Diochus unicolor, Irmler, 2017

Irmler, Ulrich, 2017, A review of the Neotropical genus Diochus ERICHSON, 1840 (Coleoptera: Staphylinidae: Staphylininae), Beiträge Zur Entomologie = Contributions to Entomology 67 (1), pp. 1-62 : 8-9

publication ID

https://doi.org/ 10.21248/contrib.entomol.67.1.001-062

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scientific name

Diochus unicolor

sp. nov.

Diochus unicolor View in CoL spec. nov.


Figs 7A–C View Figs 6–9 , 38E View Fig , 41F View Figs 41

Type material: male Holotype: Suriname: Para, Cardina creek , 11 km SE Zanderij Airport (55°09.29'W, 5°23.36'N), 30 m elevation, collected by flight intercept trap, 19.–20.6.199, leg. Z.H. Falin & A. Gangadin, #SUR1F99 088 ( KNHM). GoogleMaps

Paratypes: Panama: Canal Zone, Frijoles train stop, sifted, leaf litter, male, 25.10.1975, leg. D.S. Chandler ( FMNH) ; Bolivia: Beni , Ilha Flores, Rio Iténez , 1 male, 3 females, 7.8.1964, leg. J.K. Bouseman & L. Lussenhop ( AMNH) ; Santa Cruz , 10 mi W Puerto Chuelo, UV light trap, male, 27.3.1978, leg. Marshall ( FMNH) ; Brazil: Goias, Sta. Isabel, R. Araguaia , Isla Bananal , at light, female, 27.10.– 4.11.1960, leg. B. Malkin ( FMNH) ; Paraguay: Paraguari, Sapucai (25°40'S, 56°55'W), 190 m elevation, male, 1.– 3.4.1994, leg. U. Drechsel ( UIC) GoogleMaps ; Dep. Central, San Lorenzo (25°20'S, 57°31'W), female, 9.2.1991, leg. U. Drechsel ( KNHM) GoogleMaps ; Villarrica, female, April , 1933, leg. Koller ( NMW) .

Diagnosis: Regarding the small size, D. unicolor resembles D. ashei and D. adisi of this group. It is mainly separated from these two species by the shorter eyes. EL: HL is only 0.21, wheres it is both 0.29 and 0.27 in D. ashei and D. adisi , respectively.

Description: Length: 3.0 mm. Colouration: light brown to yellow; head slightly darker brown; legs and antennae light yellow.

Head 0.41 mm long, 0.38 mm wide; eyes prominent; temples 2.6 times as long as eyes; EL: HL = 0.21; distinctly divergent to posterior angles; PW: EW = 1.22; posterior angles shortly rounded to approximately straight posterior margin; setiferous punctation moderately dense; narrow midline impunctate; along midline, irregular row of four setiferous punctures; supraocular area with irregular setiferous punctation; temples more densely punctate; clypeus without microsculpture; surface polished; vertex with distinct transversely striate microsculpture; slightly shiny.

Antennae as long as head and pronotum combined; first antennomere thicker than following antennomeres; triangular second antennomere more than twice as long as at apical width; conical third antennomere twice as long as apical width; length of following antennomeres decreasing; fourth antennomere slightly longer than wide; tenth antennomere quadrate; all antennomeres pubescent and with apical setae.

Pronotum 0.56 mm long, 0.42 mm wide; widest in anterior half; widely rounded in nearly semi-circular curve; posteriad slightly convergent to shortly rounded posterior angles; posterior margin straight; lateral margin fine; in dorsal aspect, visible in posterior half; setiferous punctation moderately dense; along impunctate midline with three pairs of setiferous punctures; interstice between anterior pair of punctures three times as wide as between posterior pairs of punctures; laterad four to five setiferous punctures; along lateral margin several setiferous punctures.

Elytra 0.53 mm long, 0.53 mm wide; sides slightly divergent to posterior margin; shoulders obtusely angulate; posterior margin deeply emarginate; emargination triangular; setiferous punctation in irregular rows; inner row of five punctures adjacent to suture line; two additional rows on disc; ground sculpture weakly coriaceous; surface slightly shiny.

Abdomen densely pubescent.

Aedeagus short and broad; seminal vesical of endophallus thick and oval; approximately half as long as total length of central lobe; inner basal duct looped; continued to coiled apical duct; paramere slender; with four long apical setae; without sensillae at shaft.

Spermatheca 0.37 mm long, 0.24 mm wide; oval; bursa copulatrix approximately in central position of coiled duct.

Etymology: The species name derives from the same Latin word meaning only one colour and refers to the light brown to yellowish colouration without any distinct darker parts.


The Educational Science Museum [=Kuwait Natural History Museum?]


Field Museum of Natural History


American Museum of Natural History


Naturhistorisches Museum, Wien













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