Nemonychidae

from Wikipedia, the free encyclopedia
Nemonychidae
Doydirhynchus austriacus

Doydirhynchus austriacus

Systematics
Class : Insects (Insecta)
Order : Beetle (Coleoptera)
Subordination : Polyphaga
Partial order : Cucujiformia
Superfamily : Curculionoidea
Family : Nemonychidae
Scientific name
Nemonychidae
Bedel , 1882

The Nemonychidae are a family of weevils (in the broader sense, superfamily Curculionoidea ). Almost all of the oldest fossil weevils from the Jura belong to this family. The species living today form a species-poor relic group, they are considered to be the most original weevils still alive. The family includes 75 living (recent) species in 25 genera and at least 56 known fossil species. There are three species living in Central Europe.

features

The family includes quite small, inconspicuous, yellow-brown to black colored beetles with a relatively uniform body shape. As a rule, they are elongated animals with parallel-sided wing-coverts, a laterally slightly rounded pronotum that is slightly narrower than the wing-coverts and a protruding head with hemispherical complex eyes protruding from the head contour. Compared to other Curculionoidea, the animals are delicately built and slightly sclerotized. Almost all species have thick, fine hairs that are often white in color. Dandruff or dandruff, which is characteristic of numerous families of weevils, does not occur. The proboscis (or rostrum) that gives the weevil its name is modified in many ways, there are species with a very short, others with a long and thin, curved proboscis, and sometimes the proboscis is somewhat widened (widened) towards the tip. The feelers can also be deflected at the base, in the middle or near the tip of the trunk. As a major exception among the weevils (outside of the bark beetles in the broader sense ) there is even a species in the family without a proboscis: Brarus mystus from Brazil, which at first glance can therefore be confused with a gloss beetle .

The Nemonychidae belong to the more original grouping of weevils with straight, non-kneeled antennae ("Orthoceri"), the eleven-membered antennae have a loosely separated, loosely structured, three-membered antennae. The family also has numerous other ancient plesiomorphic features that distinguish them within the weevils. The labrum is not fused with the clypeus, but is freely formed. The maxillary palps are multi-limbed and mobile. In contrast to most of the other lines of the weevils (only together with the Belidae and some Attelabidae ) the elytra or elytra have no inner edge; as a result, it is not possible for them, like the representatives of the other lineages, to couple the elytra firmly to the abdomen and thus assume a well-protected, armored form of protection. The abdomen is accordingly loosely structured, the sclerites on the abdomen are not fused together for better protection. The most important autapomorphy is the shape of the ninth tergite on the abdomen of the male. This is transformed into an unsclerotized, but strongly pigmented band, which rests on the ninth sternite.

Larvae

The larvae of the Nemonychidae are small, less than ten millimeters long and slender animals. Just like the adults, the larvae also have numerous original, plesiomorphic features that distinguish the family from the other lines of weevils. Larvae with three or four-limbed legs with a claw at the end are only found in the genus Nemonyx , while typical weevil larvae are legless. The larva has a single functional larval eye (stemma or ocularium) and dysfunctional rudiments of two or three others.

The peculiar features (autapomorphies) of the nemonychid larvae are: The seam between the clypeus and the fron on the head capsule has disappeared, the fron is extended forward and forms a so-called pseudoclypeus. There is also a characteristic chewing bar on the basal part of the mandibles, in the area of ​​the chewing surface or mola. A striking peculiarity of the larvae of the subfamily Rhinorhynchinae is that on a flat surface they crawl not with the belly side, but with the back side down.

Way of life

With two exceptions, Nemonychidae are tied to conifers . The larvae are specialized pollen-eaters, they live in the strobili , the male, cone-like "flower catkins" that produce the large amounts of pollen typical of the wind-flowering conifers. The female usually lays her egg on the pollen sacs (or microsporangia) in the strobili when these begin to open but the pollen grains are still immature. The female ovipositor is soft and unsclerotized and unable to pierce hard tissue. The larvae eat the pollen grains, they are very mobile and may switch back and forth between different male kittens. Due to the very nutrient-rich food, the larval development is extremely rapid, all larval stages are typically completed in ten days (rarely in two or three weeks). The mature larva drops to the ground and digs a small pupa chamber right under the leaf litter.

