Thuris binodosus (Goding) McKamey, Stuart H. & Porter, Mitchell J., 2016

McKamey, Stuart H. & Porter, Mitchell J., 2016, First Immature of the New World Treehopper tribe Thuridini (Hemiptera, Membracidae, Smiliinae) with a new synonym, a new combination, and a new country record, ZooKeys 557, pp. 85-91 : 87-88

Taxon classification Animalia Hemiptera Membracidae

Thuris binodosus (Goding) comb. n.

Parantonae binodosa Goding 1926: 108 (Figs 1-4, 8; holotype USNM)

Thuris depressus Sakakibara 1975: 843, syn. n. (Figs 5-7; holotype DZUP)

Notes and new distribution.

Examination of the holotype of Parantonae binodosa Goding (1926), from Tena, Ecuador (Napo Province) (Figs 1-4) revealed a match with the holotype of Thuris depressus Sakakibara (1975) (Figs 5-7), resulting in the classification above. An aggregation of the species has also been observed in Ecuador in Coca (= Puerto Francisco de Orellana, Napo Province) and a solitary adult was found in (Fig. 8) Otoyaku, Santa Clara (Pastaza Province). The Venezuelan Thuris specimen (of Thuris fenestratus Funkhouser) was collected in Amazonas state.

Description of fifth instar

(Figs 9-11).

Diagnosis.

Body densely covered with short setae, but lacking chalazae and scoli; apex of abdominal segment IX narrowly extended ventrally far beyond dorsal extension.

Description.

Overall body. Length 2.50 mm, maximum width 1.25 mm. Cross-section of abdomen subcircular; chalazae on thorax and abdomen absent; waxlike substance absent; dorsal contour of abdomen in lateral view curvilinear (Fig. 10); overall body in dorsal view elongate (distinctly longer than wide). Coloration a combination of black and brown, most pale on premetopidium, metanotum, margins of tibia, and mid dorsally from pronotum to abdominal tergum VIII. Head. Scoli, dorsal or anterior rounded protuberances, and chalazae absent; compound eye surface setae present; frontoclypeus not extending over central margin of eye. Prothorax. Premetopidium and postmetopidium scoli absent; metopidial sulcus deeply incised; posterior extension of pronotum acute, surpassing posterior margin of metanotum but not attaining abdominal apex; dorsal pronotal single medial, suprahumeral, and humeral horn buds absent; pronotal lateral margin straight. Mesothorax. Dorsal projections absent; forewing pad anterior costal margin form straight, surface and costal chalazae absent. Metathorax. Dorsal projections absent. Legs. Tibia without chalazae; prothoracic tibia form subcylindrical, without defined margins; metathoracic tarsal length longer than pro- and mesothoracic tarsal length; pro- and mesothoracic first tarsomeres distinctly shorter than their second tarsomeres (Fig. 9); metathoracic first tarsomere subequal in length to its second tarsomere (Fig. 10). Abdomen. Terga III-VIII ventrolateral margins without enlarged chalazae or other lateral extensions, lateral longitudinal rows of enlarged chalazae or scoli between mid dorsal line and ventrolateral margins not manifested. Segment IX. Distal half tubular in cross-section; dorsal length subequal to length of segment V-VIII; dorsal projections before and at apex absent; ventral extension narrow and distinctly longer than dorsal extension (Fig. 10); fused portion of segment IX distal to unfused portion; unfused portion distally not bifurcate.

Discussion.

The nymph of Thuris binodosus is exceptionally devoid of the chalazae and scoli that adorn most treehopper nymphs, including those of the related tribe Tragopini , and that is in itself distinctive. Another diagnostic feature is the ventrally extended abdominal tergum IX, which among other membracid immatures only occurs in a few taxa. Although the ventral extension is distinctly longer than the dorsal extension in Todea cimicoides (Coquebert) and Colisicostata albata (Tode) of Tragopini , Phormophora maura (Fabricius) of Polyglyptini , and most Aetalionidae , only in Neotynelia Creão-Duarte & Sakakibara (2000; Amastrini ) is the extension digitiform as in Thuris binodosus . This digitiform ventral extension feature was not used in the phylogenetic study by Dietrich et al. (2001) and, perhaps because of this, Thuris did not form a clade with Amastrini . Neotynelia differs in always bearing large scoli on the abdomen at least (Fig. 12). Deitz (1975) established Thuridini as a tribe based in large part on the absence of cucullate setae in metathoracic tibial row I. Unfortunately, these basally covered setae so ubiquitous among membracid adults are absent in the nymphs. The subequal lengths of the metathoracic first and second tarsomeres, due to an extraordinarily long first tarsomere, is unusual but shared with other taxa such as Tragopini (McKamey et al., in prep) and is reflected in the similarly long first tarsomere (of three total) in Thuris adults.

Specimens examined.

Parantonae binodosa holotype (USNM). Thuris fenestratus Funkhouser holotype (USNM). Additional material of Thuris binodosus : 1 nymph. ECUADOR: Napo, Coca 24-VIII-1988, C. H. Dietrich #86, INHS Insect Collection 776, 690 (INHS). Not examined but same collection lot as examined nymph: 1 nymph, 1 adult (INHS), 2 nymphs, 3 adults (NSCU). Specimens of Thuris fenestratus : 1 adult. VENEZUELA: T. F. Amazonas, San Carlos de Rio Negro, 24-I-1985, P. & P. Spangler, R. Faitoute, W. Steiner (USNM).