Geocharidius balini, Sokolov, Igor M. & Kavanaugh, David H., 2014

Sokolov, Igor M. & Kavanaugh, David H., 2014, The integripennis species group of Geocharidius Jeannel, 1963 (Carabidae, Bembidiini, Anillina) from Nuclear Central America: a taxonomic review with notes about biogeography and speciation, ZooKeys 443, pp. 61-118 : 75-76

Taxon classification Animalia Coleoptera Carabidae

Geocharidius balini sp. n. Figs 1A, D, G, 5B, 7F, 12F, 13 O–Q, 16E, 17E, 22, 23

Type material.

HOLOTYPE, a male, in KUNHM, point-mounted, labeled: \ GUATEMALA: Suchitepéquez: 4km S Vol. Atitlán, 14.54915- 91.19055 ± 200m, 1625m, 15-VI-2009 ex sifted leaf litter, cloud forest, LLAMA09 Wa-B-09-1-all \ KUNHM \ HOLOTYPE Geocharidius balini Sokolov and Kavanaugh 2014 [red label] \. PARATYPES: A total of 117 specimens (3 males and 2 females were dissected), deposited in CAS and KUNHM; 99 specimens labeled same as holotype; 10 specimens labeled: \ GUATEMALA: Suchitepéquez: 4km S Vol. Atitlán, 14.55103- 91.19350 ± 306m, 1750m, 15-VI-2009 ex sifted leaf litter, cloud forest, LLAMA09 Wm-B-09-2-01 \ KUNHM \; 7 specimens labeled: \ GUATEMALA: Suchitepéquez: 4km S Vol. Atitlán, 14.55311- 91.19337 ± 35m, 1750m, 15-VI-2009 ex sifted leaf litter, cloud forest, LLAMA09 Wm-B-09-2-02 \ KUNHM \; 1 specimen labeled: \ GUATEMALA: Jalapa: 4km E Mataquescuintla, 14.53257 -90.15253 ± 200m, 2400m, 1-VI-2009, ex. sifted leaf litter, cloud forest, LLAMA09 Wa-B-07-2-all \ KUNHM \.

Type locality.

Guatemala, Suchitepéquez, 4 km S of Volcan Atitlán.

Etymology.

The specific epithet is a Latinized eponym in the genitive case, and is based on the given name of the dwarf Balin, a refounder of the underground kingdom of Moria, one of Thorin Oakenshield’s Company of Dwarves who had accompanied Bilbo Baggins on the Quest of Erebor in the book "The Hobbit, or There and Back Again" by J.R.R.Tolkien.

Recognition.

Adults of this new species are distinguished from those of other members of the integripennis species group externally by their small size and the presence of microsculpture on the pronotum and internally by the structure of the median lobe of males and the shape of spermatheca of females.

Description.

Size. Small to medium for genus (SBL range 1.22-1.34 mm, mean 1.27 ± 0.040 mm, n=26).

Habitus. Body form (Fig. 12F) moderately convex, elongate ovoid, general proportions (WE/SBL 0.38 ± 0.008) and proportions of head (WH/WPm 0.72 ± 0.013) and pronotum (WPm/WE 0.78 ± 0.017) average for group.

Color. Body brunneorufous, appendages testaceous.

Microsculpture. Mesh pattern of irregularly isodiametric sculpticells present over all dorsal surfaces of head, pronotum and elytra. Proepisternum with evident microsculpture.

Head (Fig. 1A).

Mouthparts. Maxillae and labium (Fig. 5B)

Prothorax. Pronotum (Fig. 1D) moderately transverse (WPm/LP 1.26 ± 0.022), with lateral margins moderately constricted posteriorly (WPm/WPp 1.32 ± 0.021). Posterior angles obtuse (110-120°). Widths between anterior and posterior angles of equal length (WPa/WPp 0.99 ± 0.022).

Elytra (Fig. 1G). Moderately convex, slightly depressed along suture, moderately narrow (WE/LE 0.64 ± 0.018), without traces of striae. Humeri rounded, in outline forming right angle with longitudinal axis of body. Lateral margins convex, evenly divergent at basal third, evenly rounded to apex in apical third.

Legs. Metatibia (Fig. 7F)

Male genitalia. Median lobe (Fig. 13O) with shaft short and broad and apex of moderate size and rounded. Ventral margin greatly enlarged and convex, with numerous poriferous canals. Dorsal sclerites of internal sac of peculiar shape, in form of anastomosing short figs, connected in apical and basal thirds, pointed apically as a short blade. Right paramere long and narrow (Fig. 13Q). Left paramere with long and narrow apical constriction (Fig. 13P). Ring sclerite with handle almost rectangularly rounded, slightly asymmetrical (Fig. 16E).

Female internal genitalia. Spermatheca sclerotized, fusiform with apical bulb enlargement, straight, with cornu long and nodulus short (Fig. 17E). Lengths of spermathecal gland and spermatheca equal. Spermathecal duct not coiled.

Geographical distribution.

This species is known only from two localities remote from each other: one situated on the southern slopes of volcano Agua in the Suchitepéquez Department, and the other situated on the northern slopes of a former twinned volcano, remains of which form the caldera of Laguna de Ayarza, in Jalapa Department. Both localities are in the volcanic chain of the Guatemalan Cordillera (Fig. 22, green diamonds).

Way of life.

Specimens were collected by sifting cloud forest litter at middle (1600-1750 m) to high elevations (2400 m).

Relationships.

The shapes of handle of ring sclerite (Fig. 16E) and of the spermatheca (Fig. 17E) suggest that this species is closely related to Geocharidius jalapensis (Figs 16D, 17D, described below.