Bioacoustics of Conocephalus (Anisoptera) maculatus

Description. Male — Fastigium of vertex moderately wide, anterior margin of pronotum concave, posterior margin rounded. Prosternum bispinose, macropterous, forewing pigmented with comparatively large dark spots; no marking in costal and percostal area, cross veins of costal and perocostal area of forewings irregular to almost regular. Stridulatory file area of male left tegmen large, stridulatory file elevated on thickened vein, slightly rounded, about 52 large and 28 small teeth with main teeth very robust, which are large and spaced in the middle, gradually becoming narrower towards the apex. Hind femora unarmed ventrally. Tibia marked with spot towards base, dark on mid tibia, often faint on other. Hind tibiae with 6 apical spurs. Tenth tergite slightly broad, basal margin arched, concave, posterior margin with a pair of obtuse lobes. Cerci conical with spines in middle and at the apex small spine-like projection. Subgenital plate long with middle carinae, posterior margin incision in the middle; styli long, cylindrical, apices obtuse. Female: Tenth abdominal tergite small, incision in middle with apical margins rounded. Epiproct small, triangular, rounded with apex obtuse. Cerci conical at base, suddenly narrowing, apex obtuse, hirsute. Subgenital plate slightly broader anteriorly and posterior narrowing posteriorly, flat, apical lobe slightly rounded. Ovipositor moderately straight and slightly curved upward, dorsal and ventral margins smooth, dorsal valve longer than ventral.

Distribution and natural history. One of the most widely distributed species of Conocephalus , recorded from most of SE Asia, Pacific islands, New Guinea , and Australia ( Pitkin 1980 ), Yemen , Saudi Arabia ( Ingrisch 1999 ), Madagascar ( Redtenbacher 1891 ) West and Central Africa (Chopard 1954; Ragge 1967 ), Tanzania ( Hemp 2013a ), Zimbabwe , and South Africa (pers. obs. and specimens at ANSP, TMSA, USEC). In Mozambique this species was first recorded by Chopard (1935) from Chimoio (“Vila Pery) and Vunduzi in Sofala Province . One of the most common katydids in Gorongosa , its adults are present throughout the year in grassland and open woodland habitats, from the lowland floodplain of Lake Urema to the lower slopes of Mt. Gorongosa (up to ~ 1,000 m a.s.l.) This species feeds on grasses and small, soft-bodied insects. Bioacoustics. Males call both during the day and early at night; the call is a continuous, wide-spectrum buzz, with most of the acoustic energy within 20–50 kHz but without a distinct frequency peak; lower frequency portion of the call is easily audible to the human ear ( Figs. 45 A–C). Measurements ( 3 males , 3 females ). body w/wings: male 26–26.5 (26.2.3), female 24–26 (25.31.2); tegmen: male 18–20 (18.81), female 20–22 (21.31.2); hind femur: male 14–15 (14.7.6), female 15–16 (15.7.6); ovipositor: 8–9 (8.7.6) mm.

