# Ladybird Beetle Diversity in Natural and Human-Modified Habitats in the San Cristóbal Island, Galapagos, Ecuador

## TL;DR

This study identifies 19 ladybird beetle species on San Cristóbal Island, including new and endemic ones, and highlights the need to protect native species from invasive ones spreading in disturbed habitats.

## Contribution

The study reports nine ladybird beetle species newly recorded for San Cristóbal Island and provides insights into the distribution and vulnerability of endemic species.

## Key findings

- Endemic ladybird beetle species are rare and mainly found in native forests, indicating their vulnerability.
- Non-native species like Cheilomenes sexmaculata are spreading into disturbed and natural habitats, raising conservation concerns.
- Cycloneda sanguinea is the most adaptable and prevalent native ladybird beetle species on the island.

## Abstract

This study explores the diversity of ladybird beetles on San Cristóbal Island, Galápagos Archipelago. We found nineteen species, including four already known and nine new ones reported for the first time on the island. Our research showed that endemic species, unique to the Galápagos, are rare and primarily found in native forests, highlighting their need for protection. The native species Cycloneda sanguinea was the most common and adaptable. Non-native species, like Cheilomenes sexmaculata, were found across all disturbed areas, including urban and agricultural zonas, and may be spreading into natural habitats. This information is crucial for conserving the Galápagos’ delicate ecosystems by emphasising the importance of monitoring and managing native and non-native insect species to preserve local biodiversity and prevent adverse environmental impacts.

This study investigates the species richness and distribution of ladybird beetles (Coccinellidae) across various habitats on San Cristóbal Island in the Galápagos Archipelago, Ecuador. Through extensive field surveys, we catalogued nineteen species, including four previously known species (two endemics, Psyllobora bisigma and Scymnobius scalesius, and two natives, Cycloneda sanguinea and Tenuisvalvae bromelicola). We also identified nine possibly native species reported for the first time in the Galapagos islands in this study or correspond to the first voucher specimens for the island. We collected three previously reported non-native species: Cheilomenes sexmaculata, Novius cardinalis, and Paraneda guticollis. Three species belonging to the genera Stethorus, Calloeneis, and Delphastus remain undetermined, pending further taxonomic analyses. Our findings reveal a rich and complex community with notable differences in species abundance and habitat preference. Endemic species were found to be particularly scarce and restricted mainly to crops undergoing forest regeneration and deciduous forests, emphasising their vulnerability and specialised habitat requirements. The native Cycloneda sanguinea emerged as the most prevalent species, exhibiting broad ecological adaptability. Non-native species, like Cheilomenes sexmaculata, were predominantly found in disturbed habitats, with some showing early signs of spreading into more natural environments, raising concerns about their potential impact on local biodiversity. These findings contribute valuable knowledge to understanding Coccinellidae diversity on San Cristóbal Island and highlight the importance of continued monitoring, particularly in the face of ongoing environmental change and the introduction of non-native species. This study underscores the need for targeted conservation efforts to protect the unique and fragile ecosystems of the Galápagos Archipelago.