Rueckeria, Arriaga-Varela, Emmanuel, Tomaszewska, Wioletta, Huo, Lizhi & Seidel, Matthias, 2018

Arriaga-Varela, Emmanuel, Tomaszewska, Wioletta, Huo, Lizhi & Seidel, Matthias, 2018, On Neotropical Merophysiinae with descriptions of a new genus and new species (Coleoptera, Endomychidae), ZooKeys 736, pp. 1-41 : 11-14

Rueckeria gen. n. Figs 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21

Type species.

Rueckeria inecol sp. n.

Etymology.

This genus is dedicated to Dr. Wolfgang Rücker, German coleopterist, who has devoted many years of his life to the study of merophysiine beetles.

Gender feminine.

Diagnosis.

Rueckeria can be easily distinguished from other Neotropical Merophysiinae by the following combination of characters: antenna 10-segmented with 1-segmented club (Fig. 7e); antennal grooves on head absent or indistinct (Figs 16a, 17a, 18a, 19b, 20a); pronotum with lateral margins narrowly bordered and weakly crenulate (Figs 16c, 17b, 18e, 19b, d, 20b, c); metaventrite without postcoxal lines (Fig. 7f); abdominal ventrite 1 with arcuate, closed postcoxal lines (Figs 7k, 12g, 16f, 17f, 18g, 19g); hind wings absent. Rueckeria is most similar to Lycoperdinella and Holoparamecus but from Lycoperdinella it can be differentiated by the lateral margins of the pronotum at most weakly crenulate (coarsely crenulate in Lycoperdinella ), elytra with anterolateral corners simple (Figs 16d, 17d) (with hooked tooth on each elytron in Lycoperdinella ), postcoxal lines present on abdominal ventrite 1 (postcoxal lines absent in Lycoperdinella ), longer and more slender antennae, the body covered with much shorter setae (long setae in Lycoperdinella ) and the hind wings always absent. From Holoparamecus , Rueckeria can be separated by having lateral margins of the pronotum bordered (smooth in Holoparamecus ), pronotum narrower near base but not distinctly constricted basally as in Holoparamecus , antenna with 1-segmented club (2-segmented club present in Holoparamecus ) and postcoxal lines present on abdominal ventrite 1 (postcoxal lines absent in Holoparamecus ).

Description.

Length 1.3-2.2 mm. Body elongate, approx. 2.0 times longer than wide, weakly convex, 2.8-3.3 times as long as high; shiny, smooth, covered with sparse and short pale setae. Color light brown to black.

Head (Fig. 7e) deeply retracted in prothorax (Fig. 15b), slightly wider than long; sparsely and moderately densely punctate. Gular sutures subparallel, widely separated. Eyes very small, oval, coarsely faceted, composed of 16-18 facets (Fig. 18a). Antennal sockets concealed by sides of frons, not visible from above; antennal grooves absent. Antenna moderately long (Figs 7e, 18c, 19c), surpassing base of pronotum, composed of 10 antennomeres with club formed by terminal antennomere which is large, inflated, subtriagular, obliquely truncate at apex. Frontoclypeal suture weakly arcuate (Fig. 7e). Clypeus transverse, flat, convergent anteriorly. Labrum (Fig. 7a) subquadrate, with rounded anterolateral corners, truncate apically, with submembranous apex, punctate, covered with sparse, long setae; tormae with mesal arms recurved posteriorly; labral rods absent. Mandible (Fig. 7c) with two apical teeth and with four smaller subapical teeth getting subsequently smaller posteriorly; prostheca covered with digitiform setae on anterior third getting thiner and shorter toward posterior 2/3; mola large, sclerotized; submola small, membranous. Maxilla (Fig. 7b) with palpomere 1 and 3 very short; palpomere 2 large and swollen, approx. twice as long as palpomere 3; terminal palpomere 1.5 times as long as 2 and 3 palpomeres combined, narrow, tapering, apex obliquely truncate to weakly rounded; galea moderately broad, twice as broad as lacinia, with long, broad, apical spine-like setae; lacina elongate, with spine-like setae on apical half. Labium (Fig. 7d) with palpomere 1 very small; palpomere 2 largest, oval, inflated; terminal palpomere subquadrate, truncate at apex. Mentum subquadrate (Figs 16b, 17a, 18a, 19b, 20a), with produced anterior angles; finely punctate, glabrous. Prementum subquadrate, sclerotized, with apically expanded, membranous ligula. Tentorium (Fig. 7e) with anterior arms fused medially and widely divergent anteriorly; corpotentorium absent.

