R-code and data from: Contrasting effects of amino acid types on foraging behaviour, colony growth, and worker mortality in red ants and carpenter ants
Description
This data set is a supplement to an article titled: “Contrasting effects of amino acid types on foraging behaviour, colony growth, and worker mortality in red ants and carpenter ants”. We investigated foraging responses of ants to essential proteogenic amino acids (amino acids which cannot be synthesized by the host animal) compared to non-essential amino acids and their associated effects on colony growth in ants. Our full description of the methodology, results, and their interpretation can be found in the publication. Abstract from article: "Foraging ants collect amino acids and proteins for developing larvae in their colony. Both essential amino acids (EAAs; some considered toxic to ants) and non-essential amino acids (non-EAAs) are important building blocks of proteins but EAAs cannot be synthesized by animals and must be obtained from their diet. Whether ants specifically forage for EAAs, and how EAAs affect ant colony growth, has rarely been investigated. Using red ants, Myrmica rubra, and western carpenter ants, Camponotus modoc, as model species, we tested the hypotheses that (1) M. rubra and C. modoc colonies with brood preferentially forage for EAAs rather than non-EAAs; (2) M. rubra colonies provisioned with EAAs, instead of non-EAAs, have greater brood production and colony growth; and (3) M. rubra workers feeding on sucrose and EAAs die sooner than workers feeding on sucrose and non-EAAs (which are considered less toxic). In laboratory choice experiments, colonies of M. rubra and C. modoc preferentially foraged for EAAs rather than non-EAAs. Colonies of M. rubra that consumed both EAAs and non-EAAs, produced more larvae, but not more workers and queens, than colonies that consumed only EAAs or non-EAAs. In a mortality experiment, isolated M. rubra workers that consumed sucrose and EAAs died sooner than workers that consumed sucrose and non-EAAs, possibly because they could not feed EAAs to larvae. Our results indicate that EAAs on their own, while critically important, are insufficient for ant colony growth. However, sucrose and EAAs as key macro-nutrients should be offered in highly appealing baits for control of pest ants." We have uploaded our data and scripts as an R studio project. Code used to wrangle data, analyze data and generate plots can be accessed in the project folder by opening the project file. The project contains: ---Data Data files of laboratory experiments to assess ant consumption, colony growth, and mortality to amino acid formulations. ---Outputs Plots and csv files generated from data analysis. ---Scripts Scripts of R code used to wrangle data, conduct analyses, and generate outputs.
Files
Steps to reproduce
The full description of the methodology can be found in "Effects of micro- and macro-nutrients on short-term, and season-long, foraging responses by select species of ants". Here we describe them in brief, primarily in relation to how the data were collected and used. Data were analyzed in R and R studio. To measure consumption, we bioassayed the feeding response of ant colonies to essential or non-essential amino acids. We presented colonies with choices of aqueous amino acid solutions simultaneously in eppendorf tube feeders and recorded the mass loss after several hours of feeding. We also recorded the mass loss due to evaporation in identical tubes not accessible to the ants. We weighed tubes before and after the experiment to obtain their mass loss. We subtracted the mass loss in evaporation controls from the mass loss in feeding tubes to determine the consumption of the ants. Each data sheet has columns (names may vary by data sheet) for: replicate ("rep"), name of ant colony ("nickname", "MN"), nest identification number ("nest", "col"), position of the tube in the bioassay (randomized to account for tube position; "pos"), the experimental treatments ("trmt", "trt"), initial weight for feeding tubes ("wt.i", "wi"), final weight for feeding tubes ("wt.f", "wf"), initial weight for evaporation controls ("wc.i", "wi.evap"), final weight for evaporation controls ("wc.f", "wf.evap"). To track colony growth we fed ants a complete synthetic diet or diets lacking essential or non-essential amino acids. We froze ant colonies after 16 weeks and counted the number of eggs, larvae, pupae, workers, and queens. Data sheets have similar column names as described with some new columns for: number of workers ("work"), queens ("queen"), alate queens ("Qwing"), eggs ("eggs"), larvae ("larvae"), pupae ("pupa"). To track worker mortality, we fed worker ants either sucrose alone, sucrose plus essential, or sucrose plus non-essential amino acids. We tracked worker mortality over time. Data sheet column names are similar to above with new names for: cumulative count day ("count_day"), number of alive ("alive") or dead ("dead") workers, and number of alive ("alive_adj") or dead ("dead_adj") workers adjusted for workers that had died by day 0 (the start of the experiment) and thus were not exposed to the experimental treatments.