Rain beetle

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Rain beetles
Temporal range: Late Cretaceous–recent
Pleocoma.jpg
Pleocoma
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Infraorder: Scarabaeiformia
Superfamily: Scarabaeoidea
Family: Pleocomidae
LeConte, 1861
Genera

The rain beetles are a group of beetles whose extant species are found only in the far west of North America. [1] They spend most of their lives underground, emerging in response to rain or snow, thus the common name. Formerly classified in the Scarabaeidae (and later the Geotrupidae), they are currently assigned to their own family Pleocomidae, considered the sister group to all the remaining families of Scarabaeoidea. The family contains a single extant genus, Pleocoma , and two extinct genera, Cretocoma, described in 2002 from Late Cretaceous deposits in Mongolia, [2] and Proteroscarabeus of Late Cretaceous China. [3]

Contents

Biology

Adult rain beetles lack functioning mouthparts and are unable to feed. Instead, they rely on fat storage from when they were larvae. Larvae feed on the roots of shrubs and trees, as well as fungi and other organic matter. [4] Larvae feeding on orchard trees can result in patches or winding bands on tree roots, and ultimately causes reduced foliage and fruit yield for trees. [5]

Rain beetles spend most of their lives as larvae underground, burrowing up to twelve feet below the surface. Larvae can live between 7 and 14 years before they pupate into adulthood. They need at least seven instars, or developmental stages between molts, before they can pupate, but some may take more. [6]

Male rain beetles exhibit most mating behavior during winter nights. As the females are flightless, the males spend a large portion of time walking on snow in search of them. This also limits the known modern distribution of the beetles. [7] The male's ability to maintain a high internal temperature, up to 95 degrees, is critical to their mating and survival prospects, as their thoracic pile is ineffective insulation. [8]

The lifespan of adult rain beetles is also dependent on their sex. The males live only a few days, expending most of their energy in search of mates, while the females can survive a few months in their burrow. [7]

Distribution

Most rain beetle populations are in mountainous California. They have not been found in the desert but also live in parts of the Sacramento Valley and coastal plain of the San Diego Valley. Extant members of Pleocoma are known from extreme southern Washington, throughout the mountains of Oregon and California, and into the extreme north of Baja California. [1]

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 Holometabola. 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. Some others also have unusual characteristics, such as fireflies, which use a light-emitting organ for mating and communication purposes.

<span class="mw-page-title-main">Stag beetle</span> Family of insects

Stag beetles are a family of about 1,200 species of beetles in the family Lucanidae, currently classified in four subfamilies. Some species grow to over 12 centimetres, but most to about 5 cm (2 in).

<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 known living representative of the otherwise extinct family Micromalthidae. Larvae of the beetle live in decaying wood and can be pests to wooden structures, lending them their common name, the 'telephone-pole beetle.'

<i>Glaresis</i> Genus of beetles

Glaresis is a genus of beetles, sometimes called "Enigmatic scarab beetles", in its own family, the Glaresidae. It is closely related to, and was formerly included in, the family Scarabaeidae. Although its members occur in arid and sandy areas worldwide, only the nocturnal adults have ever been collected, and both the larvae and biology of Glaresis are as yet unknown. Due to their narrow habitat associations, a great number of these species occur in extremely limited geographic areas, and are accordingly imperiled by habitat destruction.

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

Trogidae, sometimes called hide beetles, is a family of beetles with a distinctive warty or bumpy appearance. Found worldwide, the family includes about 300 species contained in four or five genera.

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

Scarabaeoidea is a superfamily of beetles, the only subgroup of the infraorder Scarabaeiformia. Around 35,000 species are placed in this superfamily and some 200 new species are described each year. Its constituent families are also undergoing revision presently, and the family list below is only preliminary. This superfamily includes some of the largest beetles extant today, including rhinoceros beetles, (Dynastinae), the Hercules beetle and Goliath beetles.

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

The Hercules beetle is a species of rhinoceros beetle native to the rainforests of southern Mexico, Central America, South America, and the Lesser Antilles. It is the longest extant species of beetle in the world, and is also one of the largest flying insects in the world.

<i>Dynastes tityus</i> Species of beetle

Dynastes tityus, the eastern Hercules beetle, is a species of rhinoceros beetle native to the Eastern United States. The adult's elytra are green, gray or tan, with black markings, and the whole animal, including the male's horns, may reach 60 mm (2.4 in) in length. The larvae feed on decaying wood from various trees.

<i>Pleocoma</i> Genus of beetles

Pleocoma is the only extant genus of rain beetles and is endemic to the Pacific states of North America. Fossil remains of Pleocoma have been found in the Yixian Formation in China, suggesting beetles in this genus have existed in something like their present form since at least the Cretaceous period. There are 27 described species in Pleocoma.

