Cleo Bertelsmeier

• PhD
• Professor at University of Lausanne

Invasions by nonnative insect species can massively disrupt ecological processes, often leading to serious economic impacts. Previous work has identified propagule pressure as important driver of the trend of increasing numbers of insect invasions worldwide. In the present article, we propose an alternative hypothesis—that insect invasions are bein...

As geographic distance increases, species assemblages become more distinct, defining global biogeographic realms with abrupt biogeographic boundaries. Yet, it remains largely unknown to what extent these realms may change because of human-mediated dispersal of species. Focusing on the distributions of 309 non-native ant species, we show that histor...

Globalisation has facilitated the spread of alien species, and some of them have significant impacts on biodiversity and human societies. It is commonly thought that biological invasions have accelerated continuously over the last centuries, following increasing global trade. However, the world experienced two distinct waves of globalisation (~1820...

Significance The global pet trade may accelerate the spread of invasive species around the world, which threatens native biodiversity and impacts human economy and health. Here, using an extensive metaanalysis, we show that invasive species are strongly overrepresented across mammals, birds, reptiles, amphibians, and fish traded as pets. Even in th...

The rising introduction of invasive species through trade networks threatens biodiversity and ecosystem services. Yet, we have a limited understanding of how transportation networks determine spatiotemporal patterns of range expansion. This knowledge gap may stem from two reasons. First, current analytical models fail to integrate the invader's lif...

Wildlife trade affects a quarter of terrestrial vertebrates(1) and creates novel opportunities for cross-species pathogen transmission(2-4). Yet, its precise role in shaping human-wildlife pathogen exchanges remains unclear. Analysing 40 years of global wildlife trade data, we show that traded mammals are twice as likely to share pathogens with hum...

Globalization has spread thousands of invasive insect species into new world regions, causing severe losses in ecosystem services. Previous work proposed that plant invasions facilitate insect invasions through the creation of niches for non-native herbivores. Despite the impact of insect invasions, a comprehensive understanding is lacking on how i...

Introductions of insect predators and parasitoids for biological control are a key method for pest management. Yet in recent decades, biological control has become more strictly regulated and less frequent. Conversely, the rate of unintentional insect introductions through human activities is rising. While accidental introductions of insect natural...

Aim The Hemiptera is the fifth‐largest insect order but among non‐native insect species is approximately tied with the Coleoptera as the most species‐rich insect order (Hemiptera comprise 20% more species than in world fauna). This over‐representation may result from high propagule pressure or from high species invasiveness. Here, we assess the rea...

Urban areas experience higher temperatures compared to rural areas and as such, are increasingly considered places of acclimatization and adaptation to warming. Small ectotherms, such as insects, whose body temperature rises with habitat temperature, are directly affected by temperature changes. Thus, warming could have a profound effect on insect...

Citizen science is a key resource in overcoming the logistical challenges of monitoring biodiversity. While datasets collected by groups of volunteers typically have biases, recent methodological and technological advances provide approaches for accounting for such biases, particularly in the context of modelling species distributions and diversity...

Aim Invasions of non‐native insects can have substantial impacts on agriculture, forestry, human health and biodiversity with considerable economic and environmental consequences. To understand the causes of these invasions, it is important to quantify the relative influence of principal drivers such as international imports and climatic effects....

Brief introduction: What are microclimates and why are they important? Microclimate science has developed into a global discipline. Microclimate science is increasingly used to understand and mitigate climate and biodiversity shifts. Here, we provide an overview of the current status of microclimate ecology and biogeography in terrestrial ecosystem...

Reviews the conceptual approaches and the most significant advances in our current understanding of insect physiology, genetics, ecology, evolution, and conservation within the ongoing and rapidly developing context of global anthropogenic climate change. Synthesizes the available knowledge concerning the impact of climate change on insect populati...

Climate change is ten times faster now than in the last global warming event, 56 million years ago, with temperature and extreme weather dramatically increasing due to human activity. This rapid changes in climate affect all levels of biodiversity. However, despite their high global biodiversity, only 3 percent of global climate change literature i...

The rising introduction of invasive species through trade networks threatens biodiversity and ecosystem services. Yet, we have a limited understanding of how transportation networks determine patterns of range expansion. This is partly because current analytical models fail to integrate the invader's life-history dynamics with heterogeneity in huma...

The geographical exchange of non-native species can be highly asymmetrical, with some world regions donating or receiving more species than others. Several hypotheses have been proposed to explain such asymmetries, including differences in propagule pressure, source species (invader) pools, environmental features in recipient regions, or biological...

Background Pathogen outbreaks mostly originate from animals, but some species are more likely to trigger epidemics. The giant land snail (Lissachatina fulica) is a widespread invader, a popular exotic pet, and a notorious vector of the rat lungworm, causing eosinophilic meningitis in humans. However, a comprehensive assessment of the risks of disea...

Aim Non‐native species are part of almost every biological community worldwide, yet numbers of species establishments have an uneven global distribution. Asymmetrical exchanges of species between regions are likely influenced by a range of mechanisms, including propagule pressure, native species pools, environmental conditions and biosecurity. Whil...

