A low-cost, computer-controlled robotic flower system for behavioral experiments

Abstract Human observations during behavioral studies are expensive, time-consuming, and error prone. For this reason, automatization of experiments is highly desirable, as it reduces the risk of human errors and workload. The robotic system we developed is simple and cheap to build and handles feeding and data collection automatically. The system was built using mostly off-the-shelf components and has a novel feeding mechanism that uses servos to perform refill operations. We used the robotic system in two separate behavioral studies with bumblebees (Bombus terrestris): The system was used both for training of the bees and for the experimental data collection. The robotic system was reliable, with no flight in our studies failing due to a technical malfunction. The data recorded were easy to apply for further analysis. The software and the hardware design are open source. The development of cheap open-source prototyping platforms during the recent years has opened up many possibilities in designing of experiments. Automatization not only reduces workload, but also potentially allows experimental designs never done before, such as dynamic experiments, where the system responds to, for example, learning of the animal. We present a complete system with hardware and software, and it can be used as such in various experiments requiring feeders and collection of visitation data. Use of the system is not limited to any particular experimental setup or even species

Data from: Low dose of neonicotinoid insecticide reduces foraging motivation of bumblebees

Widespread use of neonicotinoid insecticides, such as imidacloprid, is often associated with diminishing populations of bees; this loss of pollinators presents a concern for food security and may cause unpredictable changes in ecological networks. However, little is known about the potential behavioral mechanisms behind the neonicotinoid-associated pollinator decline. We quantified the effects of low dose (1 ppb) imidacloprid exposure on the foraging behaviour of bumblebees (Bombus terrestris). Individual bumblebees were released into a flight arena containing three patches of robotic flowers whose colour (yellow, orange, blue) indicated whether the flower delivered a reward (sugar solution). Exposure to imidacloprid had no significant effect on measures of bumblebee physical performance (such as flight speed) or learning (identifying rewarding flowers). However, pesticide treated bumblebees had reduced foraging motivation compared with the control bumblebees, as they visited fewer robotic flowers, were slower to start foraging and did not visit all three flower colours as often. Neonicotinoid concentrations of 1 ppb, often reported in plant nectar near agricultural lands, can thus affect the foraging behaviour of bumblebees. Even without a notable impact on flight performance and learning, a reduction in foraging motivation could explain the poor performance of colonies of bumblebees exposed to neonicotinoids

Summary dataset with one value per bumblebee

Summary dataset of bumblebee behaviour exposed to 1 ppb imidacloprid in sugar solution and none in pollen. Rawdata is collected via a robotic flower system (Kuusela & Lämsä 2016) and the data is collapsed into a CSV file allowing easy import to statistical software, such as R

Dataset with the whole foraging sequence (multiple values per bumblebee)

The whole foraging sequence of bumblebees exposed to 1 ppb imidacloprid in sugar solution and none in pollen. Rawdata was collected via a robotic flower system (Kuusela & Lämsä 2016) and was collapsed into a CSV file to allow easy import to statistical software, such as R. The dataset can be used to analyse i.e. difference in learning rates

spectra

Relative spectral reflectance of used colours (maximum reflectance = 1, maximum illumination = 1). nm = wavelenght, hue30=orange, used only in the nest cage, hue35=used both in flight arena and nest cage (quinine in the flight arena, the difficult learning task), hue43=yellow, used both in flight arena and nest cage (sugar solution in the flight arena, the rewarding flower), flightarenablue=used both in flight arena and nest cage (quinine in the flight arena, the easy learning task), nestcageblue= blue, used only in the nest cage, floor=floor reflectance, illumination=illumination spectra, relative values (highest value=1)

Low dose of neonicotinoid insecticide reduces foraging motivation of bumblebees

Abstract Widespread use of neonicotinoid insecticides, such as imidacloprid, is often associated with diminishing populations of bees; this loss of pollinators presents a concern for food security and may cause unpredictable changes in ecological networks. However, little is known about the potential behavioural mechanisms behind the neonicotinoid-associated pollinator decline. We quantified the effects of low-dose (1 ppb) imidacloprid exposure on the foraging behaviour of bumblebees (Bombus terrestris). Individual bumblebees were released into a flight arena containing three patches of robotic flowers whose colour (yellow, orange, blue) indicated whether the flower delivered a reward (sugar solution). Exposure to imidacloprid had no significant effect on measures of bumblebee physical performance (such as flight speed) or learning (identifying rewarding flowers). However, pesticide-treated bumblebees had reduced foraging motivation compared with the control bumblebees, as they visited fewer robotic flowers, were slower to start foraging and did not visit all three flower colours as often. Neonicotinoid concentrations of 1 ppb, often reported in plant nectar near agricultural lands, can thus affect the foraging behaviour of bumblebees. Even without a notable impact on flight performance and learning, a reduction in foraging motivation could explain the poor performance of colonies of bumblebees exposed to neonicotinoids

Supplementary material from “Low dose of neonicotinoid insecticide reduces foraging motivation of bumblebees”

Supplementary information about methods, tables S1 & S2, figures S1-S18