Six years of controlling the invasive species Vespa velutina in a Mediterranean island: The promising results of an eradication plan

Abstract

BACKGROUND The yellow‐legged hornet, Vespa velutina nigrithorax, is an invasive alien species (IAS) which was accidentally introduced in Europe from Asia. This social insect preys primarily on honeybees but also on other pollinators and insects. Consequently, the establishment of this pest has a negative impact on biodiversity, pollination and economy. There is no clear coordination and uniformed methods for eradication measures between countries. Here we present the first field study of the strategy of eradication of the pest species V. velutina that has been conducted in the westernmost Mediterranean archipelago. RESULTS We investigated the combination of different eradication methods, such as trapping; the use of the citizen science data for detection of presence, the active search of nests and the removal of nests using mechanical methods. The progression of the number of secondary nests found was 1 (2015), 9 (2016) and 20 (2017), with zero during 2018, 2019 and 2020, and just one embryo nest in 2018. More than half of the nests (58%) were detected thanks to citizen science data. The people sent us adult detections, and we started the triangulation method to find the nests. The last hornet found in the traps was in June 2018. CONCLUSION Early detections of the IAS are crucial to minimise their effects, and citizen science may offer an important source of information to determine the presence and distribution of V. velutina. The findings we present here indicate successful management for this globally significant pest and could contribute to advance the ‘science of eradication’. © 2021 Society of Chemical Industry

Tracking the invasive hornet Vespa velutina in complex environments by means of a harmonic radar

“…The length of the tracks recorded by the harmonic radar was compared with the length of the tracks recorded when adopting a customary technique for tracking insects, such as the visual tracking and triangulation of flying directions 20 , 25 . In six of the nine localities where the harmonic radar tracking has been applied (Fig.…”

“…In this study, the visual tracking technique has not been implemented systematically for nest detection, therefore the two approaches are compared only by evaluating the recorded length of the tracks. The effectiveness in locating nests, the required time and the associated costs are discussed in the framework of previous studies for tracking V. velutina , taking into account advantages and limits of the different techniques 20 , 22 , 25 .…”

“…The results from the control strategy established in the Balearic Islands 25 allow delineating some hypothesis concerning the time for locating nests for the visual tracking technique, notwithstanding different environmental characteristics of the study areas may act as confounders. In their invasive scenario of Majorca, the authors were able to detect and remove 30 nests of V. velutina in the years 2015–2017 by visual tracking and triangulation of flying directions; this activity required a mean of 19.2 ± 18.9 working days per nest (min = 0 days, max = 63 days).…”

Ensemble of Small Models As a Tool For Alien Invasive Species Management Planning: Evaluation of Vespa Velutina (Hymenoptera: Vespidae) Under Mediterranean Island Conditions

“…Together with the local authorities, an intensive protocol to detect and remove nests was implemented, as described in Leza et al (2021). In 2015, only one nest was found in the northwest of the island.…”

“…During 2016, nine additional nests were detected and removed, and in 2017 the number of reported nests increased to twenty. Since then no more secondary nests were found (Leza et al 2021), being the rst territory where V. velutina has been o cially eradicated (CAIB 2019).…”