Pistosia Weise, 1905

Sekerka, Lukáš, 2015, Wallacea, Pistosia and Neodownesia: three distinct genera and their tribal placement (Coleoptera: Chrysomelidae: Cassidinae), Acta Entomologica Musei Nationalis Pragae 55 (2), pp. 713-743 : 724

Pistosia Weise, 1905 , stat. restit.

( Figs 5–7 )

Pistosia Weise, 1905: 93 (original description); WEISE (1911a): 54 (catalogue); WEISE (1911b): 82 (catalogue, redescription); UHMANN (1956): 167 (comparative notes, key to Gonophorini genera); GRESSITT (1957): 301 (South Pacific fauna); UHMANN (1958): 229 (catalogue); UHMANN (1964): 461 (catalogue); WÜRMLI (1975):50 (synonymy with Wallacea and Neodownesia ).

Estigmena [misidentification]: GRESSITT (1957): 210 (South Pacific fauna).

Type species. Pistosia maculata Weise, 1905 , by monotypy.

Other species included. Alurnus testaceus Fabricius, 1801 and Estigmena terminalis Baly, 1869 .

Differential diagnosis. Pistosia can be readily distinguished from other genera by combination of tubular antennae and absence of the scutellar row of punctures. Neodownesia and Wallacea differ in submoniliform basal antennomeres, antennomere III approximately 1.5× as long as II (three times longer in Pistosia ), mandibulae with teeth (with cutting edge in Pistosia ), normally sized labrum (very small in Pistosia ), disc of pronotum flattened and coarsely punctate (convex and only basally punctate in Pistosia ), vertex strongly convex and coarsely punctate (sparsely punctate and flat in Pistosia ). Bothryonopa and Macrispa have tubular antennomeres, mandibles with cutting edge and small labrum like Pistosia but differ in presence of the scutellar row of punctures (absent in Pistosia ), glabrous elytral epipleura (pubescent in Pistosia ), and convex and moderately to coarsely punctate vertex (flat and very finely punctate in Pistosia ). Macrispa also differs in compeletely irregular punctation of the elytra while Pistosia has regular punctation of elytra.

Biology and host plants. The host plants of Pistosia are unknown, however, it is likely that the genus is associated with Arecaceae like Bothryonopa and Wallacea species. There is some support for this idea as all three collectors, LABILLARDIÈRE (1802), WALLACE (1869) and SARASIN & SARASIN (1905), mentioned in their reports seeing extensive stands of palms. Labillardière even collected some as herbarium vouchers, and Wallace obtained insects from them.

Remarks. WEISE (1905) proposed the genus for a single species from Sulawesi. Latter on, UHMANN (1957) transferred a second species to Pistosia . WÜRMLI (1975) synonymized Wallaceana with Pistosia and confirmed synonymy of Neodownesia with Wallaceana ignoring all morphological features and WEISEʼs (1905, 1911b) comparative notes pointing to the strong difference in formation of antennae. Since then Pistosia was applied to all species previously classified in Wallaceana and no reference truly refers to Pistosia in the sense of the type species.

Figures

Figs 1–7. 1 – Neodownesia mediovittata (Gestro, 1920) (Laos: Ban Song Cha, J, 8.7 mm); 2 – N. rubra Gressitt, 1953 (holotype, J, 6.5 mm); 3 – N. sita (Maulik, 1919) (Thailand: Soppong, ♀, 9.0 mm); 4 – Wallacea apicalis Gestro, 1896 (Indonesia: Mentawai Is.: Siberut, 5.3 mm); 5 – Pistosia terminalis (Baly, 1869) (holotype, 9.5 mm, © Natural History Museum, London); 6 – P. maculata (syntype, 12.0 mm, © Museum für Tierkunde, Berlin); 7 – P. testacea (Fabricius, 1801) (Indonesia: Sulawesi: Ahua Creek, 11.1 mm).