Citizen science can expand our knowledge of biodiversity and enhance conservation programs by adding species records and associated data. This is the case for bees—the main group of pollinators—with millions of observations on iNaturalist.
Here we ask if spontaneous observations made by citizen scientists on this platform provide a good picture of bee diversity in terms of taxonomic coverage (i.e., proportion of different subfamilies, tribes, genera and species), identification acuity (i.e., correct identification and at what taxonomic level) and taxonomic diversity. For this purpose, we compare iNaturalist observations with a dataset from a structured local survey for Curitiba, a city of 2 million inhabitants in southern Brazil.
The search on iNaturalist resulted in 496 bee observations of 52 species, a richness similar to the most urbanised sampling site from the local survey. Highly eusocial and large bees are, proportionally, more frequently observed by citizens than sampled by professionals. Three citizen observers were responsible for more than 50% of the observations in iNaturalist. About 45% of species were correctly identified and this number increased up to 85% after our validation.
We perceive that the spontaneous, non‐structured, observations on iNaturalist bring a biased representation of the bee fauna when compared to the structured local survey. However, the platform shows a great potential to monitor large bodied and eusocial bees, including rare and non‐native species; thus, it may be valuable for bee surveying, monitoring and conservation.