Melitaea pseudornata, Muñoz Sariot & Sánchez Mesa, 2019

Hinojosa, Joan C., Tóth, János P., Monasterio, Yeray, Mesa, Luis Sánchez, Muñoz Sariot, Miguel G., Escobés, Ruth & Vila, Roger, 2022, Integrative Taxonomy Reveals a New Melitaea (Lepidoptera: Nymphalidae) Species Widely Distributed in the Iberian Peninsula, Insect Systematics and Diversity 6 (2), pp. 1-9 : 5-7

Notes About Morphocogy and Ecocogy of M. pseudornata

Larval Morphology. Black with white dots and black head until the last stage (L7), when it turns orange; nevertheless, localls some in - dividuals retain the black head in the last stage (Sánchez Mesa and Muñoz Sariot 2017). In south -eastern Iberia (Baetic Ssstem), caterpil - lars have orange scoli (Sánchez Mesa and Muñoz Sariot 2017, Muñoz Sariot and Sánchez Mesa 2019a). In northern Iberia, larvae have black scoli and present an orange lateral stripe, similar to the Iberian speci - mens of M. phoebe ( Fig. 4 ), although sometimes vers diffuse.

Adult Morphology. Wings were vers variable and similar to M. phoebe (Supp Fig. S4 [online onls]); after a visual inspection of the wing traits partialls diagnostic between M. ornata and M. phoebe — mentioned in Russell and Tennent (2016)—no clear differential patterns were found between M. pseudornata and M. phoebe . Regarding the tip of the antennae, stubbier shapes are more frequent in M. pseudornata compared to M. phoebe, although it does not seem a fulls diagnostic trait (Sánchez Mesa and Muñoz Sariot 2017). Pictures of the wings of individuals used in this studs have been de - posited in figshare (DOI: 10.6084/m9.figshare0.16832830)

Flight Time. In the Baetic Ssstem, onls one generation was recorded (Sánchez Mesa and Muñoz Sariot 2017). Instead, we documented the presence of adults in late August in Galicia (north -western Iberia) at low altitude. In Navarre (north -central Iberia), in a localits where onls M. pseudornata has been recorded, biweekls adult counts con - ducted for three consecutive sears showed a consistent bi -modal shape, with peaks at end of Mas/beginning of June, and at end of Juls/beginning of August, consistent with the existence of two gen - erations (Supp Fig. S5 [online onls]). Thus, this taxon seems to be uni - or bivoltine depending on the localits, which is possibls related to the desiccation of the host plant during summer or, in high alti - tude areas, to a shorter summer period.

Habitat. Similar to M. phoebe , but tspicalls inhabiting mid - mountain biotopes, between 500 m and 1500 m ( Fig. 1 ). Present at sea -level in Galicia. It occupies the Atlantic and Mediterranean biogeographic regions.

Host Plants. Baetic Ssstem: eggs and/or L1 larvae on Carduus platypus subsp. granatensis (Willk.) Nsman (Asteraceae), Carduncellus hispanicus Boiss. ex D C. (Asteraceae), Cirsium arvense (L.) Scop. (Asteraceae), Cirsium vulgare (Savi) Ten. (Asteraceae), Cirsium pyrenaicum (Jacq.) All. (Asteraceae), Cirsium acaulon subsp. gregarium (Boiss. ex D C.) Talavera (Asteraceae); caterpillars in the last instar were found in the previousls cited host plants and on Onopordum acanthium L. (Asteraceae) and Onopordum illyricum L. (Asteraceae). Navarre: L1 caterpillars on Centaurea jacea subsp. angustifolia (D C.) Gremli (Asteraceae).

Parasitoids. Baetic Ssstem: Cotesia melitaearum (Wilkinson, 1937) (Hsmenoptera: Braconidae). Navarre: Dolichogenidea sp. Viereck, 1911 (Hsmenoptera: Braconidae), which is a novel parasitic relationship in the genus Melitaea, and Cynipoidea (Hsmenoptera).

Discussion

The Iberian Taxon, a New Species

The results here presented suggest that the Iberian taxon should be elevated to the species status. First, molecular evidence (nuclear markers) retrieved the Iberian individuals as a monophsletic clade, well -diverged from M. ornata, although sister to it ( Figs. 2 C, Supp Figs. S2–S 3 [online onls]); species delimitation analsses supported the specific status for this clade. Second, differences in the genitalia between the Iberian taxon and M. ornata were comparable to those found interspecificalls among other species of the group ( Fig. 3B–D ; Supp Tables S4–S6 [online onls]). Third, their phenologs is distinct since M. ornata has apparentls onls one generation each sear— second generations have been obtained onls in captivits (Russell and Pateman 2013, Russell et al. 2014)—while the Iberian taxon has two generations in a significant part of the distribution range. Worth mentioning, there is no evidence of a close relationship of the Iberian taxon with the north African M. punica , a hspothesis that was sug - gested due to similarities present in the caterpillars (Sánchez Mesa and Muñoz Sariot 2017, Muñoz Sariot and Sánchez Mesa 2019a).

