R-code and data from: Contrasting effects of a lethal liquid bait on reducing counts of foraging Myrmica rubra and Solenopsis invicta ants

This dataset and R-code are a supplement to a submitted article titled: Contrasting effects of a lethal liquid bait on reducing counts of foraging Myrmica rubra and Solenopsis invicta ants

Article abstract: Liquid ant baits show promise for invasive ant management but bait uptake by ants depends on bait characteristics, such as food components, the type and dose of lethal agent, and the bait matrix (e.g., solid, liquid, gel). We recently reported that field deployment of our liquid ant bait [an aqueous solution of sucrose (4.55% w/v), essential amino acids (1% w/v), and the lethal agent boric acid (1%)] reduced counts of foraging workers of the invasive red ant, Myrmica rubra, likely due to colony decline. Here we tested the effect of a modified bait (sucrose content 45.5% and larger bait reservoir) to enhance bait consumption by ants, and to quickly reduce worker counts of M. rubra and of the invasive red imported fire ant, Solenopsis invicta. In two-choice laboratory bioassays, worker ants of M. rubra and Lasius niger (black garden ant) consumed similar proportions of the original ant bait and the modified ant bait, whereas workers of Camponotus modoc (Western carpenter ants) consumed less of the modified bait. In field trials on M. rubra, forager ant counts in the treatment plot – but not the control plot – significantly declined by day 6 post-treatment and then remained low for the duration of the experiment. However, in field trials on S. invicta, forager ant counts were lower in the treatment plot than in the control plot but they did not decline over the course of the experiment, indicating that bait consumption had a limited effect on curtailing forager activity or colony size. The modified ant bait seems to be more suitable for some ant species than others. Whereas the bait was effective in reducing forager counts, and thus likely colony size, of M. rubra, further studies are needed to test the bait’s effectiveness on other invasive pest ants, particularly those that are well-known liquid feeders such as the Argentine ant.

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 in lab feeding trials, and worker counts in field baiting trials.

---Output
Plots and csv files generated from data analysis.

---Script
Scripts of R code used to wrangle data, conduct analyses, and generate outputs.