Batriscydmaenus tishechkini Parker and Owens, 2018

Parker, Joseph & Owens, Brittany, 2018, Batriscydmaenus Parker and Owens, New Genus, and Convergent Evolution of a “ Reductive ” Ecomorph in Socially Symbiotic Pselaphinae (Coleoptera: Staphylinidae), The Coleopterists Bulletin 72 (2), pp. 219-229 : 223-224

publication ID 10.1649/0010-065X-72.2.219

publication LSID


persistent identifier

taxon LSID

treatment provided by


scientific name

Batriscydmaenus tishechkini Parker and Owens

new species

Batriscydmaenus tishechkini Parker and Owens , new species

Type Material. Holotype ³: PANAMA: Colón Pr. San Lorenzo Forest 9°17′N 79°58′W. Forest litter, Winkler extraction IBISCA site B1. W 12558 View Materials // 10.x.2003. A.Dejean, G.Orivel, B.Cobrara, H.-P. Aberlenc & M.Leponce GoogleMaps . Paratypes (5): ³ PANAMA: Colón Prov. San Lorenzo Forest , STRI crane site. 9°17′N 79°58′W FIT-C3-17. 21-24 May 2004 A.K.Tishechkin. AT — 522; ³ GoogleMaps PANAMA: Colón Prov. San Lorenzo Forest . 9°17′N 79°58′W. F.I. T., 1.3m 14d FL-C281.3a. 17.x.2003 R. Didham, L. Fagan. IBISCA; ♀ GoogleMaps PANAMA: Colón Prov. San Lorenzo Forest , STRI crane site. 9°17′N 79°58′W FIT-I3-15. 15-17 May 2004 A.K. Tishechkin. IBISCA’04; ♀ PANAMA GoogleMaps : Colón Prov. San Lorenzo Forest , STRI crane site. 9°17′N 79° 8′W FIT-B3- 14. 20-21 May 2004 A.K. Tishechkin. IBISCA’04; ³ PANAMA GoogleMaps : Colón Prov. San Lorenzo Forest. 9°17′N 79°58′W. F.I. T., 1.3m 10d FL-C1A1.3b. 23. x.2003 R. Didham, L.Fagan. IBISCA. The male holotype, two male paratypes, and one female paratype are deposited in Field Museum of Natural History ( FMNH), Chicago, IL, USA GoogleMaps . A male and female paratype are held at the Louisiana State Arthropod Museum ( LSAM), Baton Rouge, LA, USA .

Diagnosis. As for the genus, additionally with vestiture of regularly spaced, spatulate setae on dorsal surface, and aedeagus with narrow distal process and patches of erect setae on distal surface.

Description. Holotype male body length 1.57 mm ( Fig. 1A, B View Fig ). Upper body surface shiny and glabrous except for sparse but regularly spaced large, suberect, spatulate setae ( Figs. 1A, B View Fig , 2A, B, D, D’ View Fig ). Body and antenna light reddish brown, appendages and maxillary palpi orange-yellow ( Fig. 1A, B View Fig ). Head: Moderately transverse ( Figs 1A View Fig ; 2B View Fig ). Integument smooth, shiny; dorsal surface with evenly spaced, spatulate setae; ventral surface with dense vestiture of simple, closely spaced setae. Vertex gently convex, smooth, lacking foveae, sulci, or carinae. Eye small, semi-circular, composed of approximately 45 facets ( Fig. 2A View Fig ). Postocular margins longer than eye length, gently rounded, narrowing from eyes towards base. Antennomeres 1–3 longer than wide; 3–10 subrectangular, about as long as wide; 11 largest ( Fig. 2A View Fig ). Thorax: Pronotum slightly wider than long, widest point at about 1/3 length; lateral margin rounded; disc smoothly shiny with evenly spaced, spatulate setae ( Figs. 1A View Fig , 2D View Fig ). Mesoventrite with fine lattice microsculpture medially ( Fig. 2E View Fig ). Metaventrite smoothly shiny, vestiture of simple, closely spaced setae becoming denser in area between meso- and metacoxae. Abdomen: Wider than long, narrowed posteriorly ( Fig. 1A, B View Fig ). Aedeagus with dorsal diaphragm large, centrally positioned within disc; parameres absent; distal process narrow; distal surface with patches of short, erect setae ( Fig. 3D View Fig ). Elytra: Subtrapezoidal ( Fig. 1A View Fig ), base much narrower than apex; foveae and striae absent; surface smoothly shiny, covered with evenly spaced, spatulate setae ( Fig. 1A, B View Fig ). Legs: Simple, elongate, unmodified except protibia with transverse sulcus in apical third.

Female. Externally similar to male. Eye slightly smaller, approximately 25 facets. Lacking transverse sulcus on protibia.

Etymology. The specific name honors our colleague and friend Alexey Tishechkin, histerid expert and myrmecophile enthusiast, who collected several specimens of the type series.

Biological Information. All specimens were collected by either flight intercept traps or a Winkler extractor, so the biology of the species is unknown. However, we think it highly likely that B. tishechkini is a myrmecophile or possibly a termitophile based on a suite of morphological features. The extensive loss of foveae, sulci, and striae to produce a smooth cuticle is a trait common to many inquilinous Pselaphinae ( Chandler 2001) . The spatulate setae closely match the form of known pselaphine myrmecophiles such as the trogastrine Jubogaster Parker and Maruyama ( Parker and Maruyama 2013) and some myrmecophilous aleocharines such as Phyllodinarda Wasmann. The robust, nearly moniliform antennae, composed of compact antennomeres, are also a feature of numerous pselaphine myrmecophiles and termitophiles ( Chandler 2001). Moreover, B. tishechkini is strikingly similar in appearance to Loeblibatrus yunnanus Yin , a myrmecophile of Ectomomyrmex Mayr in China ( Yin 2018). In the absence of molecular data from Loeblibatrus , we presently hypothesize that this close similarity is the outcome of convergent evolution in response to selection inside social insect colonies, rather than from shared ancestry.

Comments. No further specimens of this genus were recovered despite searching in the following museum collections that have extensive holdings of Neotropical pselaphine material: FMNH, American Museum of Natural History, New York , Snow Entomological Museum Collection, Kansas, Natural History Museum, London, UK, and the personal collection of Donald Chandler ( University of New Hampshire) .


Tavera, Department of Geology and Geophysics


Departamento de Geologia, Universidad de Chile


Field Museum of Natural History


Louisiana State Arthropod Museum