Orexita postica ( Boheman, 1855 )

Sekerka, Lukáš, 2016, Taxonomic and nomenclatural changes in Cassidinae (Coleoptera: Chrysomelidae), Acta Entomologica Musei Nationalis Pragae 56 (1), pp. 275-344 : 313-314

Orexita postica ( Boheman, 1855) stat. restit.

Coptocycla postica Boheman, 1855: 95 (original description).

Coptocycla picta Boheman, 1855: 94 (original description); SPAETH (1911): 255 (synonymy), syn. confirm.

Coptocycla bifenestrata Boheman, 1855: 97 (original description), syn. nov.

Coptocycla maura Boheman, 1855: 98 (original description), syn. nov.

Type localities. Coptocycla bifenestrata : ‘Brasilia’; C. maura : ‘Brasilia’; C. picta : ‘Brasilia’; C. postica : ‘Brasilia’.

Type material examined. Coptocycla bifenestrata : LECTOTYPE (designated by BOROWIEC 1999a): pinned, ‘ Brasil [w, p, s] || Mhm. [w, p, s] || Type. [w, p, s] || NHRS-SRAH | 000022433 [w, p, cb]’ ( NHRS).

Coptocycla maura : LECTOTYPE (designated by BOROWIEC 1999a):pinned, ‘ Brasil [w, p, s] || Germ. [w, p, s] || Type. [w, p, s] || LECTOTYPE | des. L. Borowiec [r, p, cb] || NHRS-SRAH | 000022438 [w, p, cb] ’ ( NHRS). PARALECTOTYPE: pinned, ‘ Brasil [w, p, s] || Mhm. [w, p, cb] || PARALECTOTYPE | des. L. Borowiec [r, p, cb] || NHRS-SRAH | 000022439 [w, p, cb]’ ( NHRS).

Coptocycla picta : LECTOTYPE (designated by BOROWIEC 1999a): pinned, ‘ Brasil [w, p, s] || Westin. [w, p, s] || Type. [w, p, s] || LECTOTYPE | des.L.Borowiec [r, p, cb] || NHRS-SRAH | 000022440 [w, p, cb]’ ( NHRS). PARALECTOTYPES: 1 spec., pinned, ‘ Brasil [w, p, s] || Bhn. [w, p, s] || PARALECTOTYPE | des. L. Borowiec [r, p, cb] || NHRS-SRAH | 000022441 [w, p, cb]’ ( NHRS); 1 spec., pinned, ‘ Brasil [w, p, s] || Mhm. [w, p, cb] || NHRS-SRAH | 000022442 [w, p, cb]’ ( NHRS); 1 spec., pinned, ‘ Brasil [w, p, s] || Sommer [w, p, s] || NHRS-SRAH | 000022443 [w, p, cb]’ ( NHRS).

Coptocycla postica : LECTOTYPE (designated by BOROWIEC 1999a): pinned, ‘ Brasil [w, p, s] || Mhm. [w, p, cb] || Type. [w, p, s] || postica Dej. [w, hw by Boheman, s] || LECTOTYPE | des. L. Borowiec [r, p, cb] || NHRS-SRAH | 000022444 [w, p, cb]’ ( NHRS). PARALECTOTYPES: 1 spec., pinned, ‘ Brasil [w, p, s] || Mhm. [w, p, cb] || NHRS-SRAH | 000022445 [w, p, cb]’ ( NHRS); 1 spec., pinned, ‘ Brasil [w, p, s] || F. Sahlb [w, p, cb] || NHRS-SRAH | 000022446 [w, p, cb]’ ( NHRS).

Remarks. Species of Orexita display great colour variability of dorsal pattern and as a result some species were multiply described under different names. The genus was never revised and subsequent authors did not examine types of most taxa hence most species were only listed in catalogues (see BOROWIEC 1999a). The only complex treatment is SPAETH (1911) who proposed a key to the species known to him and described several additional species. In the same publication he considered O. postica as valid and stated that O. picta is related through colouration and cannot be considered as distinct species. Later on, SPAETH (1914) listed O. picta as valid species with the name postica as variety of it. Since that publication O. picta was used as valid name for this taxon.

This species varies from mostly yellow dorsum only with two black spots on the disc of pronotum and one spot on each humeral callus to nearly black dorsum with only W-shaped yellow spot on the anterior margin of pronotum. The pale forms (yellow with spots) were described as O. postica and O. picta and considered since SPAETH (1911) as synonyms, however, the dark forms were until now considered as valid species. Orexita bifenestrata has explanate margin of elytra with a large oval yellow spot around midlength on each side and yellow anterior margin of pronotum. Finally, O. maura is largely black only with a yellow anterior margin of pronotum. In my opinion all these taxa represent only colour morphs of a single species and there are many intermediate colourations.

All four names were proposed in the same publication just a few pages apart and I hereby synonymize all of them under the name O. postica which has priority over O. picta because of the Principle of the first reviewer ( ICZN 1999: Article 24.2), who was SPAETH (1911), and the other two names were listed only in catalogues.

Distribution. Argentina: Misiones ( BOROWIEC 2002); Brazil: Rio de Janeiro, Rio Grande do Sul, Sao Paulo ( BOROWIEC 1996), Minas Gerais, Santa Catarina ( BOROWIEC & TAKIZAWA 2011); Paraguay ( CHABOO 2002).