Espeson franiae, 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 : 339-340

Espeson franiae n. sp. ( Figs 12 a-e, 17E)

Type material:

Holotype, male: Mexico: Chiapas, Union Juárez (15°03'N, 92°04'W), NE slope of Volcan Tacaná , 2000 m elevation, male, Dec. 21, 1975, leg. H. Frania, #200-75 ( AMNH).

Diagnosis:

E. franiae is the largest Espeson species of the Neotropical region, actually known. Its darker reddish colouration is similar as in E. dybasi , E. mexicanus , E. hermani , and E. simplex . It resembles E. dybasi in the pronotal and elytral punctation, and in the shape and position of the circular pronotal impression. It can be distinguished from E. dybasi by the larger size and the narrower elytra. Whereas the ratio of pronotal to elytral width is 1.4 in E. franiae , E. mexicanus , E. simplex , and E. hermani , the ratio is 1.6 in E. dybasi . Abdominal tergite VIII of males and the aedeagus resembles those of E. simplex , but paramera in E. franiae are angulate in the middle and a pair of transparent spots is placed at base of tergite VIII.

Description:

Length: 2.7 mm. Colour: brown, elytra lighter reddish, legs dark yellow.

Head: 0.30 mm long, 0.43 mm wide; more or less globular in shape; widest at eyes and with rounded temples; fore-head triangular; setiferous punctation deep and dense; on average distance between punctures less than half as wide as diameter of punctures; with moderately wide impunctate midline; surface without microsculpture and polished.

Antennae slightly longer than head and pronotum combined; 2 nd antennomere globular, half as long as conical 3 rd antennomere; 4 th to 6 th antennomere more or less quadrate; following antennomeres slightly wider than long and slightly increasing in width with exception of 8 th antennomere; 8 th antennomere slightly smaller than 7 th and 9 th antennomeres.

Pronotum: 0.37 mm long, 0.45 mm wide; widest in anterior half; sides of anterior half rounded; in posterior half deeply emarginate; lateral margin in anterior half present, but not visible in dorsal aspect; setiferous punctation coarse and dense; punctures distinctly deeper and larger than

head; distance between punctures less than half as wide as diameter of punctures; surface without microsculpture and polished.

Elytra: 0.63 mm long, 0.65 mm wide; sides smoothly rounded from shoulders to posterior angles; anterior edge distinctly emarginate; posterior edge slightly emarginate; setiferous punctation irregular; size of punctures variable; fine micro-punctures between punctures of normal size and few larger and deeper punctures; on average distance between punctures as wide as diameter of punctures; surface without microsculpture and polished.

Abdomen on anterior segments III to V coriaceously punctate; density of punctation decreasing to posterior segments; segment VIII twice as long as preceding segments; posterior edge of tergite VIII deeply emarginate; at outer posterior angles with short stylus; with few long and black setae and more dense fine setation; at posterior emargination with transverse lighter band with longitudinal striae; at base of tergite VIII two lighter spots surrounded by darker circle.

Aedeagus with apical part of central lobe as long as basal part; apical part smoothly rounded; paramera with small transparent plate at apex; diameter of transparent plate not wider than apical short stylus; paramera with triangular prominence at middle.

Etymology:

The specific name refers to its collector H. Frania.

Figures

Figs 12-13: Espeson franiae (12), E. simplex (13); a: fore body, b: antenna, c: aedeagus, d: apex of paramera, e: abdominal tergite VIII of male (scale bar: a, b: 0.5 mm, c–e: 0.1 mm).