Mizotrechus bellorum, Erwin, 2011

Erwin, Terry L., 2011, Rainforest understory beetles of the Neotropics, Mizotrechus Bates 1872, a generic synopsis with descriptions of new species from Central America and northern South America (Coleoptera, Carabidae, Perigonini), ZooKeys 145, pp. 79-128 : 86-87

Bells’ trough beetle Mizotrechus bellorum sp. n. Figs 2 25 40

Holotype.

Guyane, Saut Pararé, Arataie River, Nouragues Field Station, 51 m, 4.0378°N, 52.6725°W, 13 September 2009 (S Brule, PH Dalens, & E Poirier)(NMNH: ADP124890, male)

Derivation of specific epithet.

The epithet “bellorum” is an eponym, based on the family name of Ross and Joyce Bell, with a special thanks for a career that brought light to the rhysodine clade of very interesting beetles with colors and tough cuticle also found in adults of Mizotrechus species.

Proposed English vernacular name.

Bells’ trough beetle.

Diagnosis.

With the attributes of the genus as described above and medium sized for the genus as it is presently understood; adults have castaneous integument, except anterior parts of mandible, baso-lateral corner of labrum, and clypeal suture piceous. Frons at sides with evident rugae, punctulate. Occiput at sides with evident rugae, punctulate. Pronotum nearly quadrate, narrowed behind, with straight margins to hind angle, hind angle dentate, tooth small; base sparsely rugulose. Elytra broad and short, much wider than the width of pronotum across anterior third, and with only interneurs 1-3 moderately engraved, 4-8 evident yet shallowly impressed, more so toward margin, not punctate; margin behind humerus uneven, yet not serrate. Foreleg femur subdentate at the base of postero-ventral margin.

Description.

( Figs 2 , 25 ). Size: See Appendix 1. Medium sized for the genus, ABL = 6.9 mm, SBL = 5.87 mm, TW = 2.55 mm. Color: see diagnosis, above. Luster: Head, pronotum, and legs shiny, elytra slightly duller due to shallowly engraved slightly stretched microsculpture. Head: Labrum quadrate and apico-medially emarginate. Eye large, moderately convex. Gena moderately short, straight. Frons, occiput and gena glabrous. Prothorax: Narrow, quadrate, narrowed slightly toward base, margins not emarginate before hind angle, angle dentate, tooth small, margin moder ately explanate except wider at hind angle; surface punctulate, punctures widespread, glabrous. Pterothorax: Elytron moderately convex, disk flat, intervals flat, interneurs not punctate, apex moderately oblique and straight, sutural apex narrowly rounded. Metasternum sparsely setiferous in male. Legs: Normal in male; foreleg femur (as in Fig. 20 ) with a small obtuse tooth at basal third of postero-ventral margin; posterior trochanter narrowly acute at apex, about half the length of the femur. Abdomen: Abdominal sterna moderately setiferous; sternum IV of male with narrow and dense patch of decumbent setae. Male genitalia: Median lobe ( Fig. 25 ) elongate and robust with ostium moderately elongate, over half the length of the median lobe; apex a losp. n.tulate distal end less bent ventrad than in Mizotrechus dalensi and thicker in cross section, moderately curved in lateral aspect, ventral margin proximal to apex straight then evenly curved to apex; endophallus with complexly folded tracheal fields; phallobase hooded, not crested, opening more or less 30 degrees off axis with that of shaft. Parameres large, left a half longer than the right, both broadly rounded, asetose. Female genitalia: Unknown.

Dispersal potential.

These beetles are macropterous and capable of flight. They are moderately swift and agile runners.

Way of life.

The adult holotype was collected in a flight intercept trap in the rainforest understory. Adults are active in September, near the end of the dry season.

Other specimens examined.

None.

Geographic distribution.

( Fig. 40 ). This species is currently known only from the type locality in the lowlands of Guyane.

Figures

Plate 1. Digital Photo-illustrations, habitus, dorsal aspect: 1 Mizotrechus batesi sp. n., ABL = 5.9 mm, male holotype, ADP 124884; type locality. 2 Mizotrechus bellorum sp. n., ABL = 6.9 mm, male holotype, ADP 124890; type locality. 3 Mizotrechus belvedere sp. n., ABL = 7.2 mm, male holotype, ADP 129201; type locality. 4 Mizotrechus brulei sp. n., ABL = 6.7 mm, female paratype, ADP 124926; type locality.

Plate 6. Digital Photo-illustrations, anterior femur, ventral aspect: 19 Mizotrechus minutus sp. n., ADP 124966; type locality. 20 Mizotrechus dalensi sp. n., ADP 124896; type locality. 21 Mizotrechus chontalesensis sp. n., ADP 127181; type locality. 22 Mizotrechus edithpiafae sp. n., ADP 124948; type locality. 23 Mizotrechus brulei sp. n., ADP 129205; type locality. 24 Mizotrechus gorgona. sp. n., ADP 128622; type locality.

Plate 7. Digital Photo-illustrations, male genitalia, median lobe and parameres, left lateral, dorsal, and right lateral aspects: 25 Mizotrechus bellorum sp. n., ADP 124890; type locality. 26 Mizotrechus belvedere sp. n., ADP 129201; type locality. 27 Mizotrechus brulei sp. n., ADP 127159, Guyane, Montagne des Chevaux, Commune de Roura.

Figure 40. Distribution symbol map for known localities of Mizotrechus batesi, Mizotrechus bellorum, Mizotrechus belvedere, Mizotrechus brulei, Mizotrechus dalensi, Mizotrechus grossus, Mizotrechus marielaforetae, Mizotrechus minutus, Mizotrechus poirieri, Mizotrechus neblinensis, spp. n.