The plant-pollinator relationship is a heavily relied upon ecosystem service. For the ecosystem service to work, plants attract pollinators using a number of visual and odour signals. These signals are important for foraging pollinators as they indicate the presence of floral rewards, including pollen and nectar. Varying environmental conditions, such as temperature, humidity and rainfall can cause changes in both floral signals and floral rewards. With ongoing weather pattern shifts due to climate change, metrics such as rainfall are expected to become less predictable. It is important to gauge how these changes may affect plant-pollinator relationships

and its resulting ecosystem services. In this study, I explored how Bombus terrestris bumble bees adjust foraging efforts at tomato plants (Solanum lycopersicum) grown in greenhouses under high, medium/control, and low induced watering conditions. Bumble bees displayed no statistically significant differences in the proportion of time spent foraging at high, medium/control, and low level watered plants, indicating no bias for or against tomatoes in a specific treatment. However, there were marginal longitudinal preferences, where bees showed a tendency to spend a smaller proportion of their foraging bout on flowers in the low watering treatment over time.

I also explored how changes in watering conditions and presence of active pollinators influence tomato fruit yield and seed production. Tomato plants that received high and low watering levels produced fewer flowers than plants that received medium (control) water levels. There were fewer flowers present in enclosures with bees than those without, since bees were active foragers cause flowers to close after successful pollination. Both tomato weight and number were not influenced by watering conditions, but enclosures with bees had significantly more and heavier tomatoes than those without bees. This indicates that bee pollinators increase crop yield, and that watering treatments did not cause any significant differences in crop yield in either bee-pollinated or non-bee pollinated enclosures. This shows that the given watering levels over a short term, during the adult stages of the tomato lifecycle, were not drastic enough to result in noticeable differences in fruit production. Average seed weight and number were significantly lower in plants receiving high water levels in enclosures with bees, compared with all other treatment groups, including enclosures without. This suggests that watering influences seed production independently of pollination. However, the small bee sample size for seed harvest from tomatoes grown without bees may have influenced these results. Further studies would be needed to confirm these findings.

These results imply that watering treatments only influenced some aspects ofthe plants’ health and did not significantly influence foraging behaviour of bumble bee pollinators. Yet, they also underscore the intricate relationship between plants, pollinators and environmental conditions, emphasizing the need for further research. Especially with the increasing unpredictability of weather patterns and pollinator decline, it becomes crucial to understand how these factors influence plant-pollinator interactions.