Spinapecta, Naskrecki, Piotr & Lopes-Andrade, Cristiano, 2005

Naskrecki, Piotr & Lopes-Andrade, Cristiano, 2005, A new genus and species of katydids of the tribe Polyancistrini (Orthoptera: Tettigoniidae: Pseudophyllinae) from Brazil, an apparent pest of Eucalyptus plantations, Zootaxa 952, pp. 1-8 : 3-4

Spinapecta gen. n.

Type species. Spinapecta alieniphaga sp. n.

Diagnosis. Body robust and stout; brachypterous; cuticle smooth. Pronotum large, shieldlike; lateral carinae with numerous short spines; metazona greatly expanded, elevated, and covering most of wings. Male left tegmen with single, thick stridulatory file; female left tegmen with veins Cu1 and Cu2 with stridulatory pegs on ventral surface. Meso­ and metasternum with 4 spines each. All legs slender; all femora armed on both lower margins, unarmed dorsally. Male cercus short, with single apical tooth; male tenth tergite thick, heavily sclerotized, emarginated apically; male subgenital plate with wide apical incision, styli short; ovipositor weakly curved, its apex minutely dentate.

Description. (male except where specified). Head. Fastigium of vertex small, triangular, slightly projecting in front of antennal sockets, with shallow dorsal groove; no traces of genal carinae present. Eyes circular, small relative to size of head, weakly protruding; ocelli absent. Frons weakly convex, smooth; surface of head smooth, without traces of genal carinae. Mandibles and labrum symmetrical. Antennae thin, slightly longer than body.

Thorax and wings. Pronotum large, shield like, elliptical when seen from above; lateral carinae with numerous short spines; spines continue around metazona, anterior dorsal margin of pronotum unarmed. Dorsal surface of pronotum smooth, with 2 shallow, transverse sulci; metazona raised, forming shallow shield above wings. Lateral lobes of pronotum nearly vertical, smooth. Thoracic auditory spiracle small, elliptical, completely exposed below lower margin of pronotal lobe. Prosternum armed with two thin, short spines (modified basisternum); meso­ and metasternum with lateral lobes of basisterna each equipped with pair of spines; meso­ and metasternum with pair of open, clearly visible meso­ (fu2o) and metafurcal (fu3o) orifices. Tegmina in both sexes reduced, nearly completely hidden under pronotum, slightly exceeding hind margin of 2nd abdominal tergite; hind wings reduced to small, fleshy lobes. Male stridulatory apparatus well developed; right tegmen with large, triangular mirror, surrounded by thick, elevated veins; left tegmen with slightly smaller mirror; stridulatory vein on left wing thick, elevated, with about 120 wide, lamelliform teeth; underside of Cu1 of male tegmina with large, bulbous tubercle. Female stridulatory organs present, structurally different from those of male; right wing without distinct mirror but with large, membranous area between median vein and posterior margin of tegmen, posterior margin of right tegmen thickened, forming distinct scraper; left tegmen with narrow stridulatory teeth on underside of veins Cu (~60 teeth) and AA1 (~100 teeth).

Legs. Legs slender; fore coxa with elongate, forward projecting spine dorsally. Femora unarmed dorsally; their surface uneven; all femora armed ventrally on both margins with short, immovable spines; genicular lobes with short spine each. All tibiae armed with short, immovable spines on both dorsal and both ventral margins; apex of fore and mid tibia with pair of short, movable spurs on ventral margin; apex of posterior tibia with 2 pairs of such spurs on ventral margin. Tympanum on fore tibia bilaterally closed, tympanal slits facing forward, tympanal area flat.

Abdomen. Dorsal surface of abdominal terga smooth, unmodified. Male tenth tergite strongly enlarged and sclerotized, with distinct apical incision; it overhangs and completely hides small, triangular epiproct (=supraanal plate). Cerci small, hook­like, with single apical tooth, in resting position hidden under tenth tergite. Subgenital plate large, strongly sclerotized, with wide apical incision, resulting in presence of 2 distinct lobes; each lobe of subgenital plate with small stylus. In resting position tenth tergite and subgenital plate form nearly uniform shield that hides internal, membranous phallus. Phallic structures without sclerotized elements. Female subgenital plate wide, approximately square, with pair of small lobes on posterior corners. Ovipositor narrow, weakly curved; about as long as hind femur; both dorsal and ventral margins of ovipositor smooth, parallel; apical part of lower valvula with minute teeth.

Etymology. The generic name Spinapecta is derived from Latin words spina = thorn and pectus = breast, to reflect the presence of strong spines on the sternum in the only species of the new genus.

Remarks. The genus Spinapecta is a monotypic taxon, erected for a species found in abundance in Grão Mogol, Minas Gerais State (Southeastern Brazil). It appears to be most closely related to the Caribbean genus Polyancistrus . These two genera share a similar form of the pronotum, with strongly enlarged, elliptical metazona, surrounded by spiny lateral carinae. The general habitus of the new genus also resembles Camposiella notabilis Hebard from Ecuador but the pronotum in C. notabilis has unarmed lateral carinae, and the basisterna of its thorax are equipped with only a single spine. Spinapecta differs from all members of the tribe Polyancistrini by the following apomorphies: (i) the meso­ and metasternum each equipped with 2 pairs of spines on lateral lobes of the basisterna; (ii) a unique development of the male tenth tergite, which forms a nearly sealed shield that appears to protect softer elements of the reproductive structures; (iii) a wide, strongly sclerotized and apically incised subgenital plate in the male; and (iv) the presence of unique stridulatory structures in the female, different from those present in other genera of the Polyancistrini . The last characteristic indicates that females of Spinapecta are capable of producing sound, but its nature is unknown. In Hispaniolan Polyancistrus serrulatus (Palisot de Beauvois) females produce loud disturbance calls when captured as well as advertisement calls if kept away from males of their species and prevented from mating. Their advertisement calls are remarkably similar to those produced by conspecific males, despite being produced by an apparatus different from that of a male. In Polyancistrus the female stridulatory file is located on the right tegmen and has teeth on the dorsal surface of the vein. The vein modified for stridulation appears to be either one of the anal or cubital veins, and runs in a sinusoidal fashion along the inner (posterior) margin of the tegmen. A similar but somewhat smaller vein is located on the left tegmen. The function of the scraper is played by the ventral portion of the inner margin of the left tegmen. There is no clearly defined, membranous mirror, but the central portion of the tegmen behind Cu2 is devoid of veinlets and may in fact function as a resonator. In Spinapecta the situation is reversed: the female stridulatory files are located on the ventral side of the left tegmen, and the function of the scraper is played by the posterior, thickened edge of the right tegmen.