Mizotrechus dalensi, 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 : 91-92

Dalens’ trough beetle Mizotrechus dalensi sp. n. Figs 7 20 29 40 Plate 11

Holotype.

GUYANE, Saut Pararé, Arataie River, Nouragues Field Station, 51 m, 4.0378°N, 52.6725°W, 30 November 2009 (S Brule, PH Dalens, & E Poirier)(NMNH: ADP124894, male).

Derivation of specific epithet.

The epithet “dalensi” is an eponym, based on the family name of P.H. Dalens, whose team in Guyane has been collecting beetles using Flight Intercept Traps and capturing adults of many new species, such as this one.

Proposed English vernacular name.

Dalens’ 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 shallowly rugose and punctulate. Occiput shallowly rugose at sides and punctulate. Pronotum quadrate with lateral margins basally straight to slightly toothed hind angle; base moderately rugose. Elytra broad and moderately short, much wider than width of pronotum across anterior third, and with two well- impressed interneurs, the remainder shallower toward margin; margins behind humeri not serrulate. Foreleg femur dentate basally on postero-ventral margin.

Description.

( Figs 7 , 20 , 29 , Plate 11 ). Size: See Appendix 1. Medium-sized for genus, ABL = 7.6-8.2 mm, SBL = 6.40-7.09 mm, TW = 2.64-3.11 mm. Color: see diagnosis, above. Luster: Head, pronotum and legs shiny; elytra dull due to marked slightly stretched well-impressed microsculpture. Head: Labrum quadrate, apico-medially barely emarginate. Eye moderately large, moderately convex. Gena moderately long, straight. Frons, occiput, and gena glabrous. Prothorax: Broad, narrowed slightly toward base, margin beaded, not explanate except at hind angle; surface punctulate, punctures widespread, and with shallow yet evident transverse microsculpture, surface glabrous. Pterothorax: Elytron moderately convex, intervals flat, interneurs striate, not punctate, becoming shallower toward margin, apex slightly oblique, straight, sutural apex narrowly and slightly rounded. Metasternum sparsely setiferous in male. Legs: Normal in both sexes; foreleg femur ( Fig. 20 ) dentate at basal third on postero-ventral margin; posterior trochanter tapered to acute point in male, slightly acuminate in female, length half that of femur. Abdomen: Abdominal sterna moderately setiferous; sternum IV of male with narrow and dense patch of decumbent setae; sternum VII medially V-notched in male, U-notched in female. Male genitalia: Median lobe ( Fig. 29 ) 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 poirieri , moderately curved in lateral aspect, ventral margin proximal to apex straight then evenly curved to apex; endophallus with complexly folded tracheal fields; phallobase hooded and crested, opening more or less 40 degrees off axis of shaft. Parameres large, left a third longer than the right, both broadly rounded, asetose. Female genitalia: ( Plate 11 ). Ovipositor with broad laterotergite (lt) and two gonocoxites (gc 1, gc 2); gonocoxite 1 apico-laterally setose; gonocoxite 2 falcate, base (b) medium-size, narrow, blade (bl) elongate, with two dorsal ensiform setae (des), and one ventral ensiform seta (ves), all ensiform setae moderately long and robust; with ventral preapical nematiform setae (evident on A, hidden on B). Reproductive tract ( Plate 11A ) proximally with short, broad bursa copulatrix (bc), continuous at its distal end with common oviduct (co) and long robust spermatheca (sp), latter slightly narrowed distally; spermathecal gland (sg) bulbous; spermathecal gland duct (sgd) long, slender, attached to spermatheca at base of its broadened portion.

Dispersal potential.

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

Way of life.

The adults at four localities were collected in flight intercept traps in the rainforest understory. Adults are active in March and November, in both the rainy and dry seasons.

Other specimens examined.

Paratypes: Guyane, Saut Pararé, Arataie River, Nouragues Field Station, 51 m, 4.0378°N, 52.6725°W, 23 November 2009 (S Brule, PH Dalens, & E Poirier)(NMNH: ADP124896, male); Mount Itoupe, 570 m, 3.0148°N, 53.0721°W, 17 March 2010 (S Brule, PH Dalens, & E Poirier)(NMNH: ADP126485, male); Montagne des Chevaux, Commune de Roura, RN2 PK22, 90 m, 4.7127°N, 52.3966°W, 8 August 2010 (NMNH: ADP129203, female), 1 November 2009 (S Brule, PH Dalens, & E Poirier)(NMNH: ADP124956, female), Saül, Co mmune de Saül, Belvédère de Saül, 283-325 m, 4.7127°N, 52.3966°W, 20 December 2010 (NMNH: ADP127167, male), 4 January 2011 (S Brule, PH Dalens, & E Poirier)(NMNH: ADP124922, female), 36 km W Regina, Petite Montague Tortue, P17, 94 m, 4.3204°N, 52.2404°W, 23 June 2010 (G Lamarre)(NMNH: ADP127161, male).

Geographic distribution.

( Fig. 40 ). This species is currently known from five localities in the lowland and midland rainforests of Guyane.

Figures

Plate 2. Digital Photo-illustrations, habitus, dorsal aspect: 5 Mizotrechus chontalesensis sp. n., ABL = 7.1 mm, female holotype, ADP 127181; type locality. 6 Mizotrechus costaricensis sp. n., ABL = 8.4 mm, male holotype, ADP 128620; type locality. 7 Mizotrechus dalensi sp. n., ABL = 8.2 mm, male holotype, ADP 124894; type locality. 8 Mizotrechus edithpiafae sp. n., ABL = 8.4 mm, female holotype, ADP 124948; locality unknown.

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 8. Digital Photo-illustration, male genitalia, median lobe and parameres, left lateral, dorsal, and right lateral aspects: 28 Mizotrechus costaricensis sp. n., ADP 128620: type locality. 29 Mizotrechus dalensi sp. n., ADP 129203, Guyane, Saut Parare, Arataie River, Nouragues Field Station. 30 Mizotrechus edithpiafae sp. n., ADP 129203; Ger? locality (see text).

Plate 11. Figure 37. Digital Photo-illustration, female genitalia: Mizotrechus dalensi sp. n., ADP 127161; Petite Montague Tortue, Guyane. A. Dorsal aspect. Legend, bc, bursa copulatrix; co, common oviduct; sg, spermathecal gland; sgd, spermathecal gland duct; sp, spermatheca. dorsal aspect; vc, villous canal; lt, laterotergite; gc 1, gonocoxite 1; gc 2, gonocoxite 2. B. Gonocoxite 2, dorsal aspect: Legend, b, base of gonocoxite 2; bl, blade of gonocoxite 2; des, dorsal ensiform seta; ves, ventral ensiform setae.

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.