Ptiliidae

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Ptiliidae
Temporal range: Barremian–Recent
Ptenidium pusillum (Gyllenhal, 1808) (3232041856).jpg
Ptenidium pusillum
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Infraorder: Staphyliniformia
Superfamily: Staphylinoidea
Family: Ptiliidae
Erichson, 1845 [1]
Subfamilies
Synonyms
  • Trichopterygidae Erichson, 1845

Ptiliidae is a family of very tiny beetles (including the smallest of all beetles) with a cosmopolitan distribution. They are colloquially called featherwing beetles, because the hindwings are narrow and feathery. [2]

Contents

There are approximately 600 described species in 80 genera, [2] but large numbers of specimens in collections await description and the true number of species is likely to be much higher than this. [3]

The family is divided into 3 subfamilies: [2]

Description

Ptiliidae figures 1-9 note the feathered wings Reitter-1908 table65.jpg
Ptiliidae figures 1-9 note the feathered wings

This family contains the smallest of all beetles, [3] with a length when fully grown of 0.3–4.0 millimetres (0.01–0.16 in). [2] The weight is approximately 0.4 milligrams. [4] Ptillid wings are feathery due to the much higher effective viscosity of air at small body sizes, which makes normal insect wings much less efficient. Unlike other small insects with feathery wings, such as parasitic wasps like fairyflies, ptillids do not fly using a clap and fling motion, but instead fly using a figure of eight pattern where the wings clap at the apex of the upward and downward strokes. They are capable of flying at speeds comparable to their larger relatives. [5]

The small size has forced many species to sacrifice some of their anatomy, like the heart, crop, and gizzard. While the exoskeleton and respiration system of the insects seems to be the major limiting factors regarding how large they can get, the limit for how small they can become appears to be related to the space required for their nervous and reproductive systems. [6]

Many species (e.g. in Ptinella , Pteryx , and Ptinellodes ) are polymorphic, with two morphs so distinct that they appear to be different species or genera. There is a normal morph with well-developed eyes, wings and pigmentation, and also a vestigial morph in which these features are reduced or lacking. The vestigial morph is more common, making up 90% or more of individuals.

Life cycle and reproduction

Ptiliidae have a short life cycle, with an egg-adult time of 32-45 days observed for three British species of Ptinella . They can reproduce continuously under favourable conditions, with larvae often co-occuring with both teneral and fully hardened adults at different times of the year. The eggs are very large in comparison to the adult female (nearly half her body length) so only one egg at a time can be developed and laid. Thelytokous parthenogenesis is exhibited by several species, these only being known from females. [3]

Ecology

Adults and larvae are microphagous, feeding on the spores and hyphae of fungi, as well as other organic detritus. They are found in a wide variety of habitats, including rotting and fungus infested wood, tree holes, under kelp along shorelines and within or near ant and termite nests. [7]

Evolution

Fossil ptiliids have been recorded from the Oligocene, roughly 30 million years ago [2] from the Eocene, 46.2–43.5 million years ago, and from the Cretaceous Lebanese and Burmese amber, dated to 125 and 99 million years ago, respectively. [8]

Related Research Articles

<span class="mw-page-title-main">Beetle</span> Order of insects

Beetles are insects that form the order Coleoptera, in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 described species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal species; new species are discovered frequently, with estimates suggesting that there are between 0.9 and 2.1 million total species. Found in almost every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles often feed on plants and fungi, break down animal and plant debris, and eat other invertebrates. Some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae eat aphids, scale insects, thrips, and other plant-sucking insects that damage crops.

<span class="mw-page-title-main">Silphidae</span> Family of beetles

Silphidae is a family of beetles that are known commonly as large carrion beetles, carrion beetles or burying beetles. There are two subfamilies: Silphinae and Nicrophorinae. Nicrophorines are sometimes known as sexton beetles. The number of species is relatively small at around two hundred. They are more diverse in the temperate region although a few tropical endemics are known. Both subfamilies feed on decaying organic matter such as dead animals. The subfamilies differ in which uses parental care and which types of carcasses they prefer. Silphidae are considered to be of importance to forensic entomologists because when they are found on a decaying body they are used to help estimate a post-mortem interval.