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

Ripiphoridae is a cosmopolitan family of some 450 described species of beetles sometimes called "wedge-shaped beetles". Ripiphoridae are unusual among beetle families in that many species are hypermetamorphic parasitoids, an attribute that they share with the Meloidae. Members of the family differ in their choice of hosts, but most attack various species of bees or wasps, while some others attack cockroaches or beetles. Many species of Ripiphoridae have abbreviated elytra, and flabellate or pectinate antennae.

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

Glaphyridae is a family of beetles, commonly known as bumble bee scarab beetles. There are eight extant genera with about 80 species distributed worldwide and two extinct genera described from the Aptian aged Yixian Formation of China. There are cases of flower-beetle interactions, in the southeast Mediterranean region between red bowl-shaped flowers and Glaphyridae beetles.

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

Helotidae is a family of beetles, in the suborder Polyphaga. The family includes about five extant genera, Helota MacLeay, Neohelota Ohta, Afrohelotina Kirejtshuk, Metahelotella Kirejtshuk, and Strophohelota Kirejtshuk. Helotidae are found mainly in the Old World tropics and are absent from Australia and Madagascar. The antennae are clubbed on the final three segments and is retractable within grooves under the head. The wings have reduced venation with just 4 anal veins. Helotids are known to be associated with sap, fruit and flowers, and the larvae of some species are known to bore into wood in order to pupate.

<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.

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

Rutelinae or shining leaf chafers is a subfamily of the scarab beetles. It is a very diverse group; distributed over most of the world, it contains some 200 genera with over 4,000 described species in 7 tribes. Several taxa have yet to be described. A few recent classifications include the tribe Hopliini, but this is not generally accepted.

Pleocoma shastensis is a species of rain beetle in the family Pleocomidae. It is found in North America.

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

Eulichadidae is a family of beetles belonging to Elateriformia. There are two extant genera, Eulichas with several dozen species native to the Indomalayan realm of Asia, and Stenocolus, with a single species native to Western North America. The larvae are aquatic, with the larvae of Eulichas being found in sandy sediments of clean forest streams, while the larvae of Stenocolus are found under rocks and in leaf packs in low elevation streams and rivers. They are herbivious/saprophagous with larval specimens of Eulichas having been found with wood particles in their stomachs, while the larvae of Stenocolus are known to feed on decaying roots and detritus. The adults are terrestrial, with specimens of Eulichas typically found using light, while specimens of Stenocolus are typically found in riparian vegetation, and are not attracted to light. Potential extinct genera have been described from Mesozoic rocks, but the placement of several of these taxa in the family is disputed.

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

Throscidae is a family of elateroid beetles found worldwide with around 150 species in 5 extant genera. The larvae are soil-dwelling, siphoning fluid from mycorrhizae attached to trees. The adults are short-lived, with the adult males being noted for a complex mating dance. Like some other elateroids, they are capable of clicking.

Pleocoma rickseckeri is a species of rain beetle in the family Pleocomidae. It is found in North America. It was named in honor of Lucius Edgar Ricksecker.

Pleocoma hirticollis is a species of rain beetle in the family Pleocomidae. It is found in North America.

Pleocoma rubiginosa is a species of rain beetle in the family Pleocomidae. It is found in North America.

References

  1. 1 2 Hovore, Frank T. "Generic Guide to New World Scarab Beetles". unsm-ento.unl.edu. University of Nebraska State Museum - Division of Entomology. Retrieved 14 December 2020.
  2. Frank-Thorsten Krell. "Catalogue of fossil Scarabaeoidea (Coleoptera: Polyphaga) of the Mesozoic and Tertiary" (PDF). Natural History Museum. Archived from the original (PDF) on July 20, 2011. Retrieved March 7, 2011.
  3. Krell, Frank-Thorsten. "The fossil record of Mesozoic and Tertiary Scarabaeoidea (Coleoptera: Polyphaga)." Invertebrate Systematics 14.6 (2000): 871-905.
  4. "Rain Beetles Are Curious Critters". ANR Blogs. Retrieved 2024-10-31.
  5. "Rain Beetles | WSU Tree Fruit | Washington State University" . Retrieved 2024-03-16.
  6. Parent, Emily. "Hike with a scientist: Seeking the secrets of Oregon's mysterious rain beetles in Corvallis". Statesman Journal. Retrieved 2024-10-31.
  7. 1 2 Evans, Arthur V.; Hogue, James N., eds. (2005-12-31). Introduction to California Beetles. University of California Press. doi:10.1525/9780520937567. ISBN   978-0-520-93756-7.
  8. Morgan, Kenneth R. (1987-03-01). "Temperature Regulation, Energy Metabolism and Mate-Searching in Rain Beetles (Pleocoma Spp.), Winter-Active, Endothermic Scarabs (Coleoptera)". Journal of Experimental Biology. 128 (1): 107–122. doi:10.1242/jeb.128.1.107. ISSN   0022-0949.