International trade continues to drive biological invasions. We investigate the drivers of global nonnative ant establishments over the last two centuries using a Cox proportional hazards model. We use country‐level discovery records for 36 of the most widespread nonnative ant species worldwide from 1827 to 2012. We find that climatic similarity co...

Thousands of insect species have been introduced outside of their native ranges, and some of them strongly impact ecosystems and human societies. Because a large fraction of insects feed on or are associated with plants, nonnative plants provide habitat and resources for invading insects, thereby facilitating their establishment. Furthermore, plant...

Globalization has contributed to the spread of thousands of species, yet only a few harmful ones have attracted most attention. New evidence shows that introduced ants are a particularly important group of global invaders that can dominate native insect communities.

The global pet trade is a major risk to biodiversity and humans and has become increasingly globalized, diversified, digitalized, and extremely difficult to control. With billions of internet users posting online daily, social media could be a powerful surveillance tool. But it is unknown how reliably social media can track the global pet trade. We...

The geographical exchange of non-native insects can be highly asymmetrical, with some world regions 'exporting' or 'importing' more species than others. Several hypotheses have been proposed to explain such asymmetries, including differences in propagule pressure, environmental features in recipient regions, or biological traits of invaders. We tes...

Globalization and economic growth are recognized as key drivers of biological invasions. Alien species have become a feature of almost every biological community worldwide, and rates of new introductions continue to rise as the movement of people and goods accelerates. Insects are among the most numerous and problematic alien organisms, and are mai...

Invasive species are over-represented on the exotic pet market. Using ants as a model system, we show that the pet trade not only creates opportunities for invasions, but that it also favors specifically invasive species.

Aim: Lepidoptera is a highly diverse, predominantly herbivorous insect order, with species transported to outside their native range largely facilitated by the global trade of plants and plant-based goods. Analogous to island disharmony, we examine invasion disharmony, where species filtering during invasions increases systematic compositional diff...

Globalization has led to the unintentional movement of thousands of species around the world, necessitating a better understanding of how species are spread by international trade to prevent new invasions. However, to date, the evidence implicating global trade in intercontinental species flows has been mixed. Here, we show that commonly used proxi...

Aim Predictions of future species distributions rest on the assumption that climatic conditions in the current range reflect fundamental niche requirements. So far, it remains unclear to what extent this is true. We tested if three important factors determining fundamental niche—ecophysiology, morphology and evolutionary history—can predict the rea...

Invasive species often displace native species by outcompeting them. Yet, some native species can persist even in heavily invaded areas. The mechanisms mediating this local coexistence are still unclear. Fine-scale microclimatic heterogeneity could promote the local coexistence of native and invasive animal competitors. We tested if native ant spec...

Predictions of future biological invasions often rely on the assumption that introduced species establish only under climatic conditions similar to those in their native range. To date, 135 studies have tested this assumption of 'niche conservatism', yielding contradictory results. Here we revisit this literature, consider the evidence for niche sh...

As part of national biosecurity programs, cargo imports, passenger baggage, and international mail are inspected at ports of entry to verify compliance with phytosanitary regulations and to intercept potentially damaging nonnative species to prevent their introduction. Detection of organisms during inspections may also provide crucial information a...

Aim A major goal of invasion biology is to understand global species flows between donor and recipient regions. Our current view of such flows assumes that species are moved directly from their native to their introduced range. However, if introduced populations serve as bridgehead populations that generate additional introductions, tracing interco...

Aim The concept of “island disharmony” has been widely applied to describe the systematic over- and under-representation of taxa on islands compared to mainland regions. Here, we explore an extension of that concept to biological invasions. We compare biogeographical patterns in native and non-native beetle (Coleoptera) assemblages from around the...

Social insects are among the worst invasive species and a better understanding of their anthropogenic spread is needed. I highlight recent research demonstrating that social insects have been dispersed since the early beginnings of globalized trade and in particular after the Industrial Revolution, following two waves of globalization. Many species...

Globalization is removing dispersal barriers for the establishment of invasive species and enabling their spread to novel climates. New thermal environments in the invaded range will be particularly challenging for ectotherms, as their metabolism directly depends on environmental temperature. However, we know little about the role climatic niche sh...

The globalization of trade and human movement has resulted in the accidental dispersal of thousands of alien species worldwide at an unprecedented scale. Some of these species are considered invasive because of their extensive spatial spread or negative impacts on native biodiversity. Explaining which alien species become invasive is a major challe...

Despite the enormous negative consequences of biological invasions, we have a limited understanding of how spatial demography during invasions creates population patterns observed at different spatial scales. Early stages of invasions, arrival and establishment, are considered distinct from the later stage of spread, but the processes of population...

It is extraordinary to witness the spread of COVID-19 almost in real-time. This tight monitoring of the invasion of a new virus is a situation that most other invasion scientists could only dream of. Especially spatiotemporal spread data of the early phases of an invasion would be extremely useful in order to understand and predict the human-mediat...

