A new tibial gland in male spittlebugs with descriptions of two new species of Augustohahnia Schmidt (Hemiptera: Cercopidae) from New Guinea

Abstract

A new secondary sex character, here named the ‘tibial gland’, found on the forelegs of the males of a new spittlebug species, Augustohahnia dilatitibia sp. nov. (Hemiptera: Cercopidae) from New Guinea, is reported for the first time. The males of Augustohahnia dilatitibia sp. nov. are very distinct and unusual in having remarkably swollen fore tibiae with flat, bare and smooth prolateral surfaces. Scanning electron microscope observations revealed that the prolateral surface of the swollen fore tibiae is covered with numerous, very fine pores, with a density of 0.0068–0.0076 pores/μm². The distance between the pores varies between 4.04 and 10.77μm. Each pore unit is composed of a deep cavity in which one central sponge-like, grooved disc is set. The opening of the cavity is c. 5.20–5.78 μm in diameter. The central, sponge-like disc in the cavity has a sponge-like apex with 55–65 longitudinal grooves and measures 4.34–4.55 μm in diameter. There are also one to three fine, nearly ellipsoidal pits (c. 0.35–0.48 μm wide and 0.62–0.85 μm long) on the marginal cuticle rim surrounding the central sponge-like disc. These pores are presumed to be male pheromone-producing glands. If so, this represents the first report of a possible male pheromone structure in cercopid spittlebugs. Two new species of the spittlebug genus Augustohahnia Schmidt (Hemiptera: Cercopoidea), A. dilatitibia sp. nov. and A. sanguinifrons sp. nov., both from New Guinea, are described and illustrated. A key to the four known species in Augustohahnia is provided.