<span class="mw-page-title-main">Thrips</span> Order of insects

Thrips are minute, slender insects with fringed wings and unique asymmetrical mouthparts. Entomologists have described approximately 6,000 species. They fly only weakly and their feathery wings are unsuitable for conventional flight; instead, thrips exploit an unusual mechanism, clap and fling, to create lift using an unsteady circulation pattern with transient vortices near the wings.

<span class="mw-page-title-main">Telephone-pole beetle</span> Species of beetle

The telephone-pole beetle is a beetle native to the eastern United States, and the only living representative of the otherwise extinct family Micromalthidae. They have an unusual lifecycle involving asexually reproducing (parthenogenetic) female larvae, as well as non-functional "ghost adults".

<span class="mw-page-title-main">Sawfly</span> Suborder of insects

Sawflies are the insects of the suborder Symphyta within the order Hymenoptera, alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor, which the females use to cut into the plants where they lay their eggs. The name is associated especially with the Tenthredinoidea, by far the largest superfamily in the suborder, with about 7,000 known species; in the entire suborder, there are 8,000 described species in more than 800 genera. Symphyta is paraphyletic, consisting of several basal groups within the order Hymenoptera, each one rooted inside the previous group, ending with the Apocrita which are not sawflies.

<span class="mw-page-title-main">Histeridae</span> Family of beetles

Histeridae is a family of beetles commonly known as clown beetles or hister beetles. This very diverse group of beetles contains 3,900 species found worldwide. They can be easily identified by their shortened elytra that leaves two of the seven tergites exposed, and their geniculate (elbowed) antennae with clubbed ends. These predatory feeders are most active at night and will fake death if they feel threatened. This family of beetles will occupy almost any kind of niche throughout the world. Hister beetles have proved useful during forensic investigations to help in time of death estimation. Also, certain species are used in the control of livestock pests that infest dung and to control houseflies. Because they are predacious and will even eat other hister beetles, they must be isolated when collected.

<span class="mw-page-title-main">Staphyliniformia</span> Infraorder of beetles

Staphyliniformia is a large infraorder of beetles. It contains over 70,000 described species from all regions of the world. Most species occur in moist habitats - various kinds of rotting plant debris, fungi, dung, carrion, many live in fresh water.

<span class="mw-page-title-main">Dynastinae</span> Subfamily of beetles

Dynastinae or rhinoceros beetles are a subfamily of the scarab beetle family (Scarabaeidae). Other common names – some for particular groups of rhinoceros beetles – include Hercules beetles, unicorn beetles or horn beetles. Over 1500 species and 225 genera of rhinoceros beetles are known.

<span class="mw-page-title-main">Staphylinoidea</span> Superfamily of beetles

Staphylinoidea is a superfamily of beetles. It is a very large and diverse group with worldwide distribution.

<span class="mw-page-title-main">Cleridae</span> Checkered beetles

Cleridae are a family of beetles of the superfamily Cleroidea. They are commonly known as checkered beetles. The family Cleridae has a worldwide distribution, and a variety of habitats and feeding preferences.

<span class="mw-page-title-main">Chrysomelinae</span> Subfamily of beetles

The Chrysomelinae are a subfamily of leaf beetles (Chrysomelidae), commonly known as broad-bodied leaf beetles or broad-shouldered leaf beetles. It includes some 3,000 species around the world.

<i>Pteryx</i> Genus of beetles

Pteryx is a genus of beetles that is typically found in northern bogs in the Northern Hemisphere. They belong to the family Ptiliidae which is referred to as feather-winged beetles as the hindwings are narrow and feather-like. Like most of the rest of the family, Pteryx are very small and live in rotting vegetative matter. They prefer rotting wood and are generally found under the bark of rotting logs or stumps.

<span class="mw-page-title-main">Brachypsectridae</span> Family of beetles

The Brachypsectridae are a family of beetles commonly known as the Texas beetles. There are only two extant genera, Brachypsectra and Asiopsectra. Brachypsectra has a cosmopolitan distribution, mostly in arid regions, while Asiopsectra is found in Central Asia and the Middle East.

