Evidence for Range Expansion and Origins of an Invasive Hornet Vespa bicolor (Hymenoptera, Vespidae) in Taiwan, with Notes on Its Natural Status.

Sheng-Shan Lu,Wen-Chi Yeh,Yi-Jing Lin,Ming-Lun Lu,Junichi Takahashi,Jing-Yi Huang,I-Hsin Sung

doi:10.3390/insects12040320

Abstract

Simple SummaryThe invasive hornet Vespa bicolor Fabricius was first discovered in Taiwan in 2003 and was not confirmed to have been established until 2014. This study was conducted in order to (1) assess the current status of V. bicolor abundance, dispersal, seasonality, and possible impact on honeybee (Apis mellifera Linnaeus) in Taiwan; (2) and to trace the origins of Taiwan’s V. bicolor population. To assess V. bicolor abundance, we used visual surveys, sweep netting, and hornet traps in four known ranges in northern and central Taiwan from 2016 to 2020. Additionally, to understand V. bicolor dispersion, we mapped environmental data using ArcGIS, and to predict future V. bicolor range, we used ecological niche modeling. The results show that V. bicolor has stable populations in three areas in northern and central Taiwan, and mainly preys on Apis mellifera. Our analyses suggest samples from Southeastern China as having the closest relation in DNA sequences with Taiwan’s V. bicolor population. Due to the negative economic and ecological impacts of V. bicolor in Taiwan, our findings shed light on the value of monitoring and controlling its populations, rather than working exclusively towards elimination.The invasive alien species (IAS) Vespa bicolor is the first reported hornet that has established in Taiwan and is concerning as they prey on honeybee Apis mellifera, which leads to colony losses and public concerns. Thus, the aim of this study was to assess the current status of V. bicolor abundance, dispersal, and impact and to trace the origins of Taiwan’s V. bicolor population. Our studies took place in five areas in northern to central Taiwan. We used mtDNA in the phylogenetic analyses. Field survey and ecological niche modeling (ENM) were used to understand the origins and current range of the invasive species. Two main subgroups of V. bicolor in the phylogenetic tree were found, and a clade with short branch lengths in Southeastern China and Taiwan formed a subgroup, which shows that the Taiwan population may have invaded from a single event. Evidence shows that V. bicolor is not a severe pest to honeybees in the study area; however, using ENM, we predict the rapid dispersion of this species to the cooler and hilly mountain areas of Taiwan. The management of V. bicolor should also involve considering it a local pest to reduce loss by beekeepers and public fear in Taiwan. Our findings highlight how the government, beekeepers, and researchers alike should be aware of the implications of V. bicolor’s rapid range expansion in Taiwan, or in other countries.

Highlights

Invasive alien species (IAS) are non-native species that often cause adverse consequences in their new environment [1]
The phylogenetic tree of the COI region near the 50 end showed that all V. bicolor hornets from Beijing and Huangshan, Hong Kong, Nepal, Taiwan, and Vietnam were closely related to form a monophyletic clade (Figure 2A)
Many local populations spread to the northern area of Taoyuan City; we assess that V. bicolor adapts to cooler weather in subtropical areas

Summary

Introduction

Invasive alien species (IAS) are non-native species that often cause adverse consequences in their new environment [1]. IAS should be monitored and controlled to prevent negative impact on agriculture and ecosystem function, as well as social and economic impacts on human beings [2]. The sheer diversity and niche breadth of insects allow them to play a significant role as IAS globally. They are far understudied compared with plants and vertebrates. 70% of the studies were conducted in North America [3]. These findings beg the need for studying IAS in Asia, especially in the North Asian region. Hornets are dominant and increasingly concerning players, as they can (1) be aggressively harmful to humans and other animals [4] and (2) spread due to nesting substrate availability during international trade [5,6]

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