Amyttacta farrelli, Naskrecki & Bazelet & Spearman, 2008

Naskrecki, Piotr, Bazelet, Corinna S. & Spearman, Lauren A., 2008, New species of flightless katydids from South Africa (Orthoptera: Tettigoniidae: Meconematinae), Zootaxa 1933 (1), pp. 19-32 : 21-22

Amyttacta farrelli n. sp.

( Figs. 1A–I , 3C–D , 4A–B )

Type locality. REPUBLIC OF SOUTH AFRICA: Limpopo, Lebowa, Bolobedu Dist., nr. Duiwelskloof , (23°37'37.5''S, 30°22'11.9''E), 855 m, 28.ii.–2.iii.2008, coll. B. Gcumisa, C. Bazelet & P. Naskrecki —male holotype ( PPRI)

Differential diagnosis. A. forrelli can be distinguished from A. rhodesica and A. angolensis by the strong reduction of wings (the last two are fully winged.) From A. marakelensis it differs in the larger body size as well as the shape and armature of the male cercus.

Description (male, except where specified)

General. Body small, slender, cylindrical ( Figs. 3C, D ); male brachypterous, female squamipterous.

Head. Antennal scapus unarmed. Fastigium of vertex parallel-sided, blunt apically, as wide as 1/2 of antennal scapus, not reaching apex of antennal sockets, flat dorsally; antennae about twice as long as body; frons flat, vertical; eyes circular, weakly protruding.

Thorax. Humeral sinus of pronotum absent, lateral lobe almost 3 times as long as high; anterior margin of pronotum straight, flat; metazona flat ( Fig. 1A ), posterior edge of metazona narrowly rounded. Prosternum unarmed.

Legs. Legs slender. Front coxa armed with long spine, front femur unarmed ventrally; genicular lobes of front femur unarmed. Front tibia unarmed dorsally, with 3 spines on posterior and 3 on anterior ventral margin; tympanum bilaterally open, oval. Mid femur unarmed ventrally. Mid tibia not noticeably thickened in basal part, unarmed dorsally, with 3 spines on posterior and 4 on anterior ventral margin. Hind femur unarmed ventrally, genicular lobes of hind femur unarmed; dorsal spines of hind tibia with alternating size, smaller and larger.

Wings. Tegmen reduced, shorter than pronotum, completely hidden under metazona of pronotum; anterior margin nearly straight; hind wing absent. Costal field not dilated at base; veins Sc and R diverging towards apex of tegmen; right stridulatory area with large, fully developed mirror ( Fig. 1F ). Stridulatory file elevated on thickened vein, sharply bent in middle, with 33 teeth, 0.55 mm long, 0.03 mm wide ( Fig. 1G ). Female tegmen squamiform, shorter than half of pronotum.

Abdomen. Tenth tergite with posterior edge sclerotized, slightly raised, and with small, triangular incision; epiproct unmodified. Cercus long and slender, bent inwards ( Fig. 1C ); distinctly bent downwards when seen from side; unarmed, but with small, hook-like projection at base ( Fig. 1E ); apex narrowed, blunt; paraprocts strongly enlarged and forming large, blunt projection pointing down and overhanging subgenital plate ( Fig. 1D ); sclerotized epiphallus absent; subgenital plate unmodified, broadly trapezoidal, straight apically; styli cylindrical, about twice as long as wide, parallel ( Fig. 1B ). Female subgenital plate broadly trapezoidal, with wide, shallow apical incision ( Fig. 1I ).

Ovipositor. Ovipositor normally developed; almost straight, about as long as hind femur; apex pointed, with both valvulae smooth, dorsal edge of upper valvula parallel to lower valvula ( Fig. 1H ).

Coloration. Coloration light green, antennae concolorous; eyes uniformly colored; face without darker markings; occiput with two light yellow bands, continuous with bands on pronotum. Pronotum with light yellow band on upper side of lateral lobe; hind femur uniformly colored; abdominal sterna without markings; subgenital plate without markings.

Measurements (6 males, 6 females). — body: male 13.5–14.5 (14.1±.4), female 19–21 (20.4±.8); pronotum: male 5–5.5 (5.3±.2), female 5; tegmen: male 2.5, female 1; hind femur: male 9.5–10.5 (10±.3), female 10–11 (10.4±.4); ovipositor: 9.5–10.5 (9.9±.4) mm.

Material examined. — Republic of South Africa: Limpopo, Lebowa, Bolobedu Dist., nr. Duiwelskloof , elev. 855 m (23°37'37.5''S, 30°22'11.9''E), 28.ii.–2.iii. 2008, coll. B. Gcumisa, C. Bazelet & P. Naskrecki — 25 females, 21 males (incl. holotype, 45 paratypes) ( ANSP, MCZ, PPRI, SAMC, USEC) ; Blyde River Canyon, elev. 1341 m (24°34'20.5''S, 30°47'55.5''E), 2.iii. 2008, coll. B. Gcumisa — 1 female ( USEC) .

Etymology. Named in honor of Dr. Brian D. Farrell, a prominent coleopterist and evolutionary biologist.

Bioacoustics. Males of A. farrelli were recorded stridulating from low vegetation, often as low as 10 cm above the ground, between the hours 20:00 and 1:00. Stridulation produced by the males was entirely in the ultrasonic range, and could not be heard by human listeners. Using an ultrasound detector Pettersson D 200 we were able to measure the frequency range of the calls, which started around 31 kHz, and continued to at least 100 kHz. The energy peak, based on the intensity of the signal across the spectrum, appeared to be around 60 kHz. The call of A. farrelli consists of long echemes (4–25 seconds long), each made up of regularly spaced syllables (approx. 30 syllables/sec at 20°C), and each syllable lasted approximately 0.015 sec ( Figs. 4A, B ).

Figures

FIGURE 1. Amyttacta farrelli. A. male head and pronotum, lateral view; B. male subgenital plate; C. apex of male abdomen, dorsal view; D. ditto, lateral view; E. male right cercus, dorsal view; F. male left tegmen; G. stridulatory file; H. ovipositor; I. female subgenital plate; A. marakelensis. J. male right cercus, dorsal view; K. apex of male abdomen, dorsal view; L. ditto, lateral view; M. male left tegmen; N. stridulatory file; O. spines on hind tibia.

FIGURE 3. Paracilacris mordax. A. titillator, dorsal view; P. periclitatus. B. titillator, dorsal view; Amyttacta farrelli. C. male, lateral view; D. female devouring the spermatophylax; Paracilacris periclitatus. E. male, dorso-lateral view (green form); F. female, dorso-lateral view (brown form).

FIGURE 4. Oscillograms of male airborne calls. Amyttacta farrelli. A. 5 s fragment of an echeme; B. 0.5 s fragment showing syllables; Paracilacris periclitatus. C. 5 s fragment of echeme-sequence; D. 0.5 s fragment showing a single echeme.