Replication Data for: Hormonal modulation of brood allocation underlying evolutionary conflicts in the supercolonial ant Tapinoma darioi

This repository contains the datasets and R script for the article "Hormonal modulation of brood allocation underlying evolutionary conflicts in the supercolonial ant Tapinoma darioi", published in the journal Behavioral Ecology and Sociobiology. It contains three datasets, one regarding queen survivorship, one related to methoprene and precocene effect on larvae cannibalization, and one containing data for queen number effect on larvae cannibalization. Additionally, a file containing metadata information for the three datasets is supplemented. Finally, the R script file utilised for statystical analysis in this publication is also present.

In social insects, caste fate is typically determined by larval feeding, but in several species juvenile hormone (JH) also regulates caste development, with elevated JH levels biasing brood towards queens. In some ants, queens influence the caste fate of their offspring by depositing higher JH levels into eggs. We hypothesized that in polygynous societies, individual queens could gain fitness advantages over co-nesting reproductives by increasing JH deposition, thereby producing more sexuals that are reared by workers with low relatedness. To test this, we conducted a bioassay in the supercolonial ant Tapinoma darioi, experimentally altering queens’ circulating JH levels via topical application of methoprene (a JH analogue) and precocene II (a JH synthesis inhibitor), while monitoring brood production. Our results show that workers detect and cull the excessive production of reproductive brood, revealing for the first time the precise moment at which this occurs. These findings support the hypothesis that maternal control of JH deposition into eggs can bias caste fate to the queen’s advantage, particularly in supercolonial species where sexual larvae are often reared by unrelated workers. At the same time, our data indicate that workers are not at a loss in this evolutionary conflict of interests, since they can detect and cannibalize excess queen larvae, likely adjusting the queen/worker ratio towards the colony’s optimum from their own evolutionary perspective. Overall, our study highlights the dynamic interplay between maternal control and worker counter-adaptation in shaping caste determination, providing new insights into the mechanisms and evolutionary conflicts underlying social insect reproduction.