The further development of many species is complex. Some of the larvae can pupate immediately and then hatch after about three weeks of pupal rest. These adults hibernate and are active for eight months or more. You need to ingest food during this time. As far as is known, the adults of all species either feed on pollen or on sweet vegetable juices. Eating of the leaves or needles of their host species was not observed in any case. Another part of the larvae remain in the pupa chamber and overwinter in the ground. They come outside after one, in some cases sometimes only after two years, exactly when the immediately transformed adults hatch. This behavior is interpreted as an insurance against unfavorable, low-nutrient years.

Almost all Nemonychidae are very host-specific on a conifer genus, very often only on one species. The species of the subfamily Cimberidinae, which are distributed in the northern hemisphere ( Palearctic and Nearctic ), live on pines , all Central European (Western Palearctic ) species on pines (genus Pinus ). The Rhinorhynchinae living in South America as well as in Western Australia and New Guinea occur on araucarias ( araucarias and kauri trees , not on wollemia ) and stone bees , the genus Atopomacer , which occurs in central and North America, has passed, probably secondarily, to pinus .

As an exception in the family, there are two kin groups who live on angiosperms . All species of the subfamily Nemonychinae are specialists in the field delphiniums (genus Consolida ), a kind of delphiniums ( Delphinium ), both to the buttercups are. The two related genera Rhynchitomacer and Stenomacer live on false beeches (genus Nothofagus , Fagales ); but only in South America, although the genus occurs in Australia and the surrounding islands and is even more species-rich here. All species are monophagous on a single Nothofagus species, although usually several of these occur together in a forest. Both the beech-like and the buttercups belong to the basal lines of the angiosperms.

Taxonomy and systematics

The family taxonomy is confused. The name Rhinomaceridae, which was often used in the past, is invalid because the name of the type genus was given several times and for two genera that were not closely related. In its later meaning it goes back to Fabricius. The type species of its genus Rhinomacer has, however, been described earlier with a different generic name. The later entomologists worsened the chaos with their interpretations of this situation and created several illegitimate substitute names. The family name Nemonychidae, actually younger than the name "Cimberididae" , has been submitted to the International Commission on Zoological Nomenclature as a name to be preserved in the interests of nomenclature stability.

The majority of scientists consider the Anthribidae family (or weevils) to be a sister group of the Nemonychidae. Earlier entomologists even considered them to be a subfamily of the Anthribidae. It still seems possible today that the Nemonychidae are to be found within the Anthribidae, so that these would be paraphyletic towards them. Another possibility would be that the Nemonychidae were isolated and a sister group of the remaining weevils put together. An important difference between Nemonychidae and Anthribidae is the formation of the legs. In the Nemonychidae, these have spurs on the rails (tibiae) that the Anthribidae lack.

The recent Nemonychidae are usually divided into three subfamilies:

Fossils and Evolution

The oldest fossil Nemonychidae come from the Jurassic , they are among the oldest fossil weevils. Most of them were found in the Karatau fossil deposit (today's spelling Qaratau ) in Kazakhstan. Other finds are from the Santana Formation in Brazil and the Jehol Biota from China. While there are still some finds in the chalk, until recently no more find was known from the Tertiary, until at least one species was described in Baltic amber in 2010.

The assignment of numerous fossil weevils is still controversial today. Since the family Nemonychidae is mainly characterized by plesiomorphic features and the few autapomorphies can hardly be preserved in fossil form, the assignment is more speculative, the older the fossils get. It is quite likely that the superfamily descended from forms that may have looked extremely similar to the recent Nemonychidae. Particularly controversial is a group of forms or relationships known as Eobelinae (or Eobelidae). This is viewed by numerous researchers as a subfamily of the Nemonychidae, others see it as a separate family that are close to the recent Belidae .

