Subspecies limits and hidden Wolbachia diversity in Actinote pellenea butterflies

Abstract

Actinote pellenea is the most widespread species within the genus Actinote (Lepidoptera: Nymphalidae: Heliconiinae: Acraeini). The species has several generations per year (multivoltine) and is also the most diversified, with 18 formally recognized subspecies, most of them morphologically distinct and geographically segregated. In the present study we investigated lineage limits of 12 subspecies of A. pellenea using sequences of one mitochondrial (COI) and one nuclear gene (EF-1 α) to test if nominal geographic lineages are recovered as genetically differentiated. We also surveyed for the presence of Wolbachia in all field-collected individuals of A. pellenea and characterized these bacteria using sequences of wsp and gatB. The analysis of the COI alignment failed to recover all subspecies as monophyletic and only the clade composed for A. pellenea diaguita from Tucumán, Argentina and A. pellenea pellenea from the coastal Atlantic Forest in the states of São Paulo and Bahia, Brazil, was differentiated as a separate lineage. We found a Wolbachia-infection frequency of 68%, in both males and females, and we propose that the presence of these endosymbionts may explain why the mitochondrial gene COI failed to delimit the subspecies of A. pellenea as monophyletic groups. We showed for the first time that these butterflies have an intermediate prevalence of Wolbachia infection. However, several aspects of this infection are still unknown and we concluded the present study with several open questions relative to the interaction between Wolbachia and A. pellenea butterflies.

Key words:

• cytoplasmic incompatibility
• endosymbionts
• mitochondrial variability
• sex ratio
• subspecies

Acknowledgements

We thank several people who helped with suggestions throughout the development of this study: Horacio Montenegro, Aline Sartori Guidolin, Fernando L. Cônsoli and Ronaldo Francini. We are in debt with Dr. Michael Turelli for his kind help reading the first version of our manuscript and with Dr Keith Willmott for sending us several sequences of Ecuadorian subspecies. The authors thank Espaço da Escrita – Pró-Reitoria de Pesquisa, UNICAMP – for the language service provided. This project is registered under SISGEN #A0E7804.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplementary material for this article can be accessed here: https://doi.org/10.1080/14772000.2021.1965669.

Associate Editor: Andrew Brower

Additional information

Funding

This work was supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo under Grant numbers 2012/16266-7 (KLSB); 2015/24663-4 (LMM); 2011/50225-3; 2012/50260-6 and 2013/50297-0 (AVLF); 2018/19171-3 (PEG) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) under Grant number 303834/2015-3 (AVLF).