Arachnoscelis arachnoides

Montealegre-Z, Fernando, Cadena-Castañeda, Oscar J. & Chivers, Benedict, 2013, The spider-like katydid Arachnoscelis (Orthoptera: Tettigoniidae: Listroscelidinae): anatomical study of the genus, Zootaxa 3666 (4), pp. 591-600 : 595-599

Arachnoscelis arachnoides

Redtenbacher. 1891. Verh. der Zoologisch-Botanischen Gesellsch. Wien 41: 230, 232 >> Listroscelis arachnoides

Giglio-Tos. 1898. Boll. Musei Zool. Anat. Comp. R. Univ. Torino 13 (311): 93 >> Listroscelis arachnoides

Saussure & Pictet. 1898. Biologia Centrali-Americana 1: 403 >> Listroscelis arachnoides

Kirby, W.F. 1906. A Synonymic Catalogue of Orthoptera (Orthoptera Saltatoria, Locustidae vel Acridiidae) 2: 288 >> Listroscelis arachnoides

Otte, D. 1997. Orthoptera Species File 7: 80 >> Arachnoscelis arachnoides

Chamorro-Rengifo, Cadena-Castañeda, Braun, Montealegre-Z., Romero, Serna Marquez & Gonzales. 2011. Zootaxa 3023:14 >> Arachnoscelis arachnoides

Redescription. Head.— Mandible body enlarged, curved latero-ventrally in males but reduced with normal appearance in females. Both male and female with a well developed tooth between the molar and incisor ( Fig. 2 ). Wings.— Both mirrors ovoid ( Fig. 4 AE), right mirror area of 0.51 mm 2, left mirror smaller, 0.42 mm 2. Stridulatory file bearing 62–64 teeth. Measured from the anal side of the file, inter-tooth spacing rapidly and consistently increases in the first third of file length from ca. 14µm to 40µm, decreases during the second third from ca. 40µm to 10 µm, and slowly decreases from 10µm to 5 µm in the last third ( Fig. 4 C). Abdomen.— Male tenth tergite unspecialized, showing only two diffident lobes separated by a broad shallow notch ( Figs. 5 C, and 6A). Titilators delicately elongated, highly sclerotized and acuminate, projected upwards and protruding from the terminalia contour ( Fig. 5 C). Male cerci elongated and incurved, with distal tooth projected inward ( Figs. 5 B and 6A). Male subgenital plate basally expanded, bearing a broad v-shape notch and two distinct styli; the plate extends to the mid distance of the cerci ( Fig. 5 B). Female subgenital plate elongated and distally upcurved, bearing two distinct diverging lobes separated by a V-shaped notch ( Fig. 5 B).

Coloration. Sexual dimorphism is also observed in the coloration pattern ( Fig. 1 AB).

Male coloration. Scapus and first flagellar segment, and femora smaragdine (the brilliant crystalline green of the emerald) ( Fig. 1 A). Tibiae fulvous. Rostrum, clypeus and labrum fuscotestaceous, no facial marks present. Pronotum and abdomen brunneus. Tegmina albus-argentum (pearly). Abdominal tergum with two pale subtriangular spots which cover the first and second tergites; half a spot lays on the first tergite and the other half on the second tergite; the half on the first tergite is amber, while that on the second tergite become olivaceous or smaragdine.

Female coloration. Female body highly mottled ( Fig. 1 B). Occiput amber with two short brunneus strips between the eyes and two additional brunneus lines on each side, which continue anteriorad and delineate the eye sockets. Pronotal disk amber, pronotal lobes irregularly covered with a brunneus-atrous macula. Limbs resinousamber with irregular suffusions of brunneus dots and spots. All femora with two distinct bracelets of the same brunneus tone on distal half. Abdominal pleura atrous and abdominal terga ambar. Subgenital plate and cerci ambar, ovipositor fulvous.

Material examined. Neotype: 13, Colombia, Boyacá, Coper, Vereda Turtur, Sector San Ignacio, elevation 1561 m. April 20, 2008, (O. Cadena-Castaneda). Allotype: 1 Ƥ, Colombia, Boyacá, Coper, Vereda Turtur, Sector San Ignacio, elevation 1561 m. April 20, 2008 (O. Cadena-Castaneda). Paratypes: 53, Colombia, Boyacá, Coper, Vereda Turtur, Sector San Ignacio, elevation 1561 m. Oct. 25–29, 2009 (O. Cadena-Castaneda & F. Montealegre- Z); 23 January 15, 2013 (O. Cadena-Castaneda).

Depositories. COLOMBIA: Museo Universidad Distrital Francisco José de Caldas, Bogotá DC (MUD), Museo de Entomología Universidad del Valle, Cali (MEUV), Museo de Entomología Instituto de Ciencias Naturales, Bogotá DC (ICN).

* Original specimen described by Redtenbacher (1891).

Figures

FIGURE 1. Arachnoscelis arachnoides habitus; A. Male; B. Female.

FIGURE 2. Distinguishing structures of the head of Arachnoscelis arachnoides: A. rostrum of a male and a female; B. Male right mandible seen from internal and dorsal view; C. Isolated right mandible of the female in dorsal view. B and C illustrate mandible sexual dimorphism in the head structure; note the conspicuous enlargement of the mandible body in males.

FIGURE 4. The stridulatory file of Arachnoscelis arachnoides: A. The entire left tegmen in ventral view showing the stridulatory file and mirror; B. A close up view of the file. C. Average inter-tooth spacing measured from two males. Error bars indicate one standard error; D. Male tegmina in resting position; E. Right tegmen illustrating venation pattern. Venation nomenclature follows Bethoux (2012).

FIGURE 5. Distinguishing structures between males and females: A. Proximal part of the left tibia showing tympanal slits; B. Subgenital plates of males and females in ventral view. The male diagram also depicts cerci and styli; C. Lateral view of the male terminalia showing cerci, subgenital plate and titillators.