Bioacoustics of Plangia amaniensis

Description. Male. General habitus and colouration . Large Plangia species with elongated but broad tegmina and uniformly green colour ( Fig. 5 ). Head and antennae . Eyes prominent, globose, slightly oval. Antennae filiform, of whitish to tawny colour, shorter than flexed tegmina. Face green. Fastigium verticis very faintly sulcate, slightly narrower than scapus. Fastigium of vertex and fastigium of face meeting in deep sulcus, fastigium of vertex broader than conus-shaped fastigium of face. Thorax . Pronotal disc flat. Lateral pronotal lobes deeper than wide, ventral margin evenly rounded, anterior margin almost straight. Fore coxa with spine. All femora laterally compressed, dorsally unarmed. Fore femora with 5 brown-tipped spines posteriorly. Mid femora unarmed. Hind femora with 8 posterior spines. Fore tibiae slightly inflated in area of conchate tympanum; ventrally with double row of 4 spines and apical pair of spurs. On dorsal apical side one spur on outer side, on inner side rounded lobe. Mid tibiae ventrally with double row of 8 spines getting denser distally; inner 2–3 sets of spines more irregular positioned. Spurs as in fore tibiae. Hind tibiae with four rows of brown-tipped spines getting denser distally. Dorsal one pair of spurs, ventrally 2 double pairs of spurs. Wings. Sc and R contiguous, except near base, separating fork-like about mid of tegmen. Tegmina elongate with oval tip. Hind wings hyaline, longer than tegmina, visible part when folded of same colour as tegmina. Stridulatory file thick, on the lower side of left tegmen with approximately 80–85 teeth (N=1) ( Fig. 7 ). Abdomen . Plump, dorsal with yellow tinge. Tenth tergite unmodified with straight posterior margin. Cerci very long and slender, decussate ( Fig. 6 A, B ). Subgenital plate trough-shaped with u-like incised posterior margin and two tiny styli ( Fig. 6 B ). Female. Unknown. Measurements. males (N = 2) Total length of body 25–26 mm Median length of pronotum 6.6–6.7 mm Length of hind femur 22.5–23 mm Length of tegmina (lateral) 42–44 mm Diagnosis. A large and uniform green Plangia species and thus distinguished from most other Plangia species that are smaller in body size ( P. graminea ) or are characterized by a colour pattern of green or yellowish with dark patches or infumation on tegmina and body ( P. guttatipennis Karsch, 1889 , P. karschi Chopard, 1954 , P. multimaculata Hemp, 2015 , P. nebulosa Karsch, 1890 , P. segonoides (Butler, 1878) , and P. unimaculata Chopard, 1955 ). Only P. albolineata from Madagascar known from the female sex only is larger in body size than other Plangia species and has long and narrow tegmina and could thus be the female to P. amaniensis n. sp. However, it has a fastigium verticis unique for Plangia as stated by Brunner v. Wattenwyl 1878 and P. amaniensis n. sp. very likely is restricted to the East Usambara Mountains and here to submontane forests. P. villiersi Chopard, 1954 from West Africa known from the female sex only, has much broader tegmina. Males of P. amaniensis n. sp. are distinguished from all other Plangia species where the male is known by the long, decussate cerci. Plangia graminea , P. ovalifolia Bolivar, 1912 , P. satiscaerulea Hemp, 2015 , and P. variacantans n. sp. have short and stout cerci.