All That Glitters Is Not Gold: The Other Insects That Fall into the Asian Yellow-Legged Hornet Vespa velutina 'Specific' Traps.

Omar Sánchez,Andrés Arias

doi:10.3390/biology10050448

Abstract

Simple SummaryThe recent spreading of the invasive Asian hornet (Vespa velutina) to the Iberian Peninsula has led to the application of management measures to control and mitigate its impact on receiving environments. Among the most used control methods are capture traps, which use a sugary attractant to catch the invasive wasps. However, although the used V. velutina traps are presumably specific, they do not only attract V. velutina specimens, but also a large number of non-target species that are also captured. In the present work, the species of insects that unintentionally fall into the capture traps of V. velutina have been specifically identified, as well as their implications for ecosystem and for human activities. A total of 74 non-target taxa of insects were caught by the V. velutina trapping in northern Spain. Most of them were flies, mosquitoes, wasps and moths, being all highly important groups from the biological, ecological and economical points of view. Surprisingly, the most abundant trapped species was the invasive fly, Drosophila suzukii that represented the 36.07% of the total catches. Furthermore, we reported the first record of ectoparasitic mites of the genus Varroa on V. velutina, constituting a newly recorded symbiotic association.The introduction of invasive species is considered one of the major threats to the biodiversity conservation worldwide. In recent years, an Asian invasive species of wasp has set off alarms in Europe and elsewhere in the world, Vespa velutina. The Asian wasp was accidentally introduced in France around 2004 and shortly thereafter it was able to colonise practically all of Europe, including the Iberian Peninsula. The ecological and economic implications of V. velutina invasion and its high colonisation ability have triggered widespread trapping campaigns, usually supported by beekeepers and local governments, with the aim of diminishing its population and its negative impacts. Among the most used control methods are the capture traps, which use a sugary attractant to catch the invasive wasps. However, the species-specific selectivity and efficiency of these traps has been little studied. In this paper, we have analysed the specific identity of the unintentionally trapped insect species from northern Spain (covering one-year period), as well as we have assessed the provided ecosystem services by them. A total of 74 non-target taxa of insects were caught by the V. velutina studied traps, most of them correspond to the orders Diptera, Hymenoptera and Lepidoptera, the dipterans being the most abundant group. Surprisingly, the most abundant trapped species was the invasive fly, Drosophila suzukii that represented the 36.07% of the total catches. Furthermore, we reported the first record of ectoparasitic mites of the genus Varroa on V. velutina, constituting a newly recorded symbiotic association. Hopefully, the provided information helps to develop new protocols and management tools to control this invasive species in the Iberian Peninsula and other temperate areas of western Europe and the Mediterranean basin.

Highlights

Ongoing human activities, such as agricultural intensification and associated land use changes, habitat destruction and fragmentation, global warming and the spreading of invasive species are causing extensive shifts in native biodiversity worldwide [1,2,3,4,5,6,7,8,9,10]
This study aims as well to assess the functional roles of the trapped insects in the ecosystem and their status, in order to achieve a better understanding of the real effects of V. velutina traps in the ecosystem
For the study of the diversity of insects unintentionally captured by V. velutina traps, we analysed eight monitoring traps located in a plot with a majority plantation of apple trees located in a rural area of Loredo, Asturias, northern Spain (43◦24 N–6◦44 W, 310 m altitude) (Figure 1)

Summary

Introduction

Ongoing human activities, such as agricultural intensification and associated land use changes, habitat destruction and fragmentation, global warming and the spreading of invasive species are causing extensive shifts in native biodiversity worldwide [1,2,3,4,5,6,7,8,9,10]. An invasive species of wasp—Vespa velutina Lepeletier, 1836—has set off alarms in Europe and elsewhere in the world [1,2,3,4,5,6,7]. This famous species, commonly known as yellow-legged wasp or Asian wasp, is native to eastern Asia and belongs to the family Vespidae. Its rapid dispersal has been explained by the fact that V. velutina has not enough autochthonous direct competitors or predators; the local inexhaustible food sources; its high reproduction rates, and the European climate conditions that favour its proliferation and spread into new areas [3,4]

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