Tytthus

Tytthus
Tytthus parviceps
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hemiptera
Suborder:	Heteroptera
Family:	Miridae
Subfamily:	Phylinae
Tribe:	Semiini
Genus:	Tytthus Fieber, 1864 [1]
Type species
Tytthus pubescens (Knight, 1931)
Species
See text
Synonyms [2] [3] [4]
BreddiniessaKirkaldy, 1903 CyllocepsUhler, 1893 IsoprobaOsborn and Drake, 1915 PeriscopusBreddin, 1896

Tytthus is a genus of insects in family Miridae, the plant bugs. ^[4] They are carnivorous, feeding upon the eggs of various planthoppers in the family Delphacidae, and thus are important in the biological control of pests. The genus is distributed throughout the Holarctic of the Northern Hemisphere, but species are also found in the tropics, in China, South America, Australia, and the Indo-Pacific. ^[4]

Type species

In 1860 Gustav Flor described a bug he found in Estonia and named it Capsus geminus. ^[5] When Fieber established the genus Tytthus in 1864, he named two species to the genus, Zetterstedt's Capus pygmaeus and Flor's Capus geminus. Capus geminus thus became Tytthus geminus, by which name it was known as for well over a hundred years. ^[6] In 1906 Kirkaldy named then Tytthus geminus as the type species for the genus. ^[7] But, as Henry and Wheeler discovered in 1988, the name Capsus geminus was not available in 1860, because Thomas Say had already used it 1832 for another species entirely. ^[8] So, after researching the various previous nomenclaturial acts regarding the bug, they discovered that the next available name was one used by Harry H. Knight in 1931 to describe the same bug as if it were a new species, ^[9] but placing it in the genus Cyrtorhinus Fieber, 1858 as Reuter had made Tytthus a junior synonym of Cyrtorhinus. ^{[10] [11]} Knight's name, Cyrtorhinus pubescens was the oldest junior synonym. ^[11] In 1992, Wheeler and Henry published a treatise reviewing the Miridae family occurring in the Holarctic, and formally corrected the nomenclaturial error in accordance with the International Code of Zoological Nomenclature, ^[11] with the result that the type species was henceforth called Tytthus pubescens (Knight, 1931). ^{[4] [12]}

Tribe

In 1955 Carvalho and Southwood (1955) rescued Tytthus from synonymity with the look-alike genus Cyrtorhinus Fieber, 1858, and showed that Tytthus belonged in the subfamily Phylinae based upon analysis of the pretarsal structures and the male genitalia. ^[2] And as a result it was placed in the catch-all (nominal) tribe Phylini when Carvalho created it in 1958. ^[3] Similarities in a number of structures including the U-shaped endosoma (internal holding pouch for the tip of the aedeagus), the fine setae (bristles) of the parempodia, and the relative small size of the male genitalia, led Schuh in 1974 to place Tytthus in the Leucophoropterini along with the genus Karoocapsus. ^[13]

In 1999, however, Kerzhner and Josifov conservatively placed the Leucophoropterini as a synonym under the Phylini, ^[14] following Linnavuouri, whose analysis in 1993 led him to believe that it was unnecessary to split the Phylini tribe based on the available evidence. ^[15] Evidence was soon forthcoming from Menard and Schuh in 2011, where molecular and morphological evidence provided strong support for the monophyly of Leucophoropterini, so long as Tytthus, Karoocapsus and five other genera were grouped outside the tribe. ^[16] In 2013 the Semiini tribe was resurrected and redefined by Menard, Schuh and Woolley, ^[17] and Tytthus was placed with the Semiini. ^[18]

Species

• Tytthus alboornatus (Knight, 1931)
• Tytthus amazonicus Carvalho, 1983
• Tytthus balli (Knight, 1931)
• Tytthus chinensis (Stål 1860)
• Tytthus columbiensis Carvalho, 1984
• Tytthus entrerianus Carvalho and Carpintero, 1986
• Tytthus femoralis Henry, 2012
• Tytthus fuscicornis Henry, 2012
• Tytthus insperatus (Knight, 1925)
• Tytthus juturnaiba Carvalho and Wallerstein, 1978
• Tytthus mexicanus Henry, 2012
• Tytthus montanus Carvalho and Southwood, 1955
• Tytthus mundulus (Breddin, 1896)
• Tytthus neotropicalis (Carvalho, 1954)
• Tytthus pallidus Henry, 2012
• Tytthus panamensis Carvalho and Southwood, 1955
• Tytthus parviceps (Reuter, 1890)
• Tytthus picea (Osborn and Drake, 1915) ^[4]
• Tytthus pubescens (Knight, 1931) ^[19]
• Tytthus pygmaeus (Zetterstedt, 1840)
• Tytthus uniformis Henry, 2012
• Tytthus vagus (Knight, 1923)
• Tytthus wheeleri Henry, 2012
• Tytthus zwaluwenburgi (Usinger, 1944)

