Zephronia chrysomallos Bhansali & Wesener, new species

Figures 2A–B, 6B, 7, 8, 9, 10, 11.

Diagnosis. The position of the organ of Tömösváry at the brim and not in the antennal groove identifies this species as a member of the Zephronia sensu stricto group, with which it also aligns weakly genetically (Fig. 1). The sensory cones on the palpi of the gnathochilarium are arranged in a single field, not in separate clusters (Fig. 8D) and the body is covered in a dense coat of golden setae like in several other Thai Zephronia . The greyish brown tergites color resembles those of Z. erawani sp. nov. and Z. panhai (Fig. 2B). The male second leg mesal coxal margin is not extended into a membranous process, a character shared only with Z. lannaensis and Z. panhai . Zephronia chrysomallos sp. nov. differs from Z. lannaensis in the color (grey versus brown), telopod characters as well as the endotergum. Z. chrysomallos sp. nov. differs from Z. panhai in being much larger in size (40 mm versus 20 mm), the higher number of ventral spines on the walking legs (10–12 versus 7–9), the higher number of apical cones on the antenna (78–88 versus around 50), the higher number of rows of marginal bristles on the endotergum (3 versus 2) and the shape of the first pleurite, which is weakly extended and well-rounded in Z. chrysomallos sp. nov. but with a long sharp process in Z. panhai . Z. chrysomallos sp. nov. differs genetically in the COI barcoding fragment from Z. panhai by a p-distance of 10.8%, from Z. erawani sp. nov. by a p-distance of 11.9% and from Z. lannaensis by 14.8–15.2% (Sup. file 1).

Derivatio nominis. chrysomallos, Greek, meaning Golden Wool, and also the flying sheep ram Chrysomallos from Greek mythology, which was sacrificed to Zeus in order to obtain the famous Golden Fleece. Noun in apposition.

Material examined (total: 7 ♂♂)

Holotype

THAILAND: 1 ♂, ZFMK MYR8826, Kanchanaburi Province, Sai Yok District, Sai Yok Noi Waterfall, 14°14'12'' N, 99°03'46'' E, 150 m.

Paratypes

THAILAND: 1 ♂, ZFMK MYR11366, CT scan voucher, same data as for holotype; 1 ♂, ZFMK MYR11365, same data as for holotype .

Other material

THAILAND: 4 ♂♂, CUMZ, Kanchanaburi Province, Sai Yok District, Sai Yok Noi Waterfall (Khao Phang WF), 14°14'21'' N, 99°03'28'' E, ca. 160 m a.s.l., 11.VII.2009, leg. ASRU members .

Description (based on holotype)

Size. Length: ca. 40 mm. Width of thoracic shield 16.3 mm, of widest segment (8th) 16.9 mm. Height of thoracic shield 9.4 mm, of highest segment (8th) 11.5 mm.

Color (from living specimens). Head, collum and anterior margin of thoracic shield dark brown to black. Antenna dark brown, legs pale brown. Tergites and anal shield greyish-brown (fading to light brown in ethanol), darker towards posterior margin. Thoracic shield-like tergite with darker anterior and posterior margins. (Fig. 2B).

Head (Fig. 7D). Number of ommatidia more than 90. Tömösváry organ placed on rim of antennal groove. Antennae (Fig. 7A–D) short, axe-shaped (Fig. 8A–C), not reaching to center of head (Fig. 7C), antennomere lengths: 6>1>5=4=3=2. Antennomere 1 basally with scales (Fig. 8A). Antennomere 6 apically wide, and flattened, axe-shaped, with 78/88 apical cones (Fig. 8C).

Epipharynx. With a large inner tooth.

Gnathochilarium (Figs 7D, 8D–F, 9A). Lamellae linguales with numerous long setae, more towards the margins. Stipes and mentum with numerous long setae in a regular pattern (Fig. 9A). Gnathochilarium palpi with sensory cones arranged in single field (Fig. 8E). 'Pillows' of central pads with two types of sensory cones (Fig. 8F).

Mandible (Fig. 9B). External tooth undivided, inner tooth with 3 lobes. Pectinate lamellae with 6 or 7 rows. Condylus at anterior margin with two distinct ridges.

Collum (Figs 7A, C). With few setae distributed towards the margins, more concentrated towards lateral ends.

Thoracic shield. Thoracic shield grooves wide and shallow (Figs 7A–C), without sclerotized ledges.

First stigmatic plate (Fig. 10A). Smaller than coxa, with rounded sub-triangular apex.

Tergites. Tergites densely covered in short, dense setae visible at higher magnification, with dull orange skinlike surface (Fig. 2B). Paratergite tips only weakly projecting backwards (Fig. 7B).

Pleurites. Pleurite 1 well-rounded, weakly projecting. Pleurite 2 well-rounded, not projecting (Fig. 7C).

Endotergum (Fig. 6B). With a regular flat margin. Outer area with two dense rows of marginal setae, reaching 4/5 of outer area. Middle section with a single row of rounded cuticular impression, distance between impression 2–3 times their diameter. Inner area without setae or spines.

Legs. Ventral spines on leg 1 2/2, at 2 4 /4, at 3 5/5. Leg 3 with single apical spine. Mid-body legs with 3 or 4 apical and 10–12 ventral spines (Fig. 10B). Inner margin of femur with 12–15 small triangular teeth, concentrated at apical half, but not excavated. Femur 1.5, tarsus 3.3 times longer than wide.

Anal shield. Well-rounded and like tergites covered with short dense setae visible at higher magnification (Fig. 2B). Ventral side with dark-colored medium-sized locking carina placed slightly closer to pleurite than margin (Fig. 7C).

Male sexual characters. Male gonopore consisting of large membranous opening located directly at mesal margin of coxa 2 (Fig. 10C). Coxae 2 without membranous processes.

Anterior telopods (Figs 10D–F). Syncoxite setaceous. Podomere 1 rectangular, as long as wide. Few setae, mainly at margins and in apical half. Podomere 2 in anterior view as wide as but slightly narrower as podomere 1. Process massive, visible in anterior view (Fig. 10E), relatively short and wide. Process protruding above basal half of podomere 3, triangular (Figs 10E, F). Podomere 3 cylindrical, 1.4 longer than wide, with one spine in the mesal membranous region, apically with 4 crenulated teeth (Fig. 10D). Podomere 4 clearly separated from podomere 3, conical bearing a black spot at apex. Meso-posterior margin with two spines.

Posterior telopods (Fig. 11). Syncoxite inner horns (not drawn): apex well rounded, apically diverging. Podomere 1 rectangular, as wide as long, with short setae. Podomere 2 with long and narrow immovable finger, 5 times longer than wide. Immovable finger slightly wider posteriorly and apically very slightly curved towards movable finger. Immovable finger glabrous, remaining part of podomere 2 setose. Membranous lobe bearing 2 elongated processes, fused at base. Podomere 3 in posterior view glabrous, in anterior view basal half setose. With a row of 17 or 18 large crenulated square teeth on posterior side (Fig. 11B). Membranous ledge on podomere 3 with single spine. Podomere 4 on both sides glabrous, slightly curved towards immovable finger, membranous lobe with 2 spines. Immovable finger shorter than movable finger.

Distribution

Z. chrysomallos sp. nov. is currently only known from the type locality near the Sai Yok Noi Waterfall (Fig. 2A) and might be microendemic, as are other, closely related species in nearby forests.