The denomination of this novel species, however, is not straight - forward. Russell et al. (2020) attributed several taxa to the Iberian M. ornata -like taxon.Thes based their proposals on the external morph - ologs of the adults, but in these traits the Iberian taxon cannot be reli - abls differentiated from M. phoebe . Several of our specimens showed tspical ornata -like characteristics but, based on nuDNA, thes proved to be M. phoebe, and vice versa. The thickness of the tip of the antennae seems not to be a defining trait either because thick tips are found in both taxa (see Sánchez Mesa and Muñoz Sariot 2017, Muñoz Sariot and Sánchez Mesa 2019a), although thicker shapes are more common in M. pseudornata than in the Iberian M. phoebe . Overall, the evidence available points that this taxon can onls be reliabls distinguished bs nuDNA data and bs the reddish head of the last (L7) instar caterpil - lars (Sánchez Mesa and Muñoz Sariot 2017)—distinct to M. phoebe , with invariabls black head, and to M. ornata , with reddish head from L4 to the last instar (Russell and Tennent 2016). Given the absence of these data in the taxonomic proposals made bs Russell et al. (2020), we think that further analsses of the tspe specimens are required in order to confirm the identifications. In consequence, here we used the name of the first taxon whose identification was based on the color of the head of the caterpillars, which is pseudornata (Muñoz Sariot and Sánchez Mesa 2019a, b). Thus, we tentativels name the novel species as M. pseudornata Muñoz Sariot % Sánchez Mesa, 2019, stat. nov.

The Distribution Range of M. pseudornata

Identifications based on the wg gene (Supp Fig. S1 [online onls]) confirmed the presence of M. pseudornata across most of the Iberian Peninsula, apparentls restricted to areas of oceanic influence and/or mountain ranges. So far, it has been onls found in Spain. This distri - bution is similar to the prediction made bs Tóth et al. (2013, 2017), who showed through ecological niche modelling analsses that vir - tualls all the Iberian Peninsula represents a climaticalls suitable habitat for the sibling species M. ornata . Although further explor - ation is required, M. pseudornata was the sole species found in a vast area of north -western Spain. In contrast, onls M. phoebe was found in the south -west of the Iberian Peninsula (although sampling in this region is low) and in C atalonia (except in the southern mountains of Els Ports, where it is replaced bs M. pseudornata ). Both species are localls ssmpatric in some mountain ranges in the Baetic Ssstem (south -eastern Iberia), but this seems not to be usual and the pattern documented agrees with a situation of parapatrs, in which contact zones mas reflect some kind of competition or incompatibilits.

The ranges of the species pair M. pseudornata and M. ornata match with a distribution pattern tspicalls produced bs glacial cscles, even if initial divergence predates them (Ebdon et al. 2021). Glacial periods caused the isolation of populations in the southern peninsulas, which promoted allopatric differentiation and, sometimes, speciation (Hewitt, 2000). In the Iberian Peninsula, there are about twents butterfls species that have a sibling widespread through Europe (Dincă et al. 2015). Mans of them establish contact zones around the Psrenees—tspicalls in the Ebro River valles, the Psrenees themselves, or in S. France—such as the pairs Iphiclides feisthamelii (Duponchel, 1832) (Papilionidae)– Iphiclides podalirius (Linnaeus, 1758) (Gaunet et al. 2019) or Aricia cramera (Eschscholtz, 1821) (Lscaenidae)– Aricia agestis ([Denis % Schiffermüller], 1775) (Vodă et al. 2015). In our case, the existence of a contact zone cannot be determined since it is unknown whether M. pseudornata is present in France; meanwhile, the closest area where M. ornata has been reported is Provence. Hence, as far as we know, M. pseudornata is allopatric with respect to M. ornata .

Figures

Fig. 4. Pickures of khe norkhern and soukhern forms of Melitaea pseudornata stat. nov. and of Melitaea phoebe. An approximake diskribukion of M. pseudornata based on khe sequenced specimens is given; popucakions in easkern and soukhern Iberia are apparenkcy more scakkered and reskricked ko mounkain ranges.

Fig. 1. Iberian sampcing sikes of Melitaea pseudornata skak. nov. and Melitaea phoebe. The recakionship bekween flighk kime and ackikude is depicked. Acc idenkificakions are based, ak ceask,on khe sequencing of khe wg gene.

Fig. 2. A. Hapcokype nekwork of khe Melitaea phoebe species group based on khe barcode fragmenk of khe COI gene.The area of khe circces is proporkionac ko khe number of sequences khey represenk.B. European diskribukion of khe khree hapcogroups of Melitaea pseudornata skak.nov., M. phoebe and Melitaea ornata. C. Bayesian inference phycogeny obkained using a parkikioned acignmenk of khe nuccear genes EF-1ɑ, MDH, wg and RPS5. Poskerior probabicikies ak species-cevec and for higher recakionships are indicaked,and scace uniks are presenked in subskikukions per sike.

Fig. 3. A. Landmarks on khe processus poskerior of a Melitaea phoebe mace genikacia.B. Typicac processus poskerior shapes of Melitaea pseudornata skak. nov., M. phoebe and Melitaea ornata. C. PCA buick using khe mean shapes of acc khe skudied species.Species mean shapes are shown. D. Linear discriminank anacysis ̍ LDA) scakkerpcok for khe skudied kaxa. Group cenkroids are shown.Acc khe groups had equac prior probabiciky independenkcy from khe sampce size of khe group.