Solitary and semisocial behaviour in the Corynura group: new findings in a clade sister to all other Augochlorini bees (Hymenoptera: Halictidae)

ABSTRACT

The great diversity of social organisation present in the tribe Augochlorini makes these bees prime candidates from which to study the evolution of social behaviour. The Corynura group, sister to all other augochlorines, is comprised by three southern South American genera: Callistochlora, Corynura and Halictillus. The nest architecture and social behaviour of Ca. aureoviridis, Co. ampliata, Co. bruchiana, Co. nahuelita, H. amplilobus and H. reticulatus were studied in Argentina. Conclusive evidence of solitary and semisocial behaviour were found in a group where only communal behaviour had been confirmed. Two species presented socially polymorphic populations. Previous studies are reviewed and all data analysed considering species’ flying periods. The possibility of eusocial behaviour is briefly discussed considering environmental factors. Since some of the species visit crops, these results are useful to develop techniques to manage native bees for pollination.

KEYWORDS:

• sweat bees
• social behaviour
• nest architecture
• Argentina
• Chile

Acknowledgements

I thank an anonymous reviewer for comments on the manuscript. I thank Arturo Roig Alsina and Laurence Packer for their comments on an earlier version of the manuscript, Anne-Isabelle Gravel and Luis Compagnucci for their help in the field, Esteban González Zugasti and Juan Farina for their support, and Priscila Hanisch for the identification of the ants. Special thanks to the Administración de Parques Nacionales, Dirección General de Control de los Recursos Faunísticos (Province of Neuquén), and Dirección de Fauna Silvestre of the Secretaría de Ambiente y Desarrollo Sustentable de la Nación, for the permits granted. The study was possible thanks to a doctoral scholarship from CONICET to RGV. Field trips were supported by the Fondo iBOL Argentina – CONICET, and the Agencia Nacional de Promoción Científica y Técnológica under Grant PICT2007-1238.

Availability of data and material

All data generated or analysed during this study are included in this published article and its Online Supplementary Material files (ESM_1.pdf, ESM_2.pdf).

Geolocation information

Sites studied are detailed in Table 1, and in the Supplementary Geolocation Information file (SGI.xlsx).

Disclosure statement

No potential conflict of interest was reported by the author.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00222933.2022.2134833

Additional information

Funding

This work was supported by the Agencia Nacional de Promoción Científica y Técnológica [PICT2007-1238]; and by Fondo iBOL Argentina – CONICET.