Another argument for the old age of the Nemonychidae is their attachment to conifers as host plants. Since the bed covers are probably not much older than the Lower Cretaceous, the Nemonychidae family is probably older than them. It is assumed that it is a relic group that has survived from the root group of today's weevils. Their more successful relatives who migrated to angiosperms could have reformed tens of thousands of species while remaining almost unchanged.

Web links

Commons : Nemonychidae  - Collection of images, videos and audio files

Individual evidence

  1. ↑ a b c d Guillermo Kuschel & Richard AB Leschen (2010): Phylogeny and taxonomy of the Rhinorhynchinae (Coleoptera: Nemonychidae). Invertebrate Systematics 24: 573-615.
  2. ↑ AA Legalov (2009): Annotated Checklist of fossil and recent species of the family nemonychidae (Coleoptera) from the world fauna. Amurian zoological journal. 1 (3): 200-213.
  3. ↑ G. Kuschel & BM May (1997): A new genus and species of Nemonychidae (Coleoptera) associated with Araucaria angustifolia in Brazil. New Zealand Entomologist Vol. 20: 15-22.
  4. ↑ a b c G. Kuschel: The Nearctic Nemonychidae (Coleoptera: Curculionoidea). Entomologica Scandinavica 20 (2): 121-171.
  5. ↑ RT Thompson (1992): Observations on the morphology and classification of weevils (Coleoptera, Curculionoidea) with a key to major groups. Journal of Natural History, 26 (4): 835-891. doi : 10.1080 / 00222939200770511
  6. ↑ Brenda Μ. May (1993): Larvae of Curculionoidea (Insecta: Coleoptera): A systematic overview. In: Lincoln, NZ (editor): Fauna of New Zealand, No. 28. Manaaki Whenua Press.
  7. ↑ a b c d G. Kuschel (1983): Past and Present of the Relict Family Nemonychidae (Coleoptera, Curculionoidea). GeoJournal, Vol. 7, No. 6: 499-504.
  8. ↑ Christopher HC Lyal & MA Alonso-Zarazaga (2003): Case 3093. Nemonychidae Bedel, November 1882 (Insecta, Coleoptera): proposed precedence over Cimberididae Gozis, March 1882, and Cimberis Gozis, 1881: proposed conservation of usage. Bulletin of Zoological Nomenclature 60 (4): 275-280.
  9. ↑ AE Marvaldi, AS Sequeira, CW O'Brien, BD Farrell (2002): Molecular and morphological phylogenetics of weevils (Coleoptera: Curculionoidea): do niche shifts accompany diversification? Systematic Biology 51: 761-785.
  10. ↑ DD McKenna, AS Sequeira, AE Marvaldi, BD Farrell (2009): Temporal lags and overlap in the diversification of weevils and flowering plants. Proceedings of the National Academy of Sciences USA 106: 7083-7088. doi : 10.1073 / pnas.0810618106
  11. ↑ G. Kuschel (1995): A phylogenetic classification of Curculionoidea to families and subfamilies. Memoirs of the Entomological Society of Washington 14: 5-33.
  12. ↑ a b Vadim G. Gratshev & Vladimir V. Zherikhin (2003): The fossil record of weevils and related beetle families (Coleoptera, Curculionoidea). Acta zoologica cracoviensia, 46 (suppl.- Fossil Insects): 129-138.
  13. ^ Ming Liu, Dong Ren, Jingjing Tan (2006). New fossil weevils (Coleoptera, Curculionoidea, Nemonychidae) from the Jehol Biota of western Liaoning, China. Annales zoologici 56 (4): 605-612
  14. ↑ A.Riedel (2010): A new tribe, genus and species of nemonychidae from Baltic amber (Coleoptera: Curculionoidea: nemonychidae: Cimberidinae). Insect Systematics & Evolution 41, 29-38. doi : 10.1163 / 139956009X12550095535792
  15. ^ BD Farrell (1998): “Inordinate fondness” explained: why are there so many beetles? Science 281: 553-557.