aaad20d5-e647-4938-9cbf-ea8dedfcab83 https://ipt.gbif.pl/resource?r=myrmica_ab_2025 Michał Kochanowski University of Warsaw PhD student https://orcid.org/0000-0003-4687-5104 Igor Siedlecki University of Warsaw PhD student 0000-0002-0927-9760 Magdalena Witek Museum and Institute of Zoology associate professor 0000-0002-6172-8981 Piotr Ślipiński Museum and Institute of Zoology researcher 0000-0002-7336-4134 Michał Kochanowski University of Warsaw PhD student https://orcid.org/0000-0003-4687-5104 2026-02-12 eng The dataset consists of occurrences of Myrmica scabrinodis nests, which were collected in May 2022 to study ants' task switching and immune response in the context of fungal ectoparasite infection. Fungal parasite - Rickia wasmannii occurrences have presence/absence data. Occurrence GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type_2015-07-10.xml Specimen GBIF Dataset Subtype Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_subtype.xml This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License. Myrmica scabrinodis nests were sampled on wet meadow in Ruczaj, Kraków (Poland). 19.863 19.863 50.027 50.027 2022-05-01 2022-05-31 The dataset consists of the ant host (Myrmica scabrinodis) and fungal parasite (Rickia wasmannii). kingdom Fungi phylum Arthropoda order Hymenoptera phylum Ascomycota class Insecta kingdom Metazoa order Laboulbeniales class Laboulbeniomycetes family Laboulbeniaceae family Formicidae unkown Michał Kochanowski University of Warsaw PhD student

Żwirki i Wigury 101 Warsaw mazowieckie 02-089 PL

mj.kochanowski@uw.edu.pl https://orcid.org/0000-0003-4687-5104 - nest sampling, - infection assessment, - individuals counting The study site was visited once, and 20 colonies of Myrmica scabrinodies were collected; 10 were infected with Rickia wasmannii and 10 were uninfected. Collected ants were transported to the laboratory in plastic bags. In the lab, ants were sorted and counted, and the presence and intensity of infection were measured. Ants were used for behavioural and physiological experiments. Myrmica scabrinodis nests are located in the grass tussock. The whole tussock was dug with a shovel and transported to the laboratory in plastic bags. In the lab, the artificial nests were established, and infection was confirmed with the stereoscopic microscope. This research is part of the project No. 2022/45/P/NZ8/04018 co-funded by the National Science Centre and the European Union Framework Programme for Research and Innovation Horizon 2020 under the Marie Skłodowska-Curie grant agreement No. 945339. 2025-09-29T12:12:53.032+00:00 dataset Kochanowski M, Siedlecki I, Witek M, Ślipiński P (2026). Myrmica scabrinodis and its ectoparasite Rickia wasmannii (Ruczaj, Kraków, Poland 2022). Version 1.6. University of Warsaw. Occurrence dataset. https://ipt.gbif.pl/resource?r=myrmica_ab_2025&v=1.6 Michał Kochanowski, Anna Dubiec, Aleksander Juszczak, Igor Siedlecki, Piotr Ślipiński, Marta Wrzosek, Enikő Csata, Magdalena Witek, Chronic fungal infection accelerates age polyethism in ants without altering immune response, Animal Behaviour, Volume 232, 2026, 123426, ISSN 0003-3472, https://doi.org/10.1016/j.anbehav.2025.123426. (https://www.sciencedirect.com/science/article/pii/S0003347225003537) Abstract: Foraging is a critical activity for many animals, where individuals face many environmental pressures. Among these, parasite infection is one of the most negative threats, especially in social insects, where parasites can be shared among nestmates inside the nest and can affect colony functioning by altering the division of labour within a colony. In the ant Myrmica scabrinodis, the ectoparasite fungus Rickia wasmannii infects the majority of workers in the colony and is linked to reduced lifespan, enhanced immune responses and altered behaviour. Given that task allocation in M. scabrinodis is age dependent, we tested whether R. wasmannii infection accelerates the transition to foraging due to the ants’ shortened life expectancy. Our results confirmed that colonies with high infection intensity exhibited an earlier onset of foraging behaviour. Additionally, immune response, measured through phenoloxidase activity, was more strongly influenced by worker age than task switching or infection status, with older workers exhibiting higher immune activity. This suggests that while infection accelerates task switching, it does not directly impact immune function. Our findings highlight how chronic fungal infection can disrupt the division of labour in social insect colonies. Keywords: ant; ectoparasite; fungal parasitism; division of labour; insect immunity; insect–fungi interaction; Myrmica scabrinodis; phenoloxidase system; Rickia wasmannii; task switch aaad20d5-e647-4938-9cbf-ea8dedfcab83/v1.6.xml