Pyrgauchenia tristaniopsis Stegmann & Webb, 2002

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 : 295-299

Pyrgauchenia tristaniopsis Stegmann & Webb sp. nov.

(®gures 1A±F, 6, 7)

Diagnosis

Anterior process of pronotum moderately broad and bent backwards with comparatively large distal lobes in males but small distal lobes in females, the latter represented by two morphs. The male genitalia are similar to P. colorata , but can be distinguished by the aedeagus having (i) an invisible or minute gonopore (®gure 6K), (ii) more elongate and slightly bent apical region of the shaft above the gonopore in lateral view (®gure 6J), and (iii) a more slender outline of the aedeagus in posterior view (®gure 6I).

Description

Length:, 5.6±6.5 mm (seven specimens) (mean 6.0 mm);, 5.7±6.3 mm (eight specimens) (mean 6.0 mm). Length of anterior process:, 4.3±5.4 mm (mean 4.7 mm);, 3.5±3.9 mm (mean 3.7 mm).

Colour. Male: uniformly dark brown except for base of posterior process and tibiae, yellow-ocracheous, and a hyaline spot near the tip of clavus (®gure 6A). Female: same as male (®gure 6B) or with pronotum and spots on the tegmen ochraceous (®gure 6H).

Pronotum. Male: anterior process moderately bent posteriorly and moderately broad in lateral view (®gure 6A); point A not pointed (®gure 6C); lateral carina near to anterior margin, especially so towards point A (®gure 6C); distal end of anterior process at about 45ss (®gure 6A, C); subapical node low and indistinct (®gure 6A). Female: there are two morphs diOEering from the male by the following characters: anterior process either about 1 mm shorter than in the male with its distal lobes much smaller and more slender (®gure 6B, D) or anterior process strongly curved posterio-ventrall y in a spiral with its distal end angulate, orientated vertical to anterior-dorsal relative to long-body axis (®gure 6F±H) and its tip broadened or heart-shaped (®gure 6G); in both female morphs the subapical node is distinct and higher than in the males (®gure 6B, H).

Genitalia. Male: shaft of aedeagus moderately broad in posterior view (®gure 6I), its tip slightly bent anteriorly and its posterior margin, below gonopore, strongly convex, in lateral view (®gure 6J); gonopore, when visible, minute (®gure 6K); apical part of posterior part of style long (®gure 6L), its apex bent medio-ventrally and tapering to a subacute tip (®gure 6L, M).

Nymphs. The ®ve nymphal stages are distinguished thus (for changes in width of prothorax see table 3):

1st Instar: Length approximately 1.2 mm with increasing abdominal expansion of older individuals. No projection on the pronotum (®gure 7A); no tergal extensions of the 6th to 8th abdominal segments (®gure 7B); 9th segment with a short projection dorsal and two projections ventral to the anal tube (®gure 7A, B).

2nd Instar: Length approximately 2.2 mm. Slight, but distinct projection on the pronotum (®gure 7C); slight extensions of the 6th to 8th abdominal segments (®gure 7D); projections of the 9th segment become progressively longer in this and the following stages (®gure 7D).

3rd Instar: Length approximately 2.8 mm. Pronotal projection conspicuous (®gure 7E); extensions of the 6th to 8th abdominal segments distinct (®gure 7F).

4th Instar: Length approximately 3.4 mm. Pronotum triangular and tapering in lateral view (®gure 7G); extensions of the 6th to 8th segments long (®gure 7H).

5th Instar: Length approximately 4.9 mm. Pronotum with a distinct posterior process with its dorsal margin curved convexly in females (®gure 7K) and nearly straight in males (®gure 7J); anterior margin of pronotum convexly bent in both sexes; males with a spatulate margin on the pronotum (®gure 7J), indistinct in females (arrowed in ®gure 7K); long, spine-like abdominal extensions (®gure 7I). Head with two dorsal projections (®gure 7L).

Distribution Mt Kinabalu (Sabah, Malaysia).

Material examined

HOLOTYPE ,, Malaysia, Sabah, Kinabalu National Park Headquarters (6ss01¾N, 116ss33¾E), 1500 m, leg. U. E. Stegmann, 15 December 1998 ( BMNH) . PARATYPES, 3, same data as holotype; 4, 8 , same data as holotype except 17 and 26 April 1996, and 3 February, 26 April and 16 November 1997 (all BMNH, DEI) .

Remarks

This species is known from only one population at 1410±1610 m at the headquarters area on Mt Kinabalu, although its host-plants were also found at higher (up to 2000 m) and lower elevations (1150 m). This indicates a speci®c altitudinal range. There are two female morphs, with or without a strongly curved pronotal process (see description of pronotum above); polymorphisms of this type are rare within the Membracidae ( Wood, 1976; Carroll and Loye, 1986). Although in the type series, females with or without a strongly curved pronotal process are ochraceous or brown in colour, respectively, the reverse situation was also noted in the ®eld population.

This species was found on many host-plant species and families ( table 4). Eggs were deposited and guarded as in P. biuni . Most aggregations of nymphs and adults were visited by a Myrmicaria sp. but some others by Camponotus sp. , and Prenolepis 1st instars 2nd instars 3rd instars 4th instars 5th instars

0.49Ô 0.03; 13 0.7Ô 0.03; 11 0.9Ô 0.04; 14 1.14Ô 0.07; 11 1.49Ô 0.09; 10 Flacourtiaceae Flacourtia kinabaluensis Sleum.

Lauraceae Lindera pipericarpa Boerl.

Melastomataceae Melastoma malabathricum Linn.

Myrtaceae Tristaniopsis clementis (Merr.) Wilson & Waterhouse Rosaceae Rubus moluccanus Linn.

Rubiaceae Nauclea ?bernardoi Merr.

Uncaria sp.

Wendlandia sp.

Theaceae Adinandra excelsa Korth.

Urticaceae Debregeasia longifolia Wedd.

Pouzolzia sanguinea (Blume) Merrill

sp. The name of this species is derived from of the host-plant Tristaniopsis clementis (Merr.) Wilson & Waterhouse on which it was found for the ®rst time.