Espeson dybasi, Irmler, 2012

Irmler, U., 2012, The Neotropical species of the genera Pseudespeson L, 1994 and Espeson S, 1882 (Coleoptera: Staphylinidae: Osoriinae), Beiträge Zur Entomologie = Contributions to Entomology 62 (2), pp. 331-360 : 337-338

publication ID 10.21248/contrib.entomol.62.2.331-360


persistent identifier

treatment provided by


scientific name

Espeson dybasi

n. sp.

Espeson dybasi n. sp. ( Figs 15 View Figs 14-15 a-e, 17B)

Type material:

Holotype, male: Panama: Chiriqui, Finca Palo Santo , 5.3.1959, leg. H. S. Dybas ( AMNH).

Paratypes: 179 specimens with same date as holotype; NW Volcán de Chiriqui , litter near stream (82°40'32"W, 8°49'19"N), 1450 m elevation GoogleMaps , 4 males, 6 females, 16.5.2001, 1 female, 17.5.2001, leg. L. Herman; 25.7 km NW Volcán de Chiriqui , litter near stream (82°46'24"W, 8°50'06"N), 1150 m elevation GoogleMaps , 3 females, 27.12.2001, leg. L. Herman; 11.5 km E Volcán de Chiriqui, Rio Sereno , tree fall litter in forest (82°46'24"W, 8°50'05"N), 1150 m elevation GoogleMaps , 1 female, 26.12.2001, leg. L. Herman; Panama, road to Cerro Campana , litter near seep (79°54'50"W, 8°41'20"N), 645 m elevation GoogleMaps , 4 specimens, 1.1.2002, leg. L. Herman; road to Cerro Campana , litter near stream (82°55'12"W, 8°41',00"N), 730 m elevation , 3 specimens, 22.12.2001, leg. L. Herman; Costa Rica: Puntarenas, 35 km NE San Vito, nr. Las Alturas (82°50.08'W, 8°56.16'N), trail to Cerro Echandi, 1950 m elevation, beyond trail marker 30, litter near stream GoogleMaps , 78 specimens, 19.3.1991, leg. L. Herman; 7.5 km on trail to Cerro Echandi, Rio Bella Vista , litter near stream , 34 specimens, 21.3.1991, leg. L. Herman; Las Cruces Botanical Garden, near San Vito (82°57.19W, 8°47.28'N), 1066 m elevation GoogleMaps , 1 specimen, 27.2.1985, leg. L. Herman; Alajuela, nr. Poasito (84°11.35'W, 10°10.09N), 6.6 km W Jct. Rt. 126(9) & 120, 2011 m elevation, Volcán Poas, litter near stream GoogleMaps , 6 females, 16.3.1991, leg. L. Herman; Cartago, 16.5 km N Capellades (83°47.07'W, 9°55.27'N), Rd. to Volcán de Turrialba , 2538 m elevation, leaf litter under hummock in pasture GoogleMaps , 7 specimens, 14.3.1991, leg. Herman; Heredia, 2 km S Sacramento, Rd. to Volcán Barba, 2011 m elevation, litter near stream , 1 male, 15.3.1991, leg. L. Herman; La Selva Biol. Station , 1 specimen, 18.2.1985, leg. L. Herman; 27 km N Heredia (83°59'W, 10°39'W), Rt 9, 1828 m elevation , 1 specimen, 9.2.1985, leg. L. Herman; Ecuador: Pichincha, 18-20 km NE Alluriquin, old Quito-Sto Domingo rd. , 1460 m elevation, litter , 1 specimen, 21.10.1988, leg. L. Herman; 1950 m elevation, litter, 1 specimen, 23.10.1988; 43 km N, Las Palmeras, old Qt Sto. Dgo. rd. km 59, litter , 2 females, 23.10.1988, leg. L. Herman; Napo, 7 km W Baeza , litter, 2400 m elevation , 1 male, 31.10.1988, leg. L. Herman ( AMNH, UIC) .


The species resembles E. mexicanus and E. simplex in size and colour. It can be easily differentiated from these two species by the elongate antennae. Whereas in E. mexicanus and E. simplex antennae are only slightly longer than head and pronotum combined, antennae of E. dybasi are as long as head plus pronotum plus half of elytra. Moreover, the shape of the elytra also differs distinctly between E. dybasi and both E. mexicanus and E. simplex , respectively. Width of elytra of E. dybasi is more than 1.5 times as wide as pronotum, whereas it is only 1.3 times as wide in E. mexicanus and E. simplex . In all three species tergite VIII is slightly emarginate at posterior edge. In E. mexicanus the emargination is weak and smooth without distinct acute prominences at outer posterior angles. In E. dybasi a short stylus is placed at posterior angles, while an acute teeth is present in E. simplex .


Length: 2.3 mm. Colour: brown; elytra and antennae red; legs yellow.

Head: 0.30 mm long, 0.40 mm wide; eyes distinctly prominent; temples half as long as eyes; smoothly rounded to neck; fore-head distinctly narrowed to acute front edge of clypeus; densely and deeply punctate; distance between setiferous punctures on average less than 1/2 of diameter of punctures; vertex with impunctate midline; without microsculpture; surface shiny.

Antennae longer than head and pronotum combined; 2 nd antennomere short; 3 rd conical antennomere longer than 2 nd; 3 rd to 7 th antennomeres longer than wide; 8 th antennomere slightly narrower and shorter than preceding and following antennomeres.

Pronotum: 0.38 mm long, 0.38 mm wide; smoothly rounded in anterior half; distinctly emarginate in posterior half; lateral margin not visible in dorsal aspect; setiferous punctures dense and coarse; with narrow impunctate midline; on average distance between punctures half as wide as diameter of punctures; with small, but deep circular impression in central position of posterior half.

Elytra: 0.55 mm long, 0.60 mm wide; sides smoothly rounded; widest in posterior third; setiferous punctation distinctly sparser and weaker than on pronotum; distance between punctures at least as wide as diameter of punctures, but on average distinctly wider.

Abdomen with abdominal tergite III densely and deeply punctate; distance between punctures 1/2 as wide as diameter of punctures; density of punctation decreasing from tergite III to tergite VII; distance between punctures on tergite VII 2 to 3 times as wide as diameter of punctures; abdominal tergite VIII widely emarginate and with acute angles; on top of each acute angle a short stylus; at base of tergite VIII two setiferous pores within irregular dark spots.

Aedeagus with more or less straight central lobe; paramera straight and with small irregular plate at apex.


The specific name refers to the name of its first collector Dr. H. S. Dybas.


American Museum of Natural History