Identification of potential invasive alien species in Spain through horizon scanning.

Invasive alien species have widespread impacts on native biodiversity and ecosystem services. Since the number of introductions worldwide is continuously rising, it is essential to prevent the entry, establishment and spread of new alien species through a systematic examination of future potential threats. Applying a three-step horizon scanning consensus method, we evaluated non-established alien species that could potentially arrive, establish and cause major ecological impact in Spain within the next 10 years. Overall, we identified 47 species with a very high risk (e.g. Oreochromis niloticus, Popillia japonica, Hemidactylus frenatus, Crassula helmsii or Halophila stipulacea), 61 with high risk, 93 with moderate risk, and 732 species with low risk. Many of the species categorized as very high or high risk to Spanish biodiversity are either already present in Europe and neighbouring countries or have a long invasive history elsewhere. This study provides an updated list of potential invasive alien species useful for prioritizing efforts and resources against their introduction. Compared to previous horizon scanning exercises in Spain, the current study screens potential invaders from a wider range of terrestrial, freshwater, and marine organisms, and can serve as a basis for more comprehensive risk analyses to improve management and increase the efficiency of the early warning and rapid response framework for invasive alien species. We also stress the usefulness of measuring agreement and consistency as two different properties of the reliability of expert scores, in order to more easily elaborate consensus ranked lists of potential invasive alien species.

Sublethal doses of glyphosate modulates mitochondria and oxidative stress in honeybees by direct feeding.

Honeybees are essential for the ecosystem maintenance and for plant production in agriculture. Glyphosate is a broad-spectrum systemic herbicide widely used in crops to control weeds and could affect honeybees' health in sublethal doses. Our aim was to study how sublethal doses of glyphosate affects to oxidative stress and mitochondrial homeostasis in honeybees. We exposed honeybees to glyphosate at 5 and 10 mg·l-1 for 2 and 10 h for the gene expression analysis by reverse transcription polymerase chain reaction and for 48 and 72 h for the antioxidant enzymes activity and lipid peroxidation determination. We observed a general increase in antioxidant- and mitochondrial-related genes expression in honeybees after 2 h of exposition to glyphosate, as well as a rise in catalase and superoxide dismutase enzymatic activity after 48 h and an increment in lipid peroxidation adducts generation after 72 h. These results suggest a direct effect of glyphosate on honeybees' health, with an insufficient response of the antioxidant system to the generated oxidative stress, resulting in an increase in lipid peroxidation and, therefore, oxidative damage. Altogether, results obtained in this work demonstrate that sublethal treatments of glyphosate could directly affect honeybee individuals under laboratory conditions. Therefore, it is necessary to investigate alternatives to glyphosate to determine if they are less harmful to non-target organisms.

Automated detection of the yellow-legged hornet (Vespa velutina) using an optical sensor with machine learning.

BACKGROUND: The yellow-legged hornet (Vespa velutina) is native to Southeast Asia and is an invasive alien species of concern in many countries. More effective management of populations of V. velutina could be achieved through more widespread and intensive monitoring in the field, however current methods are labor intensive and costly. To address this issue, we have assessed the performance of an optical sensor combined with a machine learning model to classify V. velutina and native wasps/hornets and bees. Our aim is to use the results of the present work as a step towards the development of a monitoring solution for V. velutina in the field. RESULTS: We recorded a total 935 flights from three bee species: Apis mellifera, Bombus terrestris and Osmia bicornis; and four wasp/hornet species: Polistes dominula, Vespula germanica, Vespa crabro and V. velutina. The machine learning model achieved an average accuracy for species classification of 80.1 ± 13.9% and 74.5 ± 7.0% for V. velutina. V. crabro had the highest level of misclassification, confused mainly with V. velutina and P. dominula. These results were obtained using a 14-value peak and valley feature derived from the wingbeat power spectral density. CONCLUSION: This study demonstrates that the wingbeat recordings from a flying insect sensor can be used with machine learning methods to differentiate V. velutina from six other Hymenoptera species in the laboratory and this knowledge could be used to help develop a tool for use in integrated invasive alien species management programs. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Pollen diet mediates how pesticide exposure impacts brain gene expression in nest-founding bumble bee queens.

