Experimental queen removal stimulates caste flexibility of females in Neotropical social wasps (Vespidae Polistinae Epiponini)

Abstract

Caste plasticity is an essential trait in social insects, and it facilitates the allocation of individuals in different tasks according to population demands in the colony (e.g. workers can become queens upon loss or death of their “original queen”). The process of caste determination can take place in immature stages (preimaginal) or through adult stages (imaginal). Neotropical social wasp tribe Epiponini has both types of caste determination process and is thus a fascinating group to study caste plasticity. We performed queen removal tests in five Epiponini species with preimaginal and imaginal caste determination to better understand caste plasticity and queen selection processes. Queen absence stimulates the establishment of new reproductive females in Chartergellus and Metapolybia (imaginal), while females in Protopolybia (preimaginal) attempt to lay eggs even in the presence of their “original queen”. Contrary to what has been hypothesized, we found that age is not a predictive factor in the female’s potential to become a queen. Caste flexibility seems to be a crucial trait which aids Epiponini tropical colonies to survive, as it allows the colony to replace lost workers and queens promptly until a new generation of wasps can emerge.

Highlights

Epiponini wasps presented caste flexibility since workers of different ages could replace queens in the case of they lost.

KEY WORDS:

• social wasps
• caste
• determination
• queen lost
• plasticity

Acknowledgments

We thank Sidnei Mateus for his help in finding the nest in Pedregulho, Brazil; the staff and park rangers of Refugio de Vida Silvestre Golfito for their assistance; Fabiana Fragoso and Sergio Jansen González for the field assistance. Sergio Jansen González kindly reviewed the early versions of this manuscript. We thank Susan Casement for the professional English editing of the manuscript.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

AUTHOR CONTRIBUTION

The study conception and design were performed by L. Chavarría-Pizarro and F.B. Noll. Material preparation and data collection were performed by L. Chavarría-Pizarro, and analyses were performed by L. Chavarría-Pizarro and F.B. Noll. The first draft of the manuscript was written by L. Chavarría-Pizarro and T. Chavarría-Pizarro, and all the authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Additional information

Funding

This work was supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) under grants number 09/07526-2, 11/06058-5, 19/09215-6, and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) under grant number 42199520181.