Central to the problem of biological invasions, human activities introduce species beyond their native ranges and participate in their subsequent spread. Understanding human-mediated dispersal is therefore crucial for both predicting and preventing invasions. Here, we show that decomposing human-mediated dispersal into three temporal phases: depart...

The resilience of an individual to environmental change depends on its ability to respond adaptively. Phenotypic flexibility, i.e., reversible phenotypic plasticity, is such an adaptive response, which has been predicted to evolve in unpredictable environments. We present data on the environmental predictability for 17 generations of socially flexi...

Impacts of climate change are likely to be marked in areas with steep climatic transitions. Species turnover, spread of invasive species, altered productivity, and modified processes such as fire regimes can all spread rapidly along ecotones, which challenge the current paradigms of ecosystem management. We conducted a literature review at a contin...

Biological invasions are a major threat to biodiversity, agriculture and human health. Invasive populations can be the source of additional new introductions, leading to a self-accelerating process whereby “invasion begets invasion”. This phenomenon, coined “bridgehead effect”, has been proposed to stem from the evolution of higher invasiveness in...

Significance Because of the globalization of trade and travel, worldwide invasion rates are high. A potential driver of the global acceleration of new invasions is the so-called bridgehead effect, in which initial invasive populations serve as the source of additional invasions via secondary introductions. However, the frequency and overall importa...

Criticism has been levelled at climate-change-induced forecasts of species range shifts that do not account explicitly for complex population dynamics. The relative importance of such dynamics under climate change is, however, undetermined because direct tests comparing the performance of demographic models vs. simpler ecological niche models are s...

Many species show intraspecific variation in their social organization (IVSO), which means the composition of their social groups can change between solitary living, pair living, or living in groups. Understanding IVSO is important because it demonstrates species resilience to environmental change and can help us to study ultimate and proximate rea...

Human trade and travel are breaking down biogeographic barriers, resulting in shifts in the geographical distribution of organ- isms, yet it remains largely unknown whether different alien species generally follow similar spatiotemporal colonization patterns and how such patterns are driven by trends in global trade. Here, we analyse the global dis...

Identifying the factors that promote the success of biological invasions is a key pursuit in ecology. To date, the link between animal personality and invasiveness has rarely been studied. Here, we examined in the laboratory how Argentine ant populations from the species’ native and introduced ranges differed in a suite of behaviours related to spe...

Termites are ubiquitous insects in tropical, subtropical, and warm temperate regions and play an important role in ecosystems. Several termite species are also significant economic pests, mainly in urban areas where they attack human-made structures, but also in natural forest habitats. Worldwide, approximately 28 termite species are considered inv...

Biological invasions have been unambiguously shown to be one of the major global causes of biodiversity loss. Despite the magnitude of this threat and recent scientific advances, this field remains a regular target of criticism - from outright deniers of the threat to scientists questioning the utility of the discipline. This unique situation, comb...

The advent of simple and affordable tools for molecular identification of novel insect invaders and assessment of population diversity has changed the face of invasion biology in recent years. The widespread application of these tools has brought with it an emerging understanding that patterns in biogeography, introduction history and subsequent mo...

Climate change affects the rate of insect invasions as well as the abundance, distribution and impacts of such invasions on a global scale. Among the principal analytical approaches to predicting and understanding future impacts of biological invasions are Species Distribution Models (SDMs), typically in the form of correlative Ecological Niche Mod...

Among invasive species, ants are a particularly prominent group with enormous impacts on native biodiversity and ecosystem functioning. Globalization and ongoing climate change are likely to increase the rate of ant invasions in the future, leading to simultaneous introductions of several highly invasive species within the same area. Here, we inves...

Climate change and biological invasions are among the greatest threats to biodiversity, and their impacts might increase by the end of this century. Among invasive species, ants are a prominent group due to their negative impacts on native species, ecosystem processes, human and animal health, agro-ecosystems, and the economy. Ants are expected to...

Ants are among the most problematic invasive species. They displace numerous native species, alter ecosystem processes, and can have negative impacts on agriculture and human health. In part, their success might stem from a departure from the discovery–dominance trade-off that can promote coexistence in native ant communities, that is, invasive ant...

Ants figure prominently among the worst invasive species because of their enormous ecological and economic impacts. However, it remains to be investigated which species would be behaviourally dominant when confronted with another invasive ant species, should two species be introduced in the same area. In the future, many regions might have suitable...

Documenting the range size and range boundaries of species, and understanding the factors determining changes in these spatial components, is crucial given current rates of anthropogenic climate change and habitat loss. Here, we document the establishment of the acraeine butterfly, Acraea terpsicore , in South‐East Asia (Indonesian islands south of...

Many ants are among the most globally significant invasive species. They have caused the local decline and extinction of a variety of taxa ranging from plants to mam- mals. They disturb ecosystem processes, decrease agricultural production, damage infra- structure and can be a health hazard for humans. Overall, economic costs caused by invasive ant