Plate 1 , Figs A–B; Plate 2 , Figs 1 –17 Redescription Male: Small size and slender body. Head: fastigium compressed laterally; base of fastigium wider than scapus and apex rounded; eyes globular and bulging outward; Thorax : Pronotum with disc slightly raised; anterior margin weakly concave, posterior margin rounded; median carina indistinct; lateral lobes triangular, deeper than long with secondary tympanum present on posterior edge; humeral sinus indistinct; prosternum with a pair of spines; mesosternal lobes elongated and triangular; metasternal lobes rounded; thoracic auditory spiracle large, partially hidden under the lateral lobe of pronotum. Tegmina shorter than hind wings, apex rounded; hind wings not surpassing the middle of hind tibia; stridulatory file with 50 teeth on the ventral side of left tegmen, teeth of file with rough surface, evenly spaced, gradually decreasing in size towards the distal end, file gradually narrow and sulcate towards distal end; Legs : Genicular lobes of fore femora armed with a single spine on inner side and unarmed on outer side; mid and hind genicular lobes with a single spine on both inner and outer sides; fore coxae with a single spine; all femora dorsally and ventrally spineless; tympanum present on fore tibia, the opening is directed towards dorsal side with a pair of small pits laterally just below the tympanum; fore and mid tibiae dorsally unarmed; fore tibiae ventrally armed with 6 spines on inner margin; 6 spines on outer margin; mid tibiae ventrally armed with 6 spines on inner margin; 6 spines on outer margin; hind tibiae dorsally with variable number of small spines both inner and outer spines; ventrally hind tibiae with 7 spines on inner margin; 11 small to moderate sized spines arranged on outer margin; single dorsal pair of spurs and two ventral pairs (outer large and inner being small) of spurs present on apical region of hind tibiae. Abdomen: tenth tergite relatively broad with distinct median carina, basal margin concave, apical margin with a pair of obtuse lobes; supra-anal plate triangular, apex sub-obtuse; subgenital plate long with indistinct median carina, apical margin with rounded excision; styles long, cylindrical; cerci thick basally, tapering towards apex; tooth at middle, thick at base, apex with a spine like projection. Female: Last abdominal tergite with median incision, apical margin rounded; supra-anal plate triangular, with basal groove, apex sub obtuse; subgenital plate as long as broad, apical margin with weak rounded excision; cerci conical, slightly thick, weakly up curved; ovipositor regularly upcurved, slightly surpassing the wings; ovipositor shorter than hind femur.

Redescription. Male: Body small sized and slender. Fastigium of vertex compressed laterally; base of fastigium 1.68 times as wide as scapus. Fastigium verticis moderately wide, apex rounded. Eyes globular and protruding outward. Pronotum: pronotal disc slightly raised; anterior dorsal margin weakly concave, posterior margin rounded; median carina hardly visible; lateral lobes triangular, higher than long with secondary tympanum present on posterior edge; humeral sinus weak. Prosternum armed with a pair of spines; mesosternal lobes elongated and triangular; metasternal lobes rounded. Thoracic auditory spiracle large, elliptical, partially hidden under lateral lobe of pronotum; a weak tubercle is present at mid anterior inner edge of spiracle. Tegmina shorter than hind wings, apex rounded. Hind wings reaching before the middle of hind tibia. Stridulatory file with 50 teeth on the ventral side of left tegmen, teeth of file with rough surface, evenly spaced, gradually decreasing in size towards the distal end, file gradually narrow and sulcate towards distal end. Legs: All tibiae have a basal dark spot. Genicular lobes of fore femora armed by a single spine on inner side and unarmed on outer side; mid and hind genicular lobes armed by single spine on both inner and outer side. Fore coxae armed by a single spine. All femora dorsally and ventrally unarmed. A slit like tympanum present on fore tibia, the opening is directed towards dorsal side with a pair of small pits laterally just below the tympanum. Fore and mid tibiae dorsally unarmed. Fore tibiae ventrally armed by 6 spines on inner margin; 6 spines on outer margin. Mid tibiae ventrally armed by 6 spines on inner margin; 6 spines on outer margin. Hind tibiae dorsally armed by 38 minute to small sized, thick spines on inner margin; 32 minute to small sized, thick spines on outer margin. Hind tibiae ventrally armed by 7 small to moderate sized spines arranged on inner margin; 11 small to moderate sized spines arranged on outer margin. Single dorsal pair of spurs and two ventral pairs (inner small and outer large) of spurs present on apical region of hind tibiae. Tenth abdominal tergite slightly broad with distinct median carina, basal margin concave, apical margin with a pair of obtuse lobes. Supraanal plate triangular, apex sub-obtuse. Subgenital plate long with hardly visible median carina, apical margin with rounded excision; styles long, cylindrical and diverging apically. Cerci thick basally, compressed apically on lateral inner side, lateral outer side slightly concave; median internal tooth thick at base, apex with a spine like projection. Female: Tenth abdominal tergite with median incision, apical margin rounded. Supra-anal plate triangular, with basal groove, apex sub obtuse. Subgenital plate as long as broad, apical margin with weak rounded excision. Cerci conical, slightly thick, weakly upcurved. Ovipositor slightly upcurved, dorsal valve longer than ventral; slightly surpassing the wings; length of ovipositor moderately shorter than hind femur. Morphometry (length in mm)