can be found in the nests of Camponotus rufipes .
Way of life
The females probably leave the ground to mate in the wetter months. They can store the males' sperm for at least two months after mating, and gradually lay fertilized eggs during that time. The representatives of the Enicocephalomorpha are the only bugs in which swarming behavior for mating occurs, similar to what is also the case, for example, with various groups of hymenoptera . The ratio of males and females in these swarmers differs depending on the species, but in most of them the number of males clearly predominates. Swarms can be observed late in the evening, especially in sunny, open areas near the edges of the forest or over open forest clearings. When swarming, the animals give off a clearly perceptible odor. The swarms can contain a single species of bug, but very often several species swarm together. The fully winged forms of many species can be attracted by artificial light sources at night. This mainly, but not only, affects their males. Wingless species are neither attracted by light, nor do they show swarming behavior. The Enicocephalomorpha predatorily feed on arthropods and are omnivorous . Presumably, however, the males no longer consume any food as adults.
In some species of Enicocephalomorpha, the behavior of shedding wings, which is unusual for bedbugs, occurs. This is otherwise only known to some representatives of the Gerridae and Aradidae within the bugs . In a few Enicocephalus -, very few Neoncylocotis -, some Oncylocotis and probably most Nesenicocephalus species, the females shed both pairs of wings. This happens after mating so that the females, who then retreat into the ground, can move around there better, as is the case with termites, for example .
Taxonomy and systematics
Earlier findings were based on a sister group relationship between the Enicocephalomorpha and all other groups of bugs or a close relationship with the predatory bugs (Reduviidae). A multigene study from 2012 not only confirmed the monophyly of the seven partial orders of the bedbugs due to molecular phylogeny, it also showed that the Enicocephalomorpha is probably closely related to the partial order of the Leptopodomorpha .
The following families are included in the partial order:
Individual evidence
- ^ Family Enicocephalidae. Australian Biological Resources Study. Australian Faunal Directory, accessed October 24, 2013 .
- ↑ a b c d e f g R.T. Schuh, JA Slater: True Bugs of the World (Hemiptera: Heteroptera). Classification and Natural History. Cornell University Press, Ithaca, New York, 1995.
- ↑ Enicocephalomorpha. Fauna Europaea, accessed October 18, 2013 .
- ^ A b c d Pedro W. Wygodzinsky, Kathleen Schmidt: Revision of the New World Enicocephalomorpha (Heteroptera). Bulletin of the American Museum of Natural History 200, 1991, pp. 1-265.
- ↑ P. Štys: Zoogeography of Enicocephalomorpha (Heteroptera). Bulletin of insectology, 61 (1): 137-138, 2008. online: PDF
- ↑ Min Li, Ying Tian, Ying Zhao, Wenjun Bu (2012): Higher Level Phylogeny and the First Divergence Time Estimation of Heteroptera (Insecta: Hemiptera) Based on Multiple Genes. PLoS ONE 7 (2): e32152. doi : 10.1371 / journal.pone.0032152 (open access)
literature
- RT Schuh, JA Slater: True Bugs of the World (Hemiptera: Heteroptera). Classification and Natural History. Cornell University Press, Ithaca, New York, 1995.