Espeson pecki, 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: 345-346

publication ID 10.21248/contrib.entomol.62.2.331-360


persistent identifier

treatment provided by


scientific name

Espeson pecki

n. sp.

Espeson pecki   n. sp. ( Figs 14 View Figs 14-15 a-e, 17A)

Type material:

Holotype, male: Mexico: Cordoba, Prov. Veracruz, tropical evergreen forest, Berlese , male, 7.8.1969, leg. J. Peck ( AMNH).  

Paratypes: 65 specimens with same data as holotype   ; 385 specimens with same data as holotype, but 4.8.1969; Cordoba, Paraje Nueve Nacimiento, tropical evergreen forest, Berlese   , 26 specimens, 8.1969, leg. S & J. Peck; San Blas, junction San Blas and Tepic roads   , 9 specimens, 4.8.1960, without collector information; Nuevo, Monterrey León, Chipinque Mesa (115°15.49'W, 25°35.14'N), forest leaf litter, 1 female, 22.6.1969, leg. S. & J. Peck; Tamaulipas, Gomez Farias, Rancho del Cielo , 1100 m elevation   , 1 female, 4.7.1969, leg. S. & J. Peck; Veracruz, Fortin (96°59.59'W, 18°53.49'W)   1 male, 15 females, 5.8.1969, leg. S. & J. Peck ( AMNH, UIC)   .


Compared with the small yellow species, E. titschacki   , and E. adisi   , E. pecki   is easily to identify by the extremely small eyes. The species is as small as E. titschacki   and both species are slightly smaller than E. adisi   . Antennae are slightly shorter than in E. titschacki   . In E. titschacki   antennae are as long as head and pronotum combined, whereas they are slightly shorter than pronotum in E. pecki   . Both species, E. pecki   and E. titschacki   , can be distinguished from E. adisi   by the presence of two deep impressions on the pronotum, whereas E. adisi   has no impression on pronotum. E. venezuelanus   that is also similar to these three species is slightly darker. In males, the deep emargination of abdominal tergite VIII resembles that in E. simplex   , but E. simplex   is much larger, and punctation of tergite VIII is denser. Furthermore, the semicircular large apical plates of paramera are unique in the Neotropical Espeson species.  


Length: 1.6 mm. Colour: yellow. Head: 0.20 mm long, 0.25 mm wide; eyes extremely small; only four or five ocellae; nearly invisible in dorsal aspect; temples twice as long as eyes and convexly prominent; fore-head straightly narrowed to more or less acute front edge of clypeus; setiferous punctation moderately dense and fine; on clypeus finer and denser than on lateral part of vertex; disc with impunctate midline; surface shiny; laterad with remains of weak microsculpture; disc polished.

Antennae nearly as long as head and pronotum combined; 1 st and 2 nd antennomere oblong, 3 rd conical; antennomeres 1 to 3 nearly equal in length; antennomere 4 and 5 more or less quadrate; following antennomeres wider than long; 8 th antennomere narrower and smaller than antennomeres 7 and 9; 10 th antennomere nearly twice as wide as long.

Pronotum: 0.23 mm long, 0.27 mm wide; with weak lateral margin; only visible in posterior half in dorsal aspect; deeply emarginate in posterior half; posterior edge only half as wide as width in anterior half; setiferous punctation deeper and coarser than on head; distance between punctures on average only half as wide as diameter of punctures; in anterior and posterior half each a small, but deep impression; surface shiny; laterad with remains of microsculpture, but surface mostly polished.

Elytra: 0.26 mm long, 0.33 mm wide; with setiferous punctation slightly weaker and sparser than on pronotum; with remains of microsculpture, but surface mostly polished and shiny.

Abdomen with coarser punctation on anterior segments than on distal segments; microsculpture slightly more distinct than on elytra and, thus, surface less shiny; tergite VIII of male deeply emarginate in middle and with long acute teeth at outer angles; sparsely punctate also at lateral margin.

Aedeagus with long and thick basal part; apical part more or less straight and only half as long as basal part; paramera with large apical plate of semicircular shape.


The specific name refers to its collector James Peck.


American Museum of Natural History