Podisus distinctus

Roell, Talita, Lemaître, Valérie A., Webb, Michael D. & Campos, Luiz A., 2023, An annotated and illustrated Type Catalogue of the predacious Shieldbugs (Hemiptera: Heteroptera: Pentatomidae: Asopinae) in the Collection of the Natural History Museum, London, Zootaxa 5232 (1), pp. 1-105 : 33-35

distinctus (Oplomus) Distant 1880: 30 . [ Figs 48–49 ]

Original data: “ Hab. MEXICO (coll. Sign.).” [syntype (s)]

NON-TYPE ♀: “Fry Coll. 1905-100”; “337”; “NHMUK 010937890” ( Fig. 48 ) .

NON-TYPE ♀: small square light-green label; “ distinctus Dist. [Distant’s handwriting]”; “Curtis.”; “Distant Coll./ 1911-383”; “NHMUK 010937891” ( Fig. 49 ).

Current status: Oplomus catena ( Drury, 1782) (synonymised by Thomas 1992: 57).

Notes: Thomas (1992: 57) synonymised Oplomus distinctus Distant, 1880 with Oplomus catena ( Drury, 1782) on the basis of two female specimens labelled “ Oplomus distinctus Distant ” located at NHMUK. Other than these and Drury’s original description, he may also have used the figure published by Distant (1880), which shows Thomas’s “angulate apices of the juga” (or, at least, one angled jugum and tylus), a diagnostic character for O. catena according to Thomas.

Only one measurement and “remainder wanting” could support the fact that there was only one specimen described, but we cannot be sure.

Herbert Zettel (pers. comm.) could not find type material of O. distinctus Distant in Vienna, where most of Signoret’s collection is located. He explained: “I could not find a type, or any specimen labeled as such. Among our specimens of O. catena there is only a single one with a colour pattern like the specimen illustrated in BCA, but it was collected by Natterer in Brazil.”

Aware that material seems to have circulated freely between Signoret and Stål (whose collection is now in NHRS, Stockholm), we perused the checklist of heteropteran species on the NHRS website ( Gustafsson 2006). We found listed “ distinctus Distant, 1880 Oplomus Pentatomidae ”. Since this is no longer a valid name, we reasoned that the material was historical and requested images from the curator, Gunvi Lindberg. Images were received of a specimen and its labels; the specimen matches Distant’s description well and its determination label is in Distant’s handwriting. We consider this specimen a syntype.

In NHMUK, we have located the two female specimens referred to by Thomas and determined by him as O. catena (listed above). Both match the syntype of O. distinctus in colour pattern, however in these specimens, as with the syntype found, the apices of the juga are not as markedly angulate as in Thomas’s (1992) or Distant’s (1880) figures. Neither of them bears a locality label. One is from Fry’s collection, the other one from Distant’s.

Apart from types of Lepidoptera at NHMUK, Dru Drury (1725–1803– or 1804)’s types are not easily identified since his collections of exotic and British insects were sold to various buyers in 1805 and in 1818, respectively; the latter as part of Edward Donovan (1768–1837)’s collection. With the example of the type of Hesperia busiris Fabricius, 1793 , described from Drury’s collection, Zilli & Grishin (2018) have certainly shown how best to locate types from Drury’s collection; indeed, they have given all references to do so.

The species O. catena ( Drury, 1782) , as currently understood, is extremely variable. In the same work, Drury described another species, Cimex regius , conceding, however, that it could be the opposite sex to C. catena . Indeed, Herrich-Schäffer (1851) figured a specimen of Asopus catena similar to Drury’s Cimex regius . Stål (1870: 27) listed and described four varieties under O. (Catostyrax) catena : var. a was catena Drury (1782: 65 ; pl. 46, fig. 1); var. b was regius Drury (1782: 66 ; pl. 46. fig. 6 = catena: Herrich-Schäffer, 1851: 337 ; pl. 323, fig. 1008); var. c had never been figured and var. d was militaris Herrich-Schäffer (1851: 336; pl. 323, fig. 1007).

Recently, Brugnera et al. (2019: 1049, 1051–1053) have recognized and figured four chromatic patterns for adults of Oplomus catena , much as Stål (1870: 27). However, their first pattern was an addition to Stål’s list while Stål’s var. a and var. b were represented in their second pattern (3g, h and 3e, f, respectively). In addition, Stål’s var. c was represented by pattern 4 and var. d, by pattern 3.

