Trophic_Transfer_of_Microplastic_in_Social_Hymenoptera

Relevance, background, gap of knowledge, reduced methods, findigs and interpretation: Anthropogenic pollutants are one facet of global change contributing to insect decline in terrestrial ecosystems. Microplastic (MP), a major particulate pollutant, is already ubiquitously present in terrestrial ecosystems and expected to further accumulate. However, studies on effects of MP on the ecologically important social insects are still scarce. In social insects, negative effects of MP pollution could not only manifest on the individual but also on the colony level due to cooperative brood care. We tested whether MP particles taken up by workers of the Japanese carpenter ant (Camponotus japonicus) and the buff-tailed bumblebee (Bombus terrestris) are transferred to larval stages during brood care. We exposed ant and bumblebee workers to MP-contaminated food and subsequently analysed the digestive systems of workers, larvae, and pupae for the presence of MP particles. Both, ant and bumblebee workers, had ingested MP particles with food. However, while we found numerous MP particles in the digestive system of bumblebee larvae, we found no MP particles in the digestive system of ant larvae. This is likely due to the infrabuccal pocket (IBP), a filtering device for particulate matter only present in the ants, that effectively prevents the transfer of particulate pollutants such as MP within colonies during cooperative brood care. In contrast, in bumblebees the unobstructed transfer of MP from workers to larvae may entail negative effects on larvae or carry-over effects during development. Thus, negative colony-level effects of pollutants on social Hymenoptera may be exacerbated in those species that lack an IBP. The data shows the detection of MP on the body surface or in the body (e.g. digestive system) of the different developmental stages (larva, pupa, worker) of ants (Camponotus japonicus) or bumblebees (Bombus terrestris). The data shows a clear assignment of specimens to the treatment groups [fed with MP, fed with control solutions] and explains their origin (source colonies/microcolonies). Data Gathering: The data was gathered after experimental exposition of the organisms to the respective treatments via dissection or tissue clearing. The MP particles were fluorescence labelled and, therefore, were detected with fluorescence microscopy. Data and code use: The data can be used like any other presece/absence data. All important information on the data per coloumn are given in the headers. All steps of analysis are expained in the R-script.