Stolas diversa ( Boheman, 1850 )

Sekerka, Lukáš, 2016, Taxonomic and nomenclatural changes in Cassidinae (Coleoptera: Chrysomelidae), Acta Entomologica Musei Nationalis Pragae 56 (1), pp. 275-344 : 331-332

Stolas diversa ( Boheman, 1850)

Mesomphalia diversa Boheman, 1850: 243 (original description).

Mesomphalia fossulata Boheman, 1850: 241 (original description), syn. confirm.

Mesomphalia vidua Boheman, 1850: 242 (original description), syn. nov.

Type localities. Mesomphalia diversa : ‘Brasilia’; M. fossulata : ‘Brasilia’; M. vidua : ‘Buenos Ayres’.

Type material. Mesomphalia diversa : LECTOTYPE (designated by BOROWIEC 1999a): ♀, pinned: ‘ Rio Jan [w, p, s] || F. Sahlb. [w, p, cb] || Type. [w, p, s] || TYPUS [pi, p, cb] || 53 | 65 [hw] [pi, p, s] || LECTOTYPE | des. L. Borowiec [r, p, cb] || Stolas | (s. str.) | diversa | Det. M. Viana – (Boh.) [w, hw, cb] || X-1965 [hw on underside of previous label] || NHRS-JLKB | 000022667 [w, p, cb]’ ( NHRS). PARALECTOTYPE: ♂, pinned, ‘ Brasil [w, p, s] || Bhn. [w, p, s] || PARATYPUS [orange, p, cb] || 54 | 65 [hw] [pi, p, s] || PARALECTOTYPE | des. L. Borowiec [r, p, cb] || Stolas | (s. str.) | diversa | Det. M. Viana – (Boh.) [w, hw, cb] || X-1965 [hw on underside of previous label] || NHRS-JLKB | 000022668 [w, p, cb]’ ( NHRS).

Mesomphalia fossulata : LECTOTYPE (designated by BOROWIEC 1999a): pinned, ‘11088 [w, p, s] || fossulata | Bohem | Bras. v.Olf. [g, hw, cb] || LECTOTYPE | des. L. Borowiec [red, p, cb] || LECTOTYPUS | Mesomphalia | fossulata | Boheman, 1850 | des. L. Borowiec [red, p, cb, bf]’ ( ZMHB) ; PARALECTOTYPES: 2 spec., pinned, ‘ PARALECTOTYPE | des. L. Borowiec [red, p, cb] || PARALECTOTYPUS | Mesomphalia | fossulata | Boheman, 1850 | des. L. Borowiec [red, p, cb, bf]’ ( ZMHB).

Mesomphalia vidua : HOLOTYPE: ♀, pinned (missing both antennae), ‘E. Coll | Chevt. [w, p, cb] || Type [w, p, s, rf, circle label] || Mesomphalia | vidua Chv Bhn | Bayres type [w, hw by Chevrolat, s] || Vidua | Chv | Brasilia | B. ayres [w, hw, s] || 67·56 [w, p, s]’ ( BMNH).

Remarks. BOROWIEC (1999a) synonymized Mesomphalia fossulata with M. diversa without further comments,. However, prior to the synonymy he studied types of both taxa and provided both with lectotype designation. I have reexamined these types and concur with the proposed synonymy. Stolas diversa belongs to the group of species characterized by metallic elytra with large dull punctures and spots of dense vestiture but it is readily separated by strongly gibbous elytra while the remaining species have either postscutellar tubercle or weakly convex elytra.

During my stay in BMNH I studied type of Mesomphalia vidua , which was unknown to preceding authors. Boheman positioned systematically M. vidua between the M. fossulata and M. diversa and used for description presumably only a single specimen because he described quite unusual features for this species group (black dorsum and elytra without spots of vestiture and large dull punctures) resulting from the poor condition of the specimen. The specimen must either have been old individual when collected or was damaged subsequently. The unnaturally black colouration resulted from the fat-body penetrating the elytra and also covered the large dull punctures, which are still present, but hardly visible. The typical spots of vestiture were mostly rubbed away and partly immersed in fat; as a result only a few setae remain clearly visible. Otherwise the specimen has the same shape and convexity of elytra as S. diversa and thus I synonymize M. vidua with the latter species. Since both taxa were described in the same publication I followed the Principle of the first reviser ( ICZN 1999: Article 24.2) and chose the name S. diversa as the valid one because it was more frequently used in literature and is based on well preserved type specimens.

It is also somewhat curious that M. vidua was described from Buenos Aires as large species of Stolas are primarily distributed in the tropical Brazil and reach Argentina only marginally. Most of the species occurring in Argentina were recorded from subtropical provinces of Misiones and Corrientes with no dry season. Already BURMEISTER (1870) doubted the origin of M. vidua and stated that he never saw any specimen from Argentina. He also stated that many specimens from this region were received via Buenos Aires but actually were not collected there and that this could also be the case with M. vidua , which instead might originae from Corrientes or Paraguay. SPAETH (1914) adopted these possible localities and since then they were listed as the distribution of M. vidua . However, BURMEISTER (1870) only supposed that these might be the areas were the specimen was collected and hence I do not adopt them in species distribution and occurrence of S. diversa in Argentina is considered as doubtful.

Distribution.? Argentina ( BOHEMAN 1850) and Brazil: Mato Grosso ( BOROWIEC 1996) and Rio de Janeiro ( BOHEMAN 1850, BOROWIEC 2002, FLINTE et al. 2009).