<i>Scydosella</i> Genus of beetles

Scydosella is a genus of beetles that consists of only one species Scydosella musawasensis. The species is regarded as the smallest free-living insect, as well as the smallest beetle. They are among featherwing beetle, named because of their feather-like spiny wings. It was first discovered in Nicaragua, and described in 1999 by Wesley Eugene Hall of the University of Nebraska State Museum. The initial discovery consisted of very few specimens, and exact measurements were not conclusive. Because of their tiny size, they were difficult to observe under microscope after preservation. The generally accepted size was 0.300 mm in length. On 8 February 2015, Alexey Polilov of the Lomonosov Moscow State University collected 85 specimens in Chicaque National Park, Colombia. They were discovered on a layer of fungus on which they feed. From these specimens exact measurements could be made, and was found that the smallest individual is only 0.325 mm long. The largest individual is 0.352 mm long, and the average length of all the specimens is 0.338 mm. The body is elongated and oval in shape, yellowish-brown in colour, and its antennae are split into 10 segments.

Discheramocephalus brucei is a species of feather-winged beetle, the smallest beetles on earth, first found in Cameroon.

Discheramocephalus elisabethae is a species of feather-winged beetle, the smallest beetles on earth, first found in Cameroon.

Discheramocephalus stewarti is a species of feather-winged beetle, the smallest beetles on earth, first found in Bolivia.

Discheramocephalus jarmilae is a species of feather-winged beetle, the smallest beetles on earth, first found in Bolivia.

Discheramocephalus minutissimus is a species of feather-winged beetle, the smallest beetles on earth, first found in Indonesia. This species' adults have a body length of approximately 400 to 426µm. According to Grebennikov, the main factor limiting miniaturisation of female insects is an egg size significant enough in size to produce viable larvae. This size threshold is sometimes overcome, reaching limits of 180 and 130 µm in females and males, respectively, according to the author. Brain size is possibly the second most important factor limiting miniaturisation in this class.

Discheramocephalus is a genus of feather-winged beetles, the smallest beetles on earth, first found in Cameroon. It was originally described in 2007 as a monotypic genus. Six additional species were added in 2008, and two were added in 2013.

References

  1. Bouchard, Patrice; Bousquet, Yves; Davies, Anthony E.; Alonso-Zarazaga, Miguel A.; Lawrence, John F.; Lyal, Chris H. C.; Newton, Alfred F.; Reid, Chris A. M.; Schmitt, Michael; Ślipiński, S. Adam; Smith, Andrew B. T. (2011). "Family-group names in Coleoptera (Insecta)". ZooKeys (88): 1–972. doi: 10.3897/zookeys.88.807 . PMC   3088472 . PMID   21594053.
  2. 1 2 3 4 5 Christopher G. Mayka & Mikael Sörensson (2010). "Featherwing beetles (Coleoptera: Ptiliidae)". In Donald F. McAlpine & Ian M. Smith (ed.). Assessment of Species Diversity in the Atlantic Maritime Ecozone. NRC Research Press. pp. 433–438. ISBN   9780660198354.
  3. 1 2 3 Henry S. Dybas (2000). "Featherwing beetles". DPI Entomology Circular. University of Florida. 218. EENY-177. Retrieved October 22, 2013.
  4. "Insects: Beetle". San Diego Zoo. 2008. Retrieved July 20, 2008.
  5. Farisenkov, Sergey E.; Kolomenskiy, Dmitry; Petrov, Pyotr N.; Engels, Thomas; Lapina, Nadezhda A.; Lehmann, Fritz-Olaf; Onishi, Ryo; Liu, Hao; Polilov, Alexey A. (2022-02-03). "Novel flight style and light wings boost flight performance of tiny beetles". Nature. 602 (7895): 96–100. doi:10.1038/s41586-021-04303-7. ISSN   0028-0836. PMC   8810381 . PMID   35046578.
  6. World’s Smallest Insect Pays a Hefty Price for its Size
  7. Eugene Hall, W.. "Ptiliidae Erichson, 1845: Coleoptera, Beetles". Handbook of Zoology Online, edited by Andreas Schmidt-Rhaesa. Berlin, Boston: De Gruyter, 2016. Accessed 2022-10-02.
  8. Floyd W. Shockley; Dale Greenwalt (2013). "Ptenidium kishenehnicum (Coleoptera: Ptiliidae), a New Fossil Described from the Kishenehn Oil Shales, with a Checklist of Previously Known Fossil Ptiliids". Proceedings of the Entomological Society of Washington. 115 (2): 173–181. doi:10.4289/0013-8797.115.2.173. S2CID   28658836.