Large-scale DNA barcoding reveals highly distinct insect distribution patterns across Costa Rican ecosystems

Area of Science:

• * Biodiversity research
• * Molecular ecology
• * Conservation science

Background:

• * Insects are vital for global biodiversity but remain understudied.
• * A national inventory is essential for understanding insect diversity and informing conservation strategies.
• * DNA barcoding offers a powerful tool for large-scale biodiversity assessment.

Purpose of the Study:

• * To conduct a national inventory of Costa Rican insects using DNA barcoding.
• * To analyze the ecogeographic structure and spatial distribution of insect communities.
• * To provide a genomic framework for biodiversity monitoring and conservation in tropical regions.

Main Methods:

• * Generated 3.78 million DNA barcodes from 152,891 Barcode Index Numbers (BINs) across 28 localities in Costa Rica (2017-2023).
• * Employed barcode-based community analyses and bootstrapped Jaccard distances to assess ecogeographic structure.
• * Conducted separate analyses for major insect orders (Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera) and key families.

Main Results:

• * Identified seven distinct mainland insect assemblages and one island cluster, shaped by topography and elevation.
• * Revealed strong ecogeographic structuring and extremely high species turnover, with most BINs being region- or locality-exclusive.
• * Demonstrated limited overlap of insect communities across different ecosystems, highlighting unique taxonomic assemblages per life zone.

Conclusions:

• * Large-scale DNA barcoding effectively detected fine-grained spatial structure in insect communities.
• * Each Costa Rican life zone harbors unique insect assemblages, underscoring the need for localized conservation efforts.
• * The study provides a genomic framework for enhanced biodiversity monitoring and conservation in rapidly changing tropical environments.