Population dynamics in greenhouse experiments of aphids and their predators

The data was collected to determine the role of habitat use and non-trophic predator-predator interactions on food-web dynamics. We developed four dynamic food-web models - with vs without habitat use and non-trophic predator interactions - and fit the models to the data. We used mesocosm experiments in the greenhouse, combining all combinations of 0, 1 or 2 predator species with 1 or 2 prey species (33 combinations in total, each with 6 replicates). aphid_counts (1734R × 6C) and pred_counts (180R × 8C): Aphid populations were counted on days 2, 4, 6 and 8, while predator populations were counted on day 8. Aphid populations in treatments with no predator were also counted on day 0, and some treatments with Coccinella septempunctata were counted on day 1 and 3 as well. Initial predator populations were 10 Pardosa, 2 C. septempunctata, 20 O. majusculus, or 20 Bembidion. Where the treatment only contained one predator, these numbers were doubled (i.e. 4 C. septempunctata). 150 aphids were added to each mesocosm on day -2 (i.e. two days before predators were added). This was either 150 of one aphid species or 75 of each aphid species. body_masses_raw (44R x 5C): This data set contains body mass measurements for each species in our experiment. Some species were weighed multiple at a time because of their small size. The columns contain name of the species measured ("Species"), mass of the measured individual(s) in grams ("Mass (g)"), the number of individuals that were weighed together ("Number of individuals"), the per capita mass of those weighed in that group ("Per capita Mass (mg)"), and the average per capita mass for the species, in mg ("Avg species per capita mass (mg)"). aphid_hab_use_by_replicate ( 97R x 5C) and pred_hab_use_by_replicate (985R x 5C): This dataset contains the habitat use of each aphid and predator species. The cage was divided into four areas - walls (and roof), ground, barley, and beans and we recorded the number of individuals located in each area. If an individual moved during counting it was assigned half to each habitat it was in. Aphid habitat use was recorded on days 2 and 6 of the 8 day experiment, while predators were recorded every day (or multiple times a day for Coccinella septempunctata, because we had so few individuals.