Exploring relationships between time of day and pollinator activity in the context of pesticide use - data

Pesticide exposure can be harmful to insect pollinators and the ecosystem services they provide. As pesticide guidelines warn against applying such products when pollinators are active, it is important to determine how pollinator activity changes with the time of day and when the most appropriate time is to spray these chemicals. We walked transects from sunrise to sunset in oilseed rape (Brassica napus L.) fields in Ireland to capture the abundance of honeybees, bumblebees, solitary bees, and hoverflies across daylight hours. We also recorded the activity of representative species from the three bee groups at their nests across similar time periods to compare with field observations. Peak pollinator abundance was in the mid-afternoon with fewer individuals in the early morning and late evening for all groups. At the nest, we observed patterns of activity that broadly reflected field abundance but indicated that bees are active earlier and later than those observed on the crop. However,..., Pollinator abundance on oilseed rape
We observed three fields of mass-flowering spring-sown oilseed rape (canola; Brassica napus L.) in Co. Carlow, Ireland.
We visited each field six times, twice from 0600-1100, twice from 1100-1600, and twice from 1600-2200. Visits began when oilseed rape reached Growth Stage 6 (flowering) and was conducted in the best weather possible (i.e., dry, clear skies, still, warm) to replicate the recommended conditions for pesticide application which coincide with optimal conditions for pollinator abundance. All observations took place from 15 June to 07 July 2021.
On each visit, we walked three 15-minute transects (with 20 minutes in between) in two-hour blocks. Transects were walked at a slow, steady pace along field tramlines. Tramlines nearest the sides of the fields were designated ‘edge’ and the tramlines past 20 meters into the fields were designated ‘centre;’ composition of a pollinator assemblage can differ between the ‘centre’ and ‘edge’ of fields..., , # Exploring relationships between time of day and pollinator activity in the context of pesticide use - data

## (1) Oilseed rape abundance and weather data

transect - refers to the transect number

site - the field number

location - where in the field observations were made (center or edge)

bumblebee - # of bumblebees observed without pollen load

butterfly - # of butterflies observed

honeybee - # of honeybees observed without pollen load

solitary - # of solitary bees observed without pollen load

bumblebee_pollen - # of bumblebees observed with pollen load

honeybee_pollen - # of honeybees observed with pollen load

solitary_pollen - # of solitary bees observed with pollen load

datetimestart - the date (dd-mm-yy) and time (hh:mm) format an observation began

datetimeend - the date (dd-mm-yy) and time (hh:mm) format an observation ended

meantemp - the average temperature (°C) recorded by the weather station during the observation period

meanrh - the average relative humidity (...