Dentridactylus truncatus, Baena-Bejarano & Heads, 2018

Baena-Bejarano, Nathalie & Heads, Sam W., 2018, First records of Dentridactylinae (Orthoptera: Tridactylidae) from Colombia, with description of two new species of Dentridactylus Günther, Zootaxa 4402 (3), pp. 575-584 : 579-582

Dentridactylus truncatus sp. nov.

Figs. 7–10

Holotype. Male (no. ICN 087977 ), COLOMBIA, Amazonas, PNN Amacayacu, Matamata , 3°23'S, 70°06'W, 150 m, M1123. 17.xii–2.i.2000, Col. A. Parente Leg . Specimen preserved in alcohol; deposited at Instituto de Ciencias Naturales , Universidad Nacional de Colombia, Bogotá .

Paratypes. Three specimens from same locality as holotype: (1) Male (no. ICN 093583 ) specimen preserved in alcohol; (2) Female (no. ICN 087911 ) 3°23'01''N, 70°06'01''W, 300 m, 6–12.vii.2000 . A Parente Nat. specimen preserved in alcohol; (3) Female (no. ICN 093584) 3°23'01''N, 70°06'01''W, 300 m, 6–12.vii.2000. A Parente Nat. specimen preserved in alcohol. Specimens deposited at same institution as holotype.

Diagnosis. The new species can be distinguish by the following combination of characters: [1] Epiproct with lateral lobes [2] lateral margin of epiproct concave, not indented

Description. Male (holotype). Body length 6.2 mm; interocular distance 0.9 mm; pronotum length 1.3 mm, pronotum width 1.7 mm; tegmina length 0.9 mm; metatarsus 0.7 mm. (n=1) ( Figs. 7–10 ).

Head brown. Lateral carinae extended from the occiput to the compound eyes without reaching the eyes. Medial carinae on the top of the head extended along half the length of the coronal suture. Epicranial suture present. Lateral ocelli rudimentary. Medial ocellus absent, a small groove in its place. Labrum rounded. Maxillary palp with five segments, last segment with strong setae. Labial palp with three segments, last segment with strong thick setae. Galea and lacinia elongate; lacinia heavily sclerotized and strong like a tooth; galea softer and flexible.

Antennae brown. 10-segmented. Scape wider and longer than pedicel. Flagellomere 1 longer than pedicel and flagellomere 2.

Thorax. Pronotum with patch of setae on both sides of anterior margin. Prosternum without lobe. Mesonotun (episternum) with a patch of setae. Tegmina short with subcostal vein thick. Alae absent. Forelegs brown, elongated coxa subquadrate with few hairs in the inner margin. Protrochanter short. Profemur inner margin with rows of hairs in the edges, external edge with longer setae. Protibiae distally extended with three strong spines, and densely covered with what it seems two types of setae, one long hair-like and the other strong spine-like. Protarsi with two tarsal segments; last segment with a pair of claws. Middle leg missing, brown coxa. Hind leg brown, trochanter absent; femur large, brown with a white vertical mark, anterior to the semilunar process; inner carinae, ventral and dorsal edge of femur dark black-brownish. Metatibia without swimming plates, with two dorsal rows of 12–13 spines outer and 12 inner, a pair of short subapical spurs is present, the spurs are asymmetrical with the external spur short and the inner spur twice the size, with an inner apical patch of setae. A pair of apical spurs with an inner apical group of setae are present; the spurs are twice longer than the inner subapical spurs. Metatarsi strong and as long as cerci, a terminal tooth and an outer subapical tooth is present followed by a row of minute teeth along the edge; inner dorsal edge with a row of setae clustered; ventral edge with one row of setae. The tip of spurs is reddish tooth-like and the same reddish coloration is observed in tibial rows of spines.

Abdomen. Brown. 10-segmented, segment 9 corresponded to the subgenital plate with rounded margin; the segment 10 is merged with the terminalia. Tergum 10th with a medial membranous groove drop-like, margin curved not extended or without lobes, a pair of setae is present near the posterior margin, each one in a corner of the membranous groove. Cerci two-segmented with setae. Brachium brown, cerci-like but shorter than cerci and covered with thicker setae. Brachium base densely covered with setae. Uncus 1-hooked. Epiproct with lateral lobes. Proximal margin with deep invagination, distal margin of epiproct triangular with setae. Phallus membranous without spikes ( Fig. 6 ).

Male variation. Body length 6.2 mm; interocular distance 0.9 mm; pronotum length 1.2–1.3 mm, pronotum width 1.7 mm; tegmina length 0.8–0.9 mm; metatarsus 0.7–0.9 mm. (n=2). Metatibia with two dorsal rows of 11– 13 spines outer and 10–12 inner.

Female. Body length 7.5–8.1 mm; interocular distance 0.9–1.0 mm; pronotum length 1.3–1.4 mm, pronotum width 1.8–2.0 mm; tegmina length 0.8–1.0 mm; metatarsus 0.9–1.0 mm. (n=2). Body similar to male, except for antennae brown and thinner. Foreleg tibiae distally extended with four strong spines, densely covered with thicker setae than male; two types of setae, one long hair-like and the other strong spine-like. Hind leg tibia with two dorsal rows of 11–14 spines outer and 13–14 inner. Abdomen brown. 10-segmented, segment 8 corresponded to the subgenital plate with rounded margin. Tergum 10th with a medial membranous groove drop-like, margin slightly projected rounded, 1–2 pairs of setae are present near the posterior margin, each one in a corner of the membranous groove; brown small mark at the margin of the tergum. Epiproct tongue-like with setae in distal margin, brown coloration at edges, with large triangular hyaline area.

Etymology. The specific epithet is from the Latin “ truncatus ” meaning “shortened” in reference to the truncate tegminal apex.

Distribution. Known from the type locality and from Leticia (also Amazonas).

Remarks. The new species is similar to other species of the genus in external morphology. However, it is distinguished from D. albisignatus by having a brown pronotum without white markings; from D. keyi by having the margin of tergite 10 entire, without tooth-like extensions. The new species differs from D. denticulatus by having the lateral margin of the epiproct entire, not indented. From D. raggei the females can be distinguished by the margin of the subgenital plate that is smoothly curved, and not produced apically. In common with D. quadratus , D. truncatus exhibits greater overall size than Australian species and the apex of the tegmen is blunt. However, D. truncatus differs from D. quadratus in the shape of the male epiproct which bears lateral lobes and less square-shaped. In addition, male tergite 10 is straight in D. truncatus and curved in D. quadratus . Female epiproct coloration is different between Colombian species. It is lighter in D. truncatus ( Fig. 12 ) having a triangular mid-hyaline area with brown coloration at the edges, yet is darker and more homogeneously brown in D. quadratus ( Fig. 11 ). Female antennomere 6 is longer than the scape and pedicel together in D. truncatus and shorter in D. quadratus .

Figures

FIGURES 7–10 Dentridactylus truncatus, sp. nov. holotype male. 7 Habitus in dorsal view. 8 Habitus in ventral view. 9 Subgenital plate in ventral view. 10 Terminalia of paratype male in dorsal view.

FIGURES5–6 Phallic complex.5 Dentridactylus quadratus, sp. nov. holotype.6 Dentridactylus truncatus, sp. nov. paratype.

FIGURES11–12 Dorsal view of female terminalia.11 Dentridactylus quadratus, sp. n. 12Dentridactylus truncatus, sp. n.