Tachysbembix sirena Erwin

Erwin, Terry L., 2004, The beetle family Carabidae of Costa Rica and Panamá: Descriptions of four new genera and six new species with notes on their way of life (Insecta: Coleoptera), Zootaxa 537, pp. 1-18 : 4-6

Tachysbembix sirena Erwin , new species

( Figs. 1 , 2 , 13 )

Holotype. Male. COSTA RICA: Osa, P.N. Corcovado, Llorona, 20km N Estación Sirena , 1–100 m, 08º 37’ N 083º 42’ W, LS 270500,508300, January (R.W. Matthews & J.R. Matthews)( INBio: ADP103930).

Derivation of specific name. The specific epithet, sirena , is used as a noun in apposition and is based on the Estación Sirena in Corcovado National Park in reference to one of the places near which members of this species are found and the way of life of all species in this new genus, that is near the ocean where the songs of Sirens can be heard on foggy nights.

Common name. Sirena cream­colored seaside carabid.

Diagnosis. As described for genus and differs from the other known species of this genus in Costa Rica by the infuscated anterior and posterior margins of the pronotum, large maculation of the elytra disc, and the relatively longer elytra in relation to the length of the pronotum. (Ratio: elytra/pronotum = 3.47)

Description. ( Fig. 1 ). Size small: ABL = 3.7 to 3.9 mm, SBL = 3.5 to 3.7 mm, TW = 1.3 mm. Color: Testaceous except most of elytral disc which is diffusely infuscated. Luster: Surface dull. Microsculpture: Microsculpture isodiametric, granulate. Head: Large, about as wide as pronotum; frontal furrow absent; eyes large, hemispheric. Prothorax: Transverse, convex, side margin with small dent near base, hind angle absent, margin narrowly reflexed. Pterothorax: Mesepisternum multisulcate along anterior margin. Metathorax with fully developed flight wings. Elytra with interneurs 1 and 8 well impressed, 2–7 nearly effaced, traced in part by small punctures. Legs: Normal for Tachyina . Abdomen: Normal for Tachyina . Male genitalia: Aedeagus — phallus narrow, slightly arcuate, endophallus without armature, left paramere markedly elongate, narrow, unisetose, right paramere short, broader than left paramere, bisetose ( Fig. 2 ).

Dispersal potential. The wings are fully developed and the two known specimens flew to black light, thus it is likely that this species is a moderate to strong flyer.

Way of life. The three records here and information associated with those specimens from the five undescribed species I have studied suggest that the beetles of this genus live near the sea on lightly­colored sandy substrate. This suggestion is support by the adult coloration and their granular­isodiametric microsculpture which is common in sea shore species, such as Thalassotrechus barbarae (Horn) , Bembidion puritanum Hayward , Cillenus palosverdes (Kavanaugh & Erwin) , and Bembidion tigrinum LeConte , as well as some undescribed Tachys spp. from the intertidal zone of Baja California.

Other specimens examined. Paratypes: 2 females (Guanacaste, Nandayure, Estero Jabilla, sea level, 10º 02’ N 085º 11’ W, LN 199225,395300, December (W. Porras, #73830) (INB0003718766, INB0003718765).

Geographic distribution. ( Fig. 13 ). Known only from the pacific coast of Costa Rica. Notes. The specimens collected by Parataxonomist Wendy Porras were attracted to her blacklight.

Figures

FIGURE 1. Dorsal habitus of Tachysbembix sirena Erwin new species. FIGURE 3. Dorsal habitus of Tachysbembix wendyporrasae Erwin new species. FIGURE 5. Dorsal habitus of Pseudophorticus puncticollis Erwin new species. FIGURE 7. Dorsal habitus of Guatemalteca virgen Erwin new species.

FIGURE 2. Aedeagus, dorsal, ventral, left lateral aspects of Tachysbembix sirena Erwin n. sp.

FIGURE 13. Geographical distribution map of the new taxa in Costa Rica and Panamá: Tachysbembix sirena Erwin new species (solid circle —), Tachysbembix wendyporrasae Erwin new species (open circle —), Pseudophorticus puncticollis Erwin new species (open box —), Guatemalteca virgen Erwin new species (diamond —), Valeriaaschero flora Erwin new species (star —), V aleriaaschero nigrita Erwin new species (triangle —). Note star () in Panamá (see text).