The neonicotinoid insecticide imidacloprid disrupts bumblebee foraging rhythms and sleep. Tasman et al.
Neonicotinoids have been implicated in the large declines observed in insects such as bumblebees, an important group of pollinators. Neonicotinoids are agonists of nicotinic acetylcholine receptors that are found throughout the insect central nervous system and are the main mediators of synaptic neurotransmission. These receptors are important for the function of the insect central clock and circadian rhythms. The clock allows pollinators to coincide their activity with the availability of floral resources and favourable flight temperatures, as well as impacting learning, navigation and communication. Here we show that exposure to the field relevant concentration of 10 µg/L imidacloprid caused a reduction in bumblebee foraging activity, locomotion and foraging rhythmicity. Foragers showed an increase in daytime sleep and an increase in the proportion of activity occurring at night. This could reduce foraging and pollination opportunities, reducing the ability of the colony to grow and reproduce, endangering bee populations and crop yields. Tasman et al Figure 1 contains the activity counts for each individual forager for 5 days of LD (collected using the LAM), in 30 minute bins. Each .txt file is for a single bee, first line shows the run name, followed by the monitor number and then the channel number, e.g. 2015CtM022C08. Here run name is 2015Ct, monitor is number 22 and channel is number 8. This is followed by the date on which the run started. The second line shows the number of bins, the third line shows the length of these bins in minutes and the 4th line shows the time of the first bin, e.g. 09:00. The activity count for each bin is then listed. The file contains the data for colonies 1-3, which were combined for analysis of activity levels and circadian rhythms. Each folder contains a text file detailing which individual received which treatment, e.g. control, IM 1 ug/L or IM 10 ug/L. Tasman et al Figure 2 contains the same type of data as in Figure 1 but for 5 days of DD. Tasman et al Figure 3 contains the same type of data as in Figure 1, for 5 days of LD in both 1 min and 30 mins bins, which was used for sleep analysis. Tasman et al Figure 4 contains excel spreadsheets of the readout for the RFID reader, for the 5 days of LD. There is a folder for each of the three runs, within which there are folders for each day of the run and a spreadsheet for each 30 min bin within that day. These spreadsheets show each read from the RFID reader, listing (from left to right) the date and time of the read, the reader number and the ID of the bee being read. Consecutive reads less than 1 min apart from the same bee were counted as one activity bout. Days start at 9am except Day 1 which starts at 10am. There is a text file showing the colony number and treatment for each reader in each run. This was analysed for foraging activity and rhythmicity. Tasman et al Figure 5 shows the same type of data as in Figure 4 but for 5 days of DD.
Steps to reproduce
Full methodology can be found in the associated paper.