Dentridactylus quadratus, 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 : 576-579

Dentridactylus quadratus sp. nov.

FIGURES 1–4

Holotype. Male (no. ICN 088003 ), COLOMBIA, Putumayo, Orito, Vda Libano, predio UMIYAC 00°40'53.8''N, 077°02'07.2''W, 850 m, 8–14.iii.2003, Col. I. Giraldo, F. Quevedo y com. Indígenas Siona, Kofanes e Ingas. Colecta Winkle. Specimen preserved in alcohol; deposited at Instituto de Ciencias Naturales , Universidad Nacional de Colombia , Bogotá .

Paratype. Male (no. ICN 093585 ) data as for holotype . Specimen preserved in alcohol; deposited at same institution as holotype.

Diagnosis. The new species can be distinguish by: [1] epiproct quadrate in outline, compact; and [2] distal margin of epiproct pointed, triangular.

Description. Male (holotype). Body length 7.0 mm; interocular distance 1.0 mm; pronotum length 1.5 mm, pronotum width 1.9 mm; tegmina length 1.0 mm; metatarsus 1.0 mm. ( Figs. 1–4 ).

Head brown. Lateral carinae extended from the occiput towards but not reaching the compound eyes. Medial carinae on the top of the head extended along half-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 bearing strong setae. Labial palp with three segments; last segment bearing 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. Mesonotum (episternum) with a patch of setae. Tegmina short with subcostal vein thick. Alae absent. Prothoracic leg brown. Procoxa elongate, subquadrate, with few hairs along the inner margin. Protrochanter short. Inner margin of profemur with rows of hairs along the edges, external edge with longer setae. Protibia distally wider than basally, with three strong spines, and densely covered with two types of setae: one long and hair-like, and the other strong and spine-like. Protarsus with two tarsal segments; last segment with a pair of claws. Metathoracic leg brown, darker brown coxa, trochanter and femur, and lighter brown tibiae and tarsal segments. Metathoracic leg brown, trochanter absent; metafemur large, brown with a white vertical mark anterior to the semilunar process; inner carinae, ventral and dorsal edge of femur dark blackish-brown. Metatibia without lamellae, with two dorsal rows of 15 spines outer and 15 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 group of setae. A pair of apical spurs with an inner apical group of setae are present; the spurs are twice as long as the inner subapical spurs. Metatarsus strong and as long as cerci, a terminal tooth and an outer subapical tooth are present followed by a row of minute teeth along the edge; inner dorsal edge with a row of densely clustered setae; ventral edge with one row of setae. Tip of spurs is reddish, tooth-like and the same reddish coloration is observed on the tibial rows of spines.

Abdomen brown. 10-segmented, segment 9 corresponding to the subgenital plate with rounded margin; segment 10 is merged with the terminalia. 10th tergum with medial membranous triangular groove, margin straight not extended and 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 compact, quadrate. Proximal margin almost straight, without invagination; distal margin of epiproct pointed, triangular with setae. Phallus membranous with spikes ( Fig. 5 ).

Female. Body length 9.5 mm; interocular distance 1.1 mm; pronotum length 1.4 mm, pronotum width 2.0 mm; tegmina length 0.9 mm; metatarsus 1.1 mm (n=1).

Body similar to male, except for antennae brown. Scape wider than pedicel, similar length. Flagellomere 1 longer than pedicel. Flagellomere 2 shorter than flagellomere 1. Protibia distally extended with four strong spines, densely covered with thicker setae than male; two types of setae, one long and hair-like, the other strong and spinelike. Metatibia with two dorsal rows of 11 outer spines and 12–13 inner spines.

Abdomen brown. 10-segmented, segment 8 corresponding to the subgenital plate with rounded margin. 10th tergum with a medial membranous groove drop-shaped, margin slightly rounded; two pairs of setae are present near the posterior margin, each one in a corner of the membranous groove. Epiproct tongue-like with setae in distal margin.

Etymology. The specific epithet is from the Latin “ quadratus ” meaning “square” in reference to the shape of the compact, quadrate epiproct of the male.

Distribution. Known only from the type locality.

Remarks. The new species generally resembles the other species in the genus. From the Australian species it is easily differentiated by the size ( Table 1). Australian species are smaller, with males less than 5 mm ( D. quadratus is 7 mm long). Moreover, the apex of the tegmen in D. quadratus is blunt (a character shared with the other new species from Colombia) whereas in the Australian species, the tegminal apex tends to be elongate and curved (especially elongated in D. keyi ). The new species lacks white margins on the pronotum such as in D. albisignatus (pronotum with white marks on laterocaudal edges) and lacks a tooth or extended margin of tergite 10 such as in D. keyi (margin of tergite 10 with two tooth-like extensions). The female can be distinguished from D. raggei in the shape of the subgenital plate that does not protrude apically. From D. denticulatus (the Brazilian species) it is distinguished by the shape of the epiproct, the lateral margin of which is without indentation in D. quadratus .

Figures

FIGURES 1–4 Dentridactylus quadratus, sp. nov. holotype male. 1 Habitus in dorsal view. 2 Habitus in ventral view. 3 Subgenital plate in ventral view. 4 Terminalia in dorsal view.

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