Pyrgauchenia Breddin

Stegmann, U. E., Webb, M. D. & Linsenmair, K. E., 2002, New species, synonymies and life-histories in the South-East Asian treehopper genus Pyrgauchenia Breddin (Auchenorrhyncha: Membracidae: Centrotinae), Journal of Natural History 36 (3), pp. 279-303 : 283-284

Pyrgauchenia Breddin

Pyrgauchenia Breddin, 1901: 126 . Type species: P. sarasinorum Breddin.

Pyrgophyllium Breddin, 1902: 91 . Type species: P. foersteri Breddin. Synonymized by Schmidt, 1906: 369 ±370.

Pyrgolyrium Breddin, 1902: 92 . Type species P. foersteri Breddin. Synonymized by Breddin, 1902: 92.

Hypsophyllium Schmidt, 1926: 22 . Type species H. jugulata Schmidt. Synonymized by Goding, 1931: 310.

Identi W cation of genus

For the generic placement of the new species described here we rely on the most recent description of the genus Pyrgauchenia and generic key by Funkhouser (1951: 215). This description contains the following diagnostic characters: presence of a subapical node (®gure 2B, arrowed); apex of head unilobed`truncate’ (or`spatulate ’; Goding, 1931) (®gure 1A, arrowed); anterior process recurved; tegmen with apex obliquely truncate and venation`normal’, i.e. with ®ve apical and two discoidal cells (®gure 1B). These characters are found in other genera but their combination is unique to Pyrgauchenia . It should be noted that the number of tegminal cells varies intraspeci®cally, sometimes diOEering among the two tegmina within one individual, i.e. there may be one to three discoidal cells and ®ve or six apical cells. As in other Hypsaucheniini, the pronotum is extended into an anterior process, a posterior process touches the tegmina, and suprahumerals are lacking ( Funkhouser, 1951). Funkhouser (1951) revised and provided a key to all valid Hypsaucheniini genera, except for Hybanda Distant (1908) which lacks the subapical node occurring in the new species described here.

Identi W cation of species

Some di culty was experienced in identifying the ®eld-collected specimens for this study. This was due to the similarity between species in the shape of the male genitalia (the source of critical characters in other Auchenorrhyncha families), the lack of workable keys (e.g. Goding, 1950), and intraspeci®c variation in the shape of the anterior process (sometimes missing). In addition to the above, we found that individuals of a species varied considerably, in both external characters and in the male genitalia, especially in the lengths of the anterior parts of the aedeagus and the style. Su cient`gap’ exists between these extremes, however, to recognize the species when all characters are taken together. To show these variabilities we have ®gured both extremes of the variation for each species. Despite strong intraspeci®c variation in the degree of sclerotization of the male genitalia, due to specimens being mostly taken from aggregations of teneral as well as mature adults, this variation is independent of other morphological variation. Our specimens were compared with the types of all nominal species that could not de®nitely be excluded by the original descriptions alone (see below).

We found several characters common to the species studied which, to our knowledge, have not been described for other Centrotinae so far. They are mentioned here for their potential use in future generic or higher-order-taxa revisions:

(1) The male pygofer has a separate dorso-posterio r process (®gure 1C, arrowed) that articulates via a membrane with the pygofer.

(2) The female pygofer has a dorsal and a ventral process (®gure 1F, arrowed) without membranous articulation.

(3) The second valvulae are moderately broad in lateral aspect. Proximally, the ventral margin curves above the ramus in lateral view (broken line in ®gure 1E).

(4) Long tergal projections in the ®nal instar nymphs of P. biuni , P. pendleburyi and P. tristaniopsis extend laterally on both sides of the 6th to 8th abdominal segments (®gure 7I); P. colorata lacks the projections on the 6th and 7th abdominal segments, but those on the 8th segment are much longer and directed posteriorly (®gure 1K).

(5) The 9th abdominal segment in the ®nal instar nymph bears a singular process dorsal to the anal tube and a bifurcated process ventral to the anal tube (®gure 7I, J); these processes are much smaller in P. colorata (®gure 1K).

(6) The pronotum of the ®nal instar nymph has a more or less tapering dorsal extension and a distinct posterior process (®gures 1G±J, 1L, M, 7J, K). Both sides of the pronotum bear a spatulate margin, presumably marking the position of the internal distal lobe-primordia (e.g. ®gure 1G, arrowed). In species with small or lacking distal lobes in adult females ( P. tristaniopsis and P. colorata , respectively), this margin is reduced (®gure 7K, arrowed) or lacking (®gure 1I) in nymphal females.