Cybister

Cybister
Cybister fimbriolatus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Dytiscidae
Subfamily: Cybistrinae
Tribe: Cybistrini
Genus: Cybister
Curtis, 1827
Cybister lateralimarginalis Comparison of Cybister and Dytiscus larvae

Cybister ('kybistētēr' = diver, tumbler), is a genus of beetle in family Dytiscidae. They are found in much of the world, including all continents except Antarctica. As of 2021 there are 96 species and 9 additional subspecies among four subgenera in the genus.

Description by Muthiah R

Adult Cybister have broad hind legs with unequal tarsal claws (the inner claw being smaller and sometimes absent) and a fringe on the outer margin of the tarsus. They range in length from 13 mm (C. parvus from Brazil) to 43 mm (C. bimaculatus from the Afrotropics). Adult males of the North American species have several ridges on the coxae of the hind legs, forming a stridulatory device.

Larvae have a frontal tooth on the head and lack cerci. North American species can grow up to 80 mm long.

Ecology

Cybister live in lentic (still fresh water) habitats that have vegetation.

Like other diving beetles, Cybister are predatory. Larvae of C. japonicus prey on insects (mainly Odonata nymphs and the backswimmer Notonecta triguttata) in their first two instars, while third-instar larvae prey on vertebrates (tadpoles and fish). Larvae of C. rugosus feed on both invertebrates and vertebrates in all instars.

Importance

Cybister chinensis (sometimes misidentified as C. japonicus) is used in a game in Korea. The water beetle game (mul bang gae nori) is played in an oval, water-filled tank with vertical flanges along its inner edge and prizes on the tank rim. The game is played by dropping a C. chinensis through a funnel into the center of the tank, after which it swims towards the edge of the tank and stops in one of the slots formed by the metal flanges. If a prize is above this slot, the player wins it.

The swimming behaviour of C. lateralimarginalis has inspired (biomimetics) the design of a legged underwater robot.

List of species

Subgenus Cybister Curtis, 1827

Subgenus Megadytoides Brinck, 1945

Subgenus Melanectes Brinck, 1945

Subgenus Neocybister K.B. Miller, Bergsten & Whiting, 2007

Subgenus unknown

Fossil species

These seven extinct species are known only from fossils:

References

  1. ^ Miller, K.B.; J. Bergsten (2016). Diving Beetles of the World: Systematics and Biology of the Dytiscidae. pp. 131–132. ISBN 978-1-4214-2054-7.
  2. ^ Roberts, C H (1905). "The Distinctive Characters of the Eastern Species of the Genera Dytiscus and Cybister". Journal of the New York Entomological Society. 13: 103–107.
  3. ^ Nilsson, Anders N.; Hájek, Jiří (2021). "A World Catalogue of the Family Dytiscidae or the Diving Beetles (Coleoptera, Adephaga)" (PDF) (1.I.2021 ed.).
  4. ^ a b "Genus Cybister". bugguide.net. Retrieved 2023-03-02.
  5. ^ a b Arce-Pérez, Roberto; Novelo-Gutiérrez, Rodolfo; Fery, Hans (2021-11-04). "Cybister (s. str.) poblanus sp. n. from Mexico and notes on other species of Cybistrinae (Coleoptera: Dytiscidae)". Zootaxa. 5061 (2): 323–339. doi:10.11646/zootaxa.5061.2.5. ISSN 1175-5334.
  6. ^ Liao, Wenfei (2018-08-19). "Cybister, an Immigrant in Finland". Wenfei's Blog. Retrieved 2023-03-02.
  7. ^ Ohba, Shin-Ya (2009-06-01). "Ontogenetic Dietary Shift in the Larvae of Cybister japonicus (Coleoptera: Dytiscidae) in Japanese Rice Fields". Environmental Entomology. 38 (3): 856–860. doi:10.1603/022.038.0339. ISSN 0046-225X.
  8. ^ Yamasaki, Shun; Watanabe, Kohei; Ohba, Shin‐ya (2022). "Larval feeding habits of the large‐bodied diving beetle Cybister rugosus (Coleoptera: Dytiscidae) under laboratory conditions". Entomological Science. 25 (2). doi:10.1111/ens.12510. ISSN 1343-8786.
  9. ^ Pemberton, R. W. (1990). "The Korean water beetle game". Pan-Pacific Entomologist. 66 (2): 172–174.
  10. ^ Kim, Heejoong; Lee, Jihong (2017). "Design, swimming motion planning and implementation of a legged underwater robot (CALEB10: D.BeeBot) by biomimetic approach". Ocean Engineering. 130: 310–327. doi:10.1016/j.oceaneng.2016.11.006.

External links

Taxon identifiers
Cybister