Bioacoustics of Lanista annulicornis

Distribution and natural history. L. annulicornis is known only from Limpopo and KwaZulu Natal provinces in South Africa , and Sofala Province in Mozambique ( Chopard 1935 ). It is likely, however, that the distribution of this species extends further north in Mozambique . These katydids are found in savanna and woodland habitats covered with tall, robust grass species, such as Pennisetum purpureum Schumach and Setaria megaphylla (Steud.) T. Durand & Schinz. They feed on grass seeds and flowers, in the process accumulating large amounts of fatty tissue in their abdomen, a characteristic shared with other species of Lanista and Pseudorhynchus , which allows them to survive for long periods without feeding (the holotype of L. africana carries a note “Lived 18 months without food.) For this reason, L. annulicornis is one of the few katydid species found frequently at the peak of the dry season when food availability is limited. Additionally, based on the fact that adults are found throughout the year, while nymphs are seen only during the rainy months (December to April), it is possible that adults survive multiple seasons. In Gorongosa this species is found from the lowlands up to ~ 900 m a.s.l. Bioacoustics. The call of L. annulicornis consists a series of short, two-impulse echemes (echeme duration 0.089 – 0.154 s; n=9), with peak frequency at 7.8 kHz, thus easily perceived by the human ear. Males also produce loud defensive stridulation if captured, similar in its characteristics to the advertisement call ( Figs. 46 J–L). Measurements ( 3 males , 2 females ). —body w/wings: male 54–56 (54.71.2), female 51–54 (52.52.1); body w/o wings: male 39–40 (39.7.6), female 33–39 (364.2); pronotum: male 11–12 (11.7.6), female 10–11 (10.5.7); tegmen: male 37–39 (37.71.2), female 35–37 (361.4); hind femur: male 15–18 (16.31.5), female 16–17 (16.5.7); ovipositor: 13–15 (141.4) mm.