Brugnera et al. (2019: 1053) remarked that pattern 2 was the most common variation. Similarly, Berg (1891: 239) had specified that, among his Argentinian, Uruguayan and Paraguayan specimens, Stål’s var. b [ regius Drury ] was the most abundant. This may be why pattern 2 has historically and recently been the most used to illustrate the species (see also Costa Lima 1940, fig. 234 and Grazia et al. 2015, fig. 22.5a). Brugnera et al. (Ibid.) also noted that, in their sample, patterns 1 and 2 were represented by both sexes, whereas pattern 3 was represented only by females and pattern 4 by males (Stål also had recorded the sexes for the specimens he had: female for catena , male for regius [Pattern 2, both sexes, supporting Drury’s assertion], male for his var. c [Pattern 4] and female for militaris , his var. d [Pattern 3]).

The syntype located in NHRS, Stockholm and both NHMUK specimens examined by Thomas (all females) represent pattern 3 ( Brugnera et al. 2019: 3 k, l) while the image of a male reproduced by Lupoli (2019: fig. 2A) represents pattern 4. Based on the above, we confirm Thomas’s synonymy.

Distant was documenting Mexican and Central American species and may not have checked descriptions for South American ones. Even if he had, the figure of Asopus militaris by Herrich-Schäffer (1851: pl. 323, fig. 1007) could not have convinced him that the specimen(s) that Herrich-Schäffer had had in front of him was/were similar to the one(s) he used to describe O. distinctus . Images of the lectotype of Platynopus / Asopus militaris Herrich-Schäffer 1851 (Fernández de Bobadilla 2014) displayed on Wikimedia and taken at the Zoologische Staatssammlung M̧nchen (ZSM) confirm this.

Also, as Thomas (1992: 57), Distant (1880) knew that O. catena did not occur in Mexico since he did not list it (neither had Stål 1862b, whilst all specimens mentioned by Stål 1870 came from Rio Janeiro, Brazil). Granted, both Dallas (1851: 83) and Walker (1867a: 120) had recorded each a specimen from Mexico under the species O. catena but Dallas’s specimen was really found to be O. dichrous Herrich-Schäffer, 1839 , and Walker’s could not be found among specimens of Oplomus and may currently be standing under Perillus confluens . Furthermore, historical evidence would seem to confirm the Brazilian provenance of the two female specimens in NHMUK listed above. Indeed, despite the fact that the entry in the NHMUK Accessions register for 1905- 100 does not indicate a locality, it is well known that Alexander Fry (1821–1905) lived and worked many years in Rio de Janeiro, Brazil (see, for example, Murray 1868: 74). As for the small square light-green label on the specimen from Distant’s collection, it could refer to the Neotropical ecozone and “CURTIS.”, to the British entomologist John Curtis (1791–1862), whom we know had procured specimens from Brazil since he presented some to NHMUK in 1844 (See entry 1844- 87 in the Accessions Register). It would thus appear that the syntype found in NHRS, Stockholm was erroneously labelled “ Mexico.”; Distant could not have suspected this.

Finally, it is of some interest that Distant (1880) had noted the following difference between his new species, O. distinctus and all other Mexican and Central American Oplomus species that he had listed: “differs from all by the small dilation of the fore tibiae”; it was possibly then an innovative diagnostic feature. Brugnera et al. (2018: 20) have indeed concluded, concerning the Asopinae : “The foretibial expansion proved useful for species and genus level identifications, and was sexually dimorphic only in one of the studied species [ Euthyrhynchus floridanus (Linnaeus, 1767) ]”.

Figures

FIGURES 41–48. Type and non-type specimens deposited in NHMUK. 41–42, Platynopus conspersus; 43–46, Zicrona cuprea; 47, Macrorhaphis dallasi; 48, Oplomus distinctus. Scale bars: 4 mm.

FIGURES 49–56. Type and non-type specimens deposited in NHMUK. 49, Oplomus distinctus; 50–51, Coryzorhaphis dollingi; 52–55, Platynopus dotatus; 56, Blachia ducalis. Scale bars: 4 mm.