Public Engagement Provides First Insights on Po Plain Ant Communities and Reveals the Ubiquity of the Cryptic Species Tetramorium immigrans (Hymenoptera, Formicidae)

SIMPLE SUMMARY: Public involvement in biodiversity research in the form of Citizen Science is a powerful tool to improve our understanding of the natural world, and it is especially suitable for the study of heavily populated environments. Ants’ ubiquity and diversity, their role as ecological bioindicators, and the fact that most species can easily be sampled makes them ideal candidates for this kind of studies. In the framework of the international School of Ants citizen science project, we joined the “BioBlitz Lombardia” in which citizens are invited to collect biodiversity data on several parks from Lombardy (Po Plain, Italy). As a result, we recorded 30 ant species and obtained a first characterization of the region’s ant assemblages. We studied their patterns of variation in relation with the ecological difference between the studies sites, which ranged from urban to subalpine areas. In addition, we detected the presence of a cryptic species (Tetramorium immigrans) whose distribution and identity were only recently clarified. It likely represents an under-recorded introduced species in the region. Advantages and critical aspects of using CS methodology for the study of biodiversity are discussed in light of our experience. ABSTRACT: Ants are considered a useful model for biodiversity monitoring and several of their characteristics make them promising for citizen science (CS) projects. Involving a wide range of public figures into collecting valuable data on the effect of human impact on ant biodiversity, the School of Ants (SoA) project represents one of the very few attempts to explore the potential of these insects in CS. Through the collaboration with the “BioBlitz Lombardia” project, we tested the SoA protocol on 12 Northern Italy parks, ranging from urban green to subalpine protected sites. As a result, we obtained some of the very first quantitative data characterizing the ants of this region, recording 30 species and highlighting some interesting ecological patterns. These data revealed the ubiquitous presence of the recently taxonomically defined cryptic species Tetramorium immigrans, which appears to be probably introduced in the region. We also discuss advantages and criticisms encountered applying the SoA protocol, originally intended for schools, to new categories of volunteers, from BioBlitz participants to park operators, suggesting best practices based on our experience.