Ornithia Thomson 1864

Heffern, Daniel, Nascimento, Francisco E. De L. & Santos-Silva, Antonio, 2018, Descriptions, redescription, notes, and new ranks in American Cerambycidae (Coleoptera), Zootaxa 4531 (1), pp. 59-80 : 72-75

Ornithia Thomson 1864

Ornithia mexicana was originally described by Sturm (1843) as Ozodes mexicanus . A year later, Guérin-Méneville (1844) described the same species as Trichophorus chevrolatii , also from Mexico. In the same year, Chevrolat (1844) synonymized these species: “28. Ozodes Mexicanus, St. ( Trichophorus argentipictus, Chev. Cat. Dej. Trich. Chevrolatii, Guérin texte de l’Icon. du rég. animal Ins. p. 228).” White (1853), apparently, observed the synonymy proposed by Chevrolat (1844), and listed the following species as synonyms of Trichophorus chevrolatii (the first three, based on Dejean’s 1836 catalogue): T. sulphureosignatus Dupont ; T. croceinotatus, Chevrolat (female); T. argenteipictus Chevrolat (male); and Ozodes mexicanus Sturm. Nevertheless , considering the dates of Sturm (1843) and Guérin-Méneville (1844) as correct, evidently, Trichophorus chevrolatii is a junior synonym of Ozodes mexicanus , and not the opposite.

Thomson (1864) erected the genus Ornithia and followed the synonymies proposed by White (1853), considering the name T. chevrolatii as being the valid name of the species. During the time between White (1853) and Mason (1910), only Gemminger (1873) correctly reported Ornithia mexicana as the valid name of the species. It was only after Aurivillius (1912) that T. chevrolatii was finally considered as a synonym of Ornithia mexicana by all authors, except Tippmann (1960), who described Ornithia chevrolatii zapotensis . According to Tippmann (1960) O. chevrolatii and O. mexicana were described in the same year, and it was difficult to decide which had the priority.

Recently, Pérez-Flores et al. (2017) reported (translated): “ Ornithia —This monotypic genus is represented by O. mexicana ( Figure 5 ), which has 2 recognized subspecies, Ornithia m. mexicana and Ornithia m. zapotensis . The feature proposed to distinguish these subspecies is the coloration of the bands on the pronotum ( Tippmann, 1960). In O. m. mexicana , these bands vary from white to yellowish, while in O. m. zapotensis they are lemon yellow. The molecular results delimited 2 molecular taxonomic units, one for specimens with clearly clavate and white bands on the pronotum and elytra ( Figures 5C and D ); and another represented by specimens with yellow bands on the pronotum and elytra ( Figures 5A and B ). These results support the assignment of species for Ornithia previously proposed by Sturm (1843) and Tippmann (1960).” However, these statements encompassed serious mistakes. First, Tippmann (1960) did not establish the subspecies based only on pronotal pubescence; second, the color of the pronotal and elytral pubescence is notably variable, from distinctly white to distinctly yellow, with several degrees between these two extremes; third, all specimens of their figure 5 belong to Ornithia mexicana zapotensis ; and finally, and most important, the conclusions based on molecular analysis only separate males and females of O. m. zapotensis (males with femora distinctly clavate—their figures 5C and D—from females with femora less distinctly clavate—their figures 5A and B), and not the two subspecies.

As it is possible to see in the map ( Fig. 40 ), in western Mexico, nearly all specimens examined by us, or those which we received data from other collections, belong to O. m. zapotensis , while in eastern Mexico 100% of the specimens belong to O. m. mexicana . However, there are some specimens of O. m. mexicana collected in western Mexico, and a good amount in central Mexico. It is important to note that there are specimens of both subspecies collected in the same place in Mexico and Central America. The most southern specimen of O. m. zapotensis collected is from northern Nicaragua, while the most southern O. m. mexicana occurs near southern Panama.

Following the most common definition of subspecies, proposed by Mayr & Ashlock (1991): "an aggregate of phenotypically similar populations of a species inhabiting a geographic subdivision of the range of that species and differing taxonomically from other populations of that species," and considering that these populations are not reproductively isolated from each other ( Mayr, 1942), we would expect to see some hybridization in the contact zone (when it exists). However, we did not examine any specimen showing a hybrid form. Accordingly, it is not possible to consider O. zapotensis ( Figs. 38–39 ) as a subspecies of O. mexicana ( Figs. 25–37 ), especially because the subspecies would tend to disappear, especially in Southern Mexico and Central America, due to the lack of isolated areas of each subspecies. We also considered the possibility of O. zapotensis being just a variation of the typical form of O. mexicana . However, if O. zapotensis was a variation of O. mexicana , we would find specimens showing other elytral patterns, intermediate between the two “subspecies,, independently of the geographic area. Based on these considerations, we propose that O. zapotensis is a distinct species morphologically very close to O. mexicana . To reinforce this decision, although it is not conclusive evidence, we are providing photographs of two couples in copula ( Figs. 41–44 ), showing that each partner belongs to the same “subspecies.” The couples of O. zapotensis ( Figs. 43-44 ) were photographed in Nayarit, a Mexican state neighboring Jalisco, where O. mexicana also occurs. Based on this, we may suppose, (without complete certainty) that O. mexicana and O. zapotensis are reproductively isolated.

The most evident external differences between the two species are: scutellum surrounded by dense and isolated pubescence ( O. zapotensis ) / scutellum not surrounded by dense pubescence, or the pubescence is not isolated ( O. mexicana ); dense pubescence on basal half of the elytra forming two isolated maculae, the first one inclined toward humerus ( O. zapotensis ) / dense pubescence on basal half of the elytra forming a longitudinal band with anterior area curved inward ( O. mexicana ). The study of the male genitalia of both species showed no difference between them.

Figures

FIGURE 40. Map of distribution of Ornithia mexicana (circles) and O. zapotensis (triangles).

FIGURES 1–8. 1–4, Estoloides jaliscana, holotype female: 1, Dorsal habitus, 2, Ventral habitus; 3, Lateral habitus; 4, Head, frontal view. 5–8, Allotigrinestola nuevoleonis, holotype female: 5, Dorsal habitus, 6, Ventral habitus; 7, Lateral habitus; 8, Head, frontal view.

FIGURES 25–39. Dorsal habitus. 25–37, Ornithia mexicana: 25, male from Mexico; 26, male from Mexico (Chiapas); 27, male from Mexico (Puebla); 28, male from Costa Rica; 29, male from Mexico (Puebla); 30, male from Nicaragua; 31, male from Mexico (Veracruz); 32, male from Mexico (Veracruz); 33, female from Mexico (Puebla); 34, female from Mexico; 35, female from Costa Rica; 36, female from Mexico (Puebla); 37, female from Mexico. 38–39, Ornithia zapotensis, males: 38, from Nicaragua; 39, from Mexico (Nayarit).

FIGURES 41–44. Mating pairs. 41–42, Ornithia mexicana from Calakmul, Campeche, Mexico. 43–44, Ornithia zapotensis from San Blas, Nayarit, Mexico.