If you’ve ever tried to film insect activity in the field over long periods of time, it is likely that you would have encountered a few unsurmountable technical challenges. Whether you tried using a camera trap, a surveillance or a DSLR camera, you would certainly have had issues with illuminating the scene at night, the autonomy of the device, the infra-red motion sensor’s lack of sensitivity to ectothermic insects (if the device had one) or the ability to film in macro mod. Given of course, that the device did not simply malfunction when exposed to harsh weather conditions.
Researchers from CBI/UCLA and IRD, Vincent Deblauwe and Vincent Droissart, who are interested in the undocumented pollination biology of the West African ebony and rare epiphytic orchids, decided to develop their own DIY camera to fill the technology gap they encountered. The result, called PICT (Plant-insect Interactions Camera Trap), is made up of easy to obtain components: a Raspberry Pi Zero computer, a mini camera, a near-infrared LED to automatically illuminate the scene at night, a USB power bank and a waterproof lunch box in which to enclose everything. The camera can be placed in difficult to reach places like the canopy of a tropical tree, and remotely controlled with a smartphone through Wi-Fi.
Because each unit costs less than $100 USD and can film over several successive days and nights, they were able to record insect visits over many individual plants simultaneously. With the help of collaborators, they deployed PICT in the rainforests of Cameroon. For the first time, they were able to unveil secrets of unknown pollinators of orchid and ebony flowers.
Having tried and tested their camera traps extensively, they are excited about what this technology can offer to advance the study of plant-insect interactions, as it addresses the main limitations – technical and financial- that had till now prevented the use of camera traps for observing little known and little-seen insect behavior.
The paper is available as an unedited proof for the moment. It will be released as open access under CC-BY.
Vincent Droissart, Laura Azandi, Eric Onguene, Marie Savignac, Thomas B. Smith, Vincent Deblauwe. PICT: A low cost, modular, open-source camera trap system to study plant-insect interactions. Methods in Ecology and Evolution. https://doi.org/10.1111/2041-210X.13618
The technical guide and computer code that describes the building and use of PICT to supplement the paper are available here: https://doi.org/10.5281/zenodo.4139839
The Research Institute for Development (Institut de Recherche pour le Développement, IRD) press release is available here: https://www.ird.fr/une-camera-piege-innovante-et-low-cost-pour-etudier-les-interactions-plantes-insectes.