This dataset contains data from a greenhouse experiment described in the paper: Njue, M., Muturi, P., Nyaga, J. and Jonsson, M. 2021. Influence of drought on interactions between Rhopalosiphum padi and ground dwelling predators – a mesocosm study. Journal of Applied Entomology.

The experiment investigates the effects of a factorial combination of two factors: simulated drought vs wet conditions, and ground-dwelling predators present or not on the development of aphids in experimental mesocosms 60 cm x 40 cm x 20 cm in size sown with barley. Dry conditions simulated a situation without rain for 21-28 days and wet conditions received rain every second day. Eighty aphids were introduced to each mesocosm 8 days after barley was sown. On the second day after aphid introduction we added two individuals each of the carabid beetles, Pterostichus melanarius and Harpalus rufipes and of the wolf spider Pardosa spp to each cage assigned to the predator treatments. Aphids were then counted on 16 randomly selected tillers at day 14, 18 and 21 after aphid introductions and their position on the tillers was noted.

Main results were that aphids moved below ground during dry conditions, predators reduced aphid numbers, but only during dry conditions, and predators reduced the proportion of aphids below ground in dry conditions. This increased predation effect during dry conditions was, however, compensated for by a corresponding increase in aphid performance on the plants and so the net effect of drought on aphid numbers ended up being neutral. 

The dataset was collected during a greenhouse study at Swedish University of Agricultural Sciences (SLU) and has been processed by a series of linear mixed models (lme function in the nlme package in R 3.4) to produce a MS accepted for publication in Journal of Applied Entomology.

The readme file contains an explanation of each of the variables in the dataset, its measurement units. Information on how the measurements were done can be found in the associated manuscript referenced above.