Dysdercus cinctus, Scudder, 1890

Kment, Petr, 2021, A review of the fossil taxa originally assigned to Pyrrhocoridae (Hemiptera: Heteroptera), Zootaxa 5081 (4), pp. 579-586 : 580

‘Dysdercus’ cinctus Scudder, 1890 and ‘Dysdercus’ unicolor Scudder, 1890

Dysdercus cinctus Scudder, 1890: 410 , pl. 24: figs 11, 13, 14 (original description, figures). Syntypes: 9 specimens (Nos 1426, 1745, 3199, 4248, 5865, 7161, 9890, 10303, 13561), USA, Colorado, Florissant Fossil Beds; Eocene: Chadronian (37.2‒ 33.9 Ma) (coll. Museum of Comparative Zoology, Harvard, USA —see Anonymus 2021a).

Dysdercus unicolor Scudder, 1890: 410 (original description). Syntypes: 2 specimens (Nos 3230, 10340), USA, Colorado, Florissant Fossil Beds; Eocene: Chadronian (37.2‒33.9 Ma) (coll. Museum of Comparative Zoology, Harvard, USA —see Anonymus 2021b).

Comments. Both species were described by Scudder (1890) from the Eocene Florissant Formation of Colorado, USA. Scudder (1890) noted that the examined specimens closely resembled species of Lygaeus Fabricius, 1794 (Lygaeoidea: Lygaeidae ) from the same beds, differing only in lack of ocelli, which is diagnostic for Pyrrhocoroidea , and assigned them to the genus Dysdercus Guérin-Méneville, 1831 , the only genus of Pyrrhocoridae occurring in the Americas. The figures provided by Scudder (1890) are of insufficient quality to accept or challenge his taxonomic hypothesis.

Pyrrhocoridae are primarily an Old World group, with all of its genus-group taxa occurring mainly in the Afrotropical and Oriental Regions, with a moderate diversity in the Palaearctic and Australian Regions (e.g., Schuh & Weirauch 2020). The only exception is the nominotypical subgenus of Dysdercus , which is shared between Africa (8 species— Freeman 1947, Stehlík 1965, Pierrard 1967) and the Americas (44 species—van Doesburg 1968; Schaefer 2013; Schaefer & Stehlík 2013; Zrzavý & Nedvěd 1997, 1999). Based on the cladistic analyses of morphological characters the Neotropical Dysdercus species represent a monophyletic group ( Zrzavý & Nedvěd 1997, 1999) which suggest they originate from a single transoceanic dispersal event from Africa to America and subsequent radiation. However, as there is no trace of deeper morphological divergence between the taxa, I hypothesise that such a dispersal event happened considerably later than in the Eocene (Chardonian 37.2‒33.9 Ma). The phylogenetic analysis of Sudakaran et al. (2015) indicates the divergence of African and Neotropical Dysdercus s. str. about 25 Ma. However, their analysis is based on very limited taxon sampling, the Dysdercus s. str. is found paraphyletic in regard to the mostly Oriental subgenus Paradysdercus Stehlík, 1965 , and finally they used the fossils of Dysdercus from the Florissant and Pyrrhocoris tibialis Statz & Wagner for dating of the analysis (see below). In this light, the placement of the Florissant fossils into Dysdercus , even in Pyrrhocoridae , seems highly doubtful.A revision of both species based on a re-examination of their type materials is urgently needed. In any case they are certainly not suitable candidates for calibration of molecular clocks in phylogenetic analyses, and their application as such should be avoided.