Diversity and relevance of non-sphingid moths as pollinators in the Neotropics

Understanding the pollination mechanisms of "settling moths" (moths from families other than Sphingidae typically perched on corollas while feeding on flowers) in the Neotropics is crucial for assessing their contributions to plant reproduction and ecosystem resilience. Through extensive literature searches on Google Scholar and SCOPUS, this study identified 44 relevant studies from an initial pool of 410. These studies covered 37 ecoregions across over 30 million km², primarily focusing on natural habitats, with Brazil, Argentina, and Mexico as major contributors. The research on Neotropical moth pollination has surged since 2000, with Noctuoidea, Geometridae, and Pyraloidea as the most cited moth groups. Despite the significant progress in documenting moth pollination, our assessment of taxonomic resolution revealed a heavy reliance on field observations, underscoring the need for collaboration with taxonomists to improve species-level identifications and enrich ecological interpretations.

Our network analysis of interactions between 37 plant families and 14 nocturnal moth families or higher taxon groups indicated a matrix fill of approximately 18.7%, with significant nestedness pointing to generalist-specialist dynamics among plant and moth families. Modularity analysis identified distinct clusters of interactions, suggesting that specific plant and moth families engage in compartmentalized relationships shaped by ecological and evolutionary factors. Dominant groups, such as Asteraceae and Fabaceae among plants, and Erebidae and Noctuidae among moths, played central roles within these modules, underscoring their importance in maintaining nocturnal pollination networks.

These findings emphasize the importance of both diverse and dominant pollinator groups in supporting Neotropical pollination dynamics. Our work highlights the need for pollinator-centered studies, the adoption of standardized methodologies, and deeper exploration of exclusive moth pollination to advance understanding of plant reproduction across the Neotropics. Future research should aim to bridge gaps in species-level identification and further investigate the ecological and evolutionary significance of nocturnal pollination across diverse environments.

Methods
Our study focused on phalaenophily, or pollination by “settling moths”, (hereafter referred to as moths), encompassing all Lepidoptera except hawkmoths (Sphingidae) and butterflies (Papilionoidea). To identify relevant studies on pollinating moths, we conducted searches on Google Scholar and SCOPUS using the following combinations of terms (number of results in brackets): (“Settling moths”) and (Neotropic*) [97], (Phalaenophily) and (Neotropic*) [105], (Falenofilia) and (Neotropic*) [110]; and on SCOPUS, we employed the search string “Title, Abstract & Keywords” with the following terms: pollinat* AND (lepidoptera OR moth*) AND (neotrop*) [56], pollinat* AND (lepidoptera OR moths) AND (south AND merica) [38], phalaenophily AND (neotropic*) [1], (“Settling moths”) and (Neotropic*) [2], (Falenofilia) and (Neotropic*) [0], (Noctuidae) and (Neotropic*) and (Pollin*) [1]. We considered studies in any language, including Spanish, Portuguese and English. A study was included in the analysis only if it specifically mentioned the interaction of a moth with a particular plant and, if cited as a “morphospecies”, we ensured that the moth was not a hawkmoth [referred to as “small moths”, “microlepidoptera”, “settling moths” (English), “polilla” (Spanish), “mariposa” (Portuguese)]. We accepted moth identifications as correct without requiring independent verification and updated nomenclature only when necessary.

After conducting searches, all 410 studies retrieved were meticulously reviewed to pinpoint references to moth species involved in flower pollination or visitation. Out of these, only 44 studies met the inclusion criteria and were integrated into our study. We compiled this information into a comprehensive table, detailing various aspects of each study.