A primary goal in biology is to understand the effects of multiple, interacting environmental stressors on organisms. Wild and domesticated bees are exposed to a wide variety of interacting biotic and abiotic stressors, with widespread declines in floral resources and agrochemical exposure being two of the most important. In this study, we used examinations of brain gene expression to explore the sublethal consequences of neonicotinoid pesticide exposure and pollen diet composition in nest-founding bumble bee queens. We demonstrate for the first time that pollen diet composition can influence the strength of bumble bee queen responses to pesticide exposure at the molecular level. Specifically, one pollen mixture in our study appeared to buffer bumble bee queens entirely against the effects of pesticide exposure, with respect to brain gene expression. Additionally, we detected unique effects of pollen diet and sustained (versus more temporary) pesticide exposure on queen gene expression. Our findings support the hypothesis that nutritional status can help buffer animals against the harmful effects of other stressors, including pesticides, and highlight the importance of using molecular approaches to explore sublethal consequences of stressors.

First records of Xylosandrus compactus (Coleoptera: Curculionidae, Scolytinae) in the Iberian Peninsula: an expanding alien species?

Xylosandrus compactus (Eichhoff) (Col.: Curculionidae, Scolytinae) is an ambrosia beetle species native to subtropical Eastern Asia, with great concern due to its high invasive ability. This species has invaded 54 countries worldwide, including 4 European countries (Italy, France, Greece, and Spain); it was detected in Mallorca (Balearic Islands, Spain) in October 2019. In the present work, X. compactus is recorded for the first time in the Iberian Peninsula (Girona province, NE Spain); specimens were collected in Banyoles (August 2020, attacking twigs of Laurus nobilis and Liquidambar styraciflua) and Platja d'Aro (October 2020, attacking twigs of L. nobilis). Up-to-date information is presented about its geographical distribution, host plants, biology, symptoms, associate damages, and the possible origin of this species in Europe.

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

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.

First record of the black twig borer, Xylosandrus compactus (Coleoptera: Curculionidae, Scolytinae) in Spain.

We present the first record for Spain of the black twig borer, Xylosandrus compactus, an ambrosia beetle of Asian origin, collected from an infested carob tree located in Calvià (Majorca, Balearic Islands, Spain). X. compactus is included in the EPPO Alert List, and it has been recently reported causing damages in a Mediterranean maquis ecosystem in Italy and Southern France. Here, we discuss about the first steps of management of this Invasive Alien species (IAS), the eradication plan and the hypothesis of the path of introduction in this Western Mediterranean island.

Diversity of compounds in Vespa spp. venom and the epidemiology of its sting: a global appraisal.

Poisonous animals imply a risk to human life, because their venom is a complex mixture of low molecular weight components, peptides and proteins. Hornets use the venom for self-defence, to repel intruders and to capture prey, but they can cause poisoning and allergic reactions to people. In particular, they seem to be a health problem in the countries where they are native due to their sting, which in the most severe cases can lead to severe or fatal systemic anaphylaxis. But this situation is being an emerging problem for new countries and continents because hornet incursions are increasing in the global change scenario, such as in Europe and America. Furthermore, 55 detailed cases of hornet sting were found in 27 papers during the current review where 36.4% died due to, mainly, a multi-organ failure, where renal failure and liver dysfunction were the most common complications. Moreover, the great taxonomic, ecological diversity, geographical distribution and the wide spectrum of pathophysiological symptoms of hornets have been the focus of new research. Considering this, the present systematic review summarizes the current knowledge about the components of Vespa venom and the epidemiology of its sting to serve as reference for the new research focused on the development of techniques for diagnosis, new drugs and treatments of its sting.

Effects of neonicotinoid insecticide exposure and monofloral diet on nest-founding bumblebee queens.

Bumblebees are among the world's most important groups of pollinating insects in natural and agricultural ecosystems. Each spring, queen bumblebees emerge from overwintering and initiate new nests, which ultimately give rise to workers and new reproductives later in the season. Nest initiation and survival are thus key drivers of both bumblebee pollination services and population dynamics. We performed the first laboratory experiment with the model bumblebee species Bombus impatiens that explores how early nesting success is impacted by the effects of temporary or more sustained exposure to sublethal levels of a neonicotinoid-type insecticide (imidacloprid at 5 ppb in nectar) and by reliance on a monofloral pollen diet, two factors that have been previously implicated in bumblebee decline. We found that queens exhibited increased mortality and dramatically reduced activity levels when exposed to imidacloprid, as well as delayed nest initiation and lower brood numbers in the nest, but partially recovered from these effects when they only received early, temporary exposure. The effects of pollen diet on individual queen- and colony-level responses were overshadowed by effects of the insecticide, although a monofloral pollen diet alone was sufficient to negatively impact brood production. These findings speak to the sensitivity of queen bumblebees during the nest initiation phase of the colony cycle, with implications for how queens and their young nests are uniquely impacted by exposure to threats such as pesticide exposure and foraging habitat unsuitability.