No longer valid

• Tytthus annulicollis(Poppius, 1915) junior synonym Tytthus chinensis (Stål 1860)
• Tytthus elongatus(Poppius, 1915) junior synonym Tytthus chinensis (Stål 1860)
• Tytthus flaveolusReuter, 1871 now Fieberocapsus flaveolus (Reuter, 1871)
• Tytthus flavescensStichel, 1956 junior synonym Tytthus pygmaeus (Zetterstedt, 1840)
• Tytthus flavomarginatusStichel, 1956 junior synonym Tytthus pygmaeus (Zetterstedt, 1840)
• Tytthus floriStichel, 1956 junior synonym Tytthus pubescens (Knight, 1931)
• Tytthus geminus(Flor, 1860) now Tytthus pubescens (Knight, 1931)
• Tytthus hondurensisCarvalho junior synonym Tytthus picea (Osborn and Drake, 1915)
• Tytthus insignisDouglas and Scott, 1866 junior synonym Tytthus pygmaeus (Zetterstedt, 1840)
• Tytthus intermediusStichel, 1956 junior synonym Tytthus parviceps (Reuter, 1890)
• Tytthus koreanusJosifov and Kerzhner, 1972 junior synonym Tytthus chinensis (Stål 1860)
• Tytthus pallidiorStichel, 1956 junior synonym Tytthus pubescens (Knight, 1931)
• Tytthus pellicia(Uhler, 1893) junior synonym Tytthus parviceps (Reuter, 1890)
• Tytthus pellucens(Boheman, 1852) junior synonym Tytthus pygmaeus (Zetterstedt, 1840)
• Tytthus riveti(Cheesman, 1927) junior synonym Tytthus chinensis (Stål 1860)
• Tytthus thoracicus(Horvath, 1909) junior synonym Tytthus parviceps (Reuter, 1890)

Description

Adults range from the males of Tytthus wheeleri, which are just over a millimeter long, to T. mundulus, which is about 3.60 mm in length. ^[4] Adults have shiny, broad, globose heads. The eyes have a yellow dot on the inside edge. ^[4] In general, they have dark brown to black heads, a pronotum and scutellum, a pale translucent hemelytra, slender legs, and slender antennae. ^[4] Tytthus resembles the genus Cyrtorhinus , ^[4] and was previously considered to be a junior synonym. ^[10]

Ecology

The members of Tytthus feed on the eggs of Delphacidae and a few on the eggs of other planthoppers. ^[4] One of the early success stories of biological pest control was Frederick Muir's importation of Tytthus mundulus from Queensland, Australia to Hawaii to eat the eggs of Perkinsiella saccharicida that fed on the sugar cane crops. ^[20]