Prothorax. Pronotum (Figs 16c, 17b, 18b, 19e, 20b) weakly transverse, widest at anterior 1/4; pronotal surface finely and sparsely punctate; lateral edges narrowly bordered, weakly crenulate, arcuately widening at anterior 1/4, and almost parallel at basal 1/4; anterior margin curved with slightly projected rounded angles; posterior angles almost right-angled. Pronotal disc weakly convex. Pronotal base with an impression composed of two longitudinal sharply defined, slightly convergent sulci reaching almost anterior third, and a pair of deep transverse depressions/sulci. Anterior transverse sulcus flanked by one small deep fovea on each side, fovea sometimes absent (Fig. 20c); area between transverse sulci convex, basal sulcus not reaching lateral sulci, provided with large, shallow foveate punctures. Prosternal process (Figs 16e, 17e) broad, approx. as wide as coxal diameter, with raised margins; extending posteriorly beyond front coxae. Procoxa circular in outline its cavity externally open behind, internally closed; trochantin concealed.

Meso- and metathorax. Mesonotum (Fig. 7h) sclerotized; scutellar shield small, strongly transverse, widely rounded apically, partially covered by base of pronotum. Mesoventrite (Figs 7f, 16e, 17e) carinate at middle; intercoxal process moderately elongate, rather broadly separates mesocoxae (slightly narrower than coxal diameter) reaching half of its length. Mesoventrite fused with mesanepisternum (trace of suture visible). Mesocoxe weakly oval in outline, its cavity narrowly closed outwardly by sterna; trochantin concealed. Meso-metaventral junction of straight-line type, without internal knobs. Elytron elongate, convex, irregularly and moderately finely punctate (Fig. 18e), border at anterolateral corner without teeth (Figs 16d, 17d); epipleuron narrow, incomplete at apex. Sutural stria sharply defined (Fig. 18e), complete, widest at mid length, then weakly converging towards elytral apex. Metaventrite (Figs 7f, 16e, 18f, 20d) transverse, twice as long as mesoventrite, weakly convex; anterior margin thick, with postcoxal longitudinal ridges reaching between anterior 1/3 to 2/5; discrimen very short. Metacoxae transversely oval, widely separated. Metendosternite with very short stalk and moderately widely separated anterior tendons. Hind wing absent.

Legs. Trochanter moderately elongate (Fig. 7j); trochanterofemoral attachment oblique. Femur widest near middle of its length, more than twice as wide as tibia, sparsely setose; tibia and tarsus covered with long, dense setae. Tibia narrow, straight or slightly bent inwards, continuously weakly widened distally or with abrupt wider part at distal third, without apical spurs. Tarsal formula 3-3-3 in both sexes (Fig. 17d): tarsomere 1, 1.5 times longer than 2; tarsomere 3 slightly longer than remaining tarsomeres combined. Claws simple. Empodium very small.

Abdomen (Figs 7k, 12g, 16f, 17f, 18g, 19g) with five freely articulated ventrites; ventrite 1 slightly longer than three following ventrites together, with arcuate, complete postcoxal lines; ventrites 2-4 almost equal in length; ventrite 5 long, acuminate, approx. as long or shorter than ventrites 3-4 together.

Aedeagus (Figs 8 d–f, 9 d–f, 10 d–f, 11 d–f, 12 d–f) resting on its side when retracted. Median lobe stout, with basal 2/3 strongly to weakly curved. Tegmen large, slightly shorter to 1.5 times longer than median lobe; parameres fused; tegminal strut absent or present.

Female genitalia (Figs 8g, 9g, 10g, 11g). Ovipositor weakly sclerotized, with coxites elongate; styli well developed or vestigial, placed apically. Spermatheca moderately large, elongate oval, submembranous; sperm duct moderately long, slender, membranous with short part connected to spermatheca sclerotized; accessory gland small membranous, elongate.

Distribution.

Mexico: Hidalgo, Querétaro, Veracruz (Fig. 21).