Data Used for Visualization in 2014
HOW DO DIFFERENCES IN GROWTH BETWEEN TWO WEED SPECIES AFFECT INTERACTIONS
WITH A PLANT-FEEDING INSECT USED IN THEIR BIOCONTROL?
The study plants: Hawkweeds
The study insect: A plant-feeding gall wasp
Entomologist and agricultural research scientist, Dr Rose De Clerck-Floate (Agriculture and Agri-Food Canada, Lethbridge Research Centre), studies the intricacies of insect-plant interactions in order to use insects in the control of weeds. The plants being targeted for “biological control” are destructive pests of native grasslands, that have been introduced to North America from mainly Europe and Asia without the natural enemies that would normally keep them in check in their homelands. Weed biological control aims to reunite the most specific and effective of the insect enemies with their natural hosts. Some of the most specific and intimate of insect-plant interactions are between gall-forming insects and their host plants. Gall insects induce the production of unique plant growths, which protect and nourish developing, immature stages of the insect. The developing insects within the galls, however, also draw nutrients and resources from the plant that would normally go to plant growth and reproduction, thereby potentially curtailing the invasiveness of these plants.
For this exhibition, Rose provided the students with raw data from a greenhouse experiment that explored the interaction between a gall-forming, plant-feeding wasp (Aulacidea subterminalis) and the growing prostrate stems (also called “stolons”) of two host weed species of this biocontrol insect; “mouse ear” and “whiplash” hawkweeds. The experiment was set up to ask the questions:
· Is there a difference in how the two hawkweed species grow and develop as plants age?
· If yes, do species-based differences in growth and development affect plant-gall wasp interactions?
· What do the differences tell us about the potential efficacy of the gall wasp as a biocontrol agent of these weed species?
The experiment took into consideration the effects of both plant species (mouse ear and whiplash hawkweeds) and the stage of plant development at the time of attack by the wasp (“super young”, “young”, “mid”, and “old”). At harvest, the number of galls produced per plant and per stolon type (“main” stolons, which are the first to grow from the centre of young plants, and “lateral” stolons, which arise as branches from the main stolons later in plant development), which gives us an indication of what type of plant growth the gall wasps preferred or were tracking within plants. We also counted the total number of main and lateral stolons, which gave us an indication of; a) whether or not the galls had reduced plant growth, and/or b) whether the plant had responded to the presence of galls through stolon growth.
The students were initially given background information on the experiment, and the plants’ and insect’s biology, but were not told what answers Rose and her collaborating scientist colleague, Dr Rob Laird (University of Lethbridge, Department of Biological Sciences) found during statistical analyses of the data (see graphs). Thus what you will see in this exhibition represents the students’ individualistic artistic expressions of the data, but also their apparent empirical approaches to exploring and understanding the data and its revelations…….a process also generating new perspectives and creative lines of enquiry for the scientists.