How weather and time influence pollinator activity: Implications for pollination services and agricultural management

Insect pollinators are key to the maintenance of ecosystems and the production of crops needed for human nutrition. This ecosystem service is in jeopardy, however, as pollinators contend with a host of environmental and anthropogenic stressors, of which, climate change is already having an effect. In this thesis I investigate the effects of variable weather conditions on a diversity of pollinating insects to ascertain how contemporary conditions influence pollinator activity as a first step in beginning to understand the impacts of a changing global climate. Furthermore, I explore the diurnal patterns of pollinators to a crop commonly sprayed by pesticide in weather conditions that are invariable and ideal for pollinator activity as a means of scrutinizing current pesticide application recommendations. I collected data by observing pollinator activity, abundance, and behaviour at pollinator nests and two commonly grown crops
- apple and oilseed rape - in a range of weather conditions characteristic of Ireland. I found that a diversity of pollinators varied in their responses to weather and time of day between the nest and on different crops, suggesting that pollinators compensate for the lack of others in certain conditions, and that this should be accounted for when surveying pollinators, assessing their contributions to crops, and implementing management and conservation policy.
These findings represent the first studies of pollinator activity in relation to weather and time of day performed in Ireland but are generally applicable to regions across the world. As a diversity of pollinating insects are differentially affected by abiotic factors, surveying protocol, policy recommendations, and management strategies should account for this. A more comprehensive understanding of the influence of environmental factors on pollinators in the contemporary environment has current implications and lays the groundwork for preparedness in future, variable conditions.