# Aphids (Hemiptera: Aphididae) in Living Collections of Selected European Botanic Gardens: Diversity, Biosecurity Challenges, and Sentinel Insights

## TL;DR

This paper explores aphid diversity in European botanic gardens and shows how these gardens can serve as early warning systems for invasive aphid species that threaten plant health.

## Contribution

The study introduces botanic gardens as sentinel sites for detecting invasive aphid species and highlights their role in biosecurity.

## Key findings

- More than one hundred aphid species were recorded across five European botanic gardens.
- Several alien aphid species of Oriental and Nearctic origin were detected, including new national records.
- Alien aphids were found in both outdoor and controlled environments, suggesting potential entry points and early intervention opportunities.

## Abstract

Botanic gardens host diverse living plant collections that attract a wide range of insects, including aphids, some of which may become invasive pests. This study documents aphid species recorded in selected European botanic gardens and highlights the role of these institutions as early-warning sites for alien aphids relevant to plant health and biosecurity.

Botanic gardens host diverse living plant collections and are increasingly recognized as sentinel sites for documenting insect biodiversity and detecting biological invasions. Aphids (Hemiptera: Aphididae) are well suited to such monitoring due to their close host associations, rapid population growth, and importance as horticultural pests and virus vectors. Here, we document the aphid fauna recorded in five European botanic gardens—Zabrze (Poland), Meise (Belgium), and the Royal Botanic Gardens in Edinburgh, Benmore, and Logan (UK)—based on surveys conducted in 2022 and 2023. Sampling approaches included short-duration expert bioblitz-style surveys and extended seasonal monitoring. In total, more than one hundred aphid species were recorded across all sites. Observed species lists differed among gardens and survey periods, reflecting variation in sampling timing, intensity, and host plant composition. Several alien aphid species to Europe of Oriental and Nearctic origin were detected, including multiple new national records. Alien taxa were found both in outdoor living collections and in controlled environments such as glasshouses, nurseries, restricted areas, and plant shops, which may function as entry points as well as locations for early intervention. These findings illustrate the value of botanic gardens for documenting aphid diversity and supporting early detection of non-native species relevant to plant health and biosecurity.