References

1. Fieber, Franz Xaver (1864). "Neuere Entdeckungen in europäischen Hemipteren (" (PDF). Wiener Entomologische Monatschrift. 8 (3): 65–86, pages 82 to 84. Archived (PDF) from the original on 26 January 2014.
2. Carvalho, José Cândido de Melo; Southwood, T. R. E. (1955). "Revisao do complexo Cyrtorhinus Fieber-Mecomma Fieber (Hemiptera, Heteroptera, Miridae)". Boletim do Museu Paraense Emilio Goeldi, Zoologia. 11: 7–72.
3. Carvalho, José Cândido de Melo (1958). Catálogo dos mirídeos do mundo, 1758-1956. Parte II. Subfamilia Phylinae. (Arquivos do Museu Nacional, volume 45). Rio de Janeiro: Oficinas Gráficas do IBGE. p. 66.
4. Henry, T. J. (2012). "Revision of the plant bug genus Tytthus (Hemiptera, Heteroptera, Miridae, Phylinae)". ZooKeys (220): 1–114. doi: 10.3897/zookeys.220.2178 . PMC   3459032 . PMID   23077429.
5. Flor, Gustav (1860). Die Rhynchoten Livlands in systematischer Folge Beschrieben, Erster Theil: Rhynchota frontirostria Zett. (Hemiptera heteroptera Aut.). Dorpat: C. Schulz. p.  464.
6. Kelton, Leonard A. (1980). The insects and arachnids of Canada. Part 8, The plant bugs of the Prairie Provinces of Canada, Heteroptera: Miridae. (Agriculture Canada Research Branch Publication 1703). Ottawa: Canadian Government Publishing Centre. p. 303. ISBN   978-0-660-10613-7.
7. Kirkaldy, George W. (1906). "List of the genera of pagiopodous Hemiptera-Heteroptera, with their type species, from 1758 to 1904 (and also of the aquatic and semi-aquatic Trochalopoda)". Transactions of the American Entomological Society. 32: 117–156b, page 128.
8. Henry, Thomas J. & Wheeler, Alfred George Jr. (1988). "Family Miridae Hahn, 1833 (= Capsidae Burmeister, 1835). The plant bugs". In Henry, Thomas J. & Froeschner, Richard C. (eds.). Catalog of the Heteroptera, or True Bugs, of Canada and the Continental United States. Leiden, Netherlands: E. J. Brill. pp. 251–507, pages 457 &amp, 458. ISBN   978-0-916846-44-2.
9. Knight, Harry H. (1931). "Three new species of Cyrtorhinus from North America (Hemiptera, Miridae)" (PDF). Bulletin of the Brooklyn Entomological Society. 26: 171–173. Archived (PDF) from the original on 26 January 2014.
10. Reuter, Odo M. (1875). "Genera Cimicidarum Europae disposuit" (PDF). Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar. 3 (1): 1–66, page 31. doi:10.5962/bhl.part.4014. Archived (PDF) from the original on 26 March 2007.
11. Wheeler, Alfred George & Henry, Thomas J. (1992). A synthesis of the Holarctic Miridae (Heteroptera) : distribution, biology, and origin, with emphasis on North America. Lanham, Maryland: Entomological Society of America. pp. 140–141. ISBN   978-0-938522-39-3.
12. Ryan, Rob (2012). "An addendum to Southwood & Leston's Land and Water Bugs of the British Isles" (PDF). British Journal of Entomology and Natural History . 25 (4): 205–216. Archived (PDF) from the original on 26 January 2014.
13. Schuh, Randall Tobias (1974). "Orthotylinae and Phylinae (Hemiptera: miridae) of South Africa with a phylogenetic analysis of the ant-mimetic tribes of the two subfamilies for the world". Entomologica Americana. 47: 1–332.
14. Kerzhner I. M.; Josifov M. (1999). "Miridae". In Aukema, Berend; Rieger, Christian (eds.). Catalogue of the Heteroptera of the Palaearctic Region. Vol. 3, Cimicomorpha II. Amsterdam: Netherlands Entomological Society. pp. 1–577, page 300. ISBN   978-90-71912-19-1.
15. Linnavuori, R. E. (1993). "The Phylinae (Hemiptera: Miridae) of West, Central and north east Africa". Garcia de Orta, Série Zoologia. 18. Lisboa: 115–296.
16. Menard, Katrina L. & Schuh, Randall T. (2011). "Revision of Leucophoropterini: Diagnoses, key to genera, description of the Australian fauna, and descriptions of new Indo-Pacific genera and species (Insect: Hemiptera: Miridae)" (PDF). Bulletin of the American Museum of Natural History. 361: 1–159. doi:10.1206/361.1. hdl:2246/6142. S2CID   83502375.
17. Menard, Katrina L.; Schuh, Randall T. & Woolley, James B. (August 2014) [2013]. "Total-evidence phylogenetic analysis and reclassification of the Phylinae (Insecta: Heteroptera: Miridae), with the recognition of new tribes and subtribes and a redefinition of Phylini". Cladistics. 30 (4): 391–427. doi: 10.1111/cla.12052 . S2CID   84814137.
18. Schuh, Randall T. & Menard, Katrina L. (2013). "A revised classification of the Phylinae (Insecta, Heteroptera, Miridae): Arguments for the placement of genera" (PDF). American Museum Novitates (3785). New York: American Museum of Natural History: 37, 43. doi:10.1206/3785.2. hdl:2246/6451. OCLC   861298407. S2CID   85911892.
19. "Tytthus pubescens". Species-ID.
20. Usinger, R. L. (1939). "Distribution and host relationships of Cyrtorhinus (Hemiptera, Miridae)" (PDF). Proceedings of the Hawaiian Entomological Society. 10 (2): 271–273. Archived (PDF) from the original on 26 January 2014.

External links

• "Taxon profile: genus Tytthus Fieber, 1864". Biolib.
• "Tytthus" at the Encyclopedia of Life
• "Tytthus Fieber, 1864". Integrated Taxonomic Information System . Retrieved 26 January 2014.