Taciturna baiderae Hugel

Hugel, Sylvain, 2014, Burrowing crickets endemic to summits in Mauritius (Orthoptera, Gryllidae): occupation of similar niches by species possibly derived from Australasian and African colonists, Zootaxa 3852 (3), pp. 382-390 : 383-385

Taciturna baiderae Hugel n. sp.

( Figs. 1–10 ; Tab. 1 )

Holotype. Male. Mascarene archipelago, Mauritius, [Port Louis District], Le Pouce; 492 m alt., 20.2023°S 57.5260°E; 27.II.2008; S. Hugel leg. (BIOTAS 2008 276), MNHN (MNHN-EO-ENSIF3729).

Paratypes. Males. 1♂ same as holotype, ab larva, SH coll. 2♂ 6.XI.2013, Corps de Garde (Mau 2013 137 and 147), 700 m alt., 20.2613°S 57.4535°E, all SH coll. Females. 1♀, as holotype, (Biotas 2008 418), MNHN (MNHN- EO-ENSIF3730). 1♀, 8.V.2009, Le Pouce, dernier plateau, 725 m alt., 20.1990°S 57.5290°E; S. Hugel leg. (BIOTAS 2009 389), SH coll. 1♀, 10.XI.2014, chemin du Piton de la Rivière Noire, 650 m alt., 20.4186°S 57.4151°E; S. Hugel leg. (Mau 2013 219), SH coll. 1♀, 18.I.2013, Deux Mamelles; B. Warren leg. (POI418), SH coll.

Diagnosis. Taciturna baiderae n. sp. is distinguished from the two other Taciturna by combination of the following: size smaller ( Table 1 ); hind tibia short, 0.44–0.55 times as long as hind femora; male forewing short, 2/ 3 as long as pronotum ( Fig. 1 ); male epiphallic sclerite moderately narrowing posteriorly, with moderately diverging lophi (dorsal view, Fig. 5 ), lophi weakly upcurved ( Fig. 6 ).

Description. Male. Head and antennae: eyes of normal size for the genus, not protruding, separated by>2 times their diameter (dorsal view; Fig. 1 ); rostrum>2 times wider than scapus (dorsal view; Fig. 1 ); maxillary palpi 4th article as long as the 3rd article, apex of 5th article moderately enlarged. Thorax. Pronotum slightly wider than long ( Fig. 1 ); weakly trapezoidal: wider anteriorly than posteriorly; with a longitudinal depression; anterior margin distinctly concave, posterior margin straight; lateral margins weakly convex. Legs. Tympana lacking on both sides of fore tibia. Fore tibia with 2 anterior and 1 posterior ventral spur. Mid tibia with 1 ventral inner spur; 1 ventral outer spur, 1 dorsal inner spur, 1 dorsal outer spur. Fore and mid basitarsus with two rows of ventral spinules. Hind femora 3 times longer than wide. Hind tibia 0.5 times as long as hind femora. Hind tibia with 3 inner and 3 outer apical spurs ( Fig. 3–4 ); with 3 outer subapical spurs, with 3–4 inner subapical spurs ( Fig. 3–4 ); with 2–4 outer spines proximal to the subapical spurs. Hind basitarsus strongly enlarged distally (side view), with 5–7 outer and 5–6 inner dorsal spines ( Fig. 3–4 ). Genitalia. Epiphallic sclerite symmetrical, with broadly separated lophi projecting posteriorly ( Fig. 5 ). Lophi weakly diverging distally (dorsal view, Fig. 5 ); moderately upcurved (side view, Fig. 6 ). Pseudepiphallic parameres not visible dorsally, not reaching the distal end of epiphallic sclerite ( Fig. 7 ). Female. Similar to male but lacking wings. Terminalia. Ovipositor valves very short, not exceeding the subgenital plate ( Fig. 10 ). Copulatory papilla spoon-shaped ( Fig. 8–9 ). Color: body dark brown, with light brown in: upper part of rostrum, anterior angle of pronotum lateral lobes, abdomen. Fore and mid legs light brown except the knee area darkened. Hind femora with darkened knee area and stripes in the outer field. Hind tibia dark brown. Wings red-brown.

Variations. When compared to males from the type locality, males from Corps de Garde and Piton de la Rivière noire display slightly different epiphallus (size of lophi, pseudepiphallic parameres less overlapping), but these small differences are difficult to interpret with the few males available.

Biology. Tacirurna baiderae n. sp. spends most of its live underground. During night hours, adult males and females are seldom seen near the entrance of their burrows, the latter often transporting plant material within it.

The species can also be observed while removing very large rocks. In captivity, adult females lay ca. 20 large eggs in a 2 cm chamber at 15 cm from the ground surface. Females clean and turn the eggs during the 20 daysincubation and bring plant material to juveniles (at least the 1st instar). At 22°C, the full cycle lasts 4 months.

Etymology. Taciturna baiderae n. sp. is named after the Mascarene botanist Claudia Baider. The help of Claudia Baider and her partner Vincent Florens was invaluable in every step of my work on Orthoptera from Mauritius, and was particularly critical for the discovery of that new species.

Figures

FIGURES 1 – 4. Taciturna baiderae n. sp. 1, dorsal view of male; 2, frontal view of face; 3, right hind tibia, outer view; 4 right hind tibia, inner view. Scale bars: 1: 10 mm; 2 – 4: 1 mm.

FIGURES 5 – 10. Taciturna baiderae n. sp. 5 – 7, male holotype genitalia in dorsal view; 5, right side view; 6, ventral view; 7. 8 – 10 female genitalia; 8 – 9, copulatory papilla in left side view; 8, and dorsal view; 9. 10, female last abdominal tergites (cerci removed). Scale bars: 1 mm.

Tables

TABLE 1. Measurements (mm) of Taciturna baiderae n. sp.

Total	Head	Head	Pro	Pro	FW	F1	F2	F3	F3	T3	Bt
L	L	W	L	W	L	L	L	L	W	L	L
Male Holotype 14.9	2.0	2.7	2.9	2.9	1.9	3.3	3.2	8.5	2.8	4.4	2.7
average males (4) 14.7	2.1	3.1	2.9	3.1	1.8	3.2	3.3	8.6	2.9	4.4	2.8
min males 13.3	1.8	2.7	2.4	2.9	1.6	2.3	2.8	7.2	2.4	4.0	2.7
max males 16.0	2.3	3.4	3.4	3.4	1.9	4.0	3.8	10.4	3.5	4.6	2.9
average females (3) 14.3	2.3	3.4	2.7	3.0		3.3	3.3	9.0	3.0	4.1	2.4
min females 13.0	2.3	3.3	2.3	2.8		2.9	3.0	7.7	2.4
max females 16.0	2.3	3.4	3.4	3.1		4.0	3.8	10.4	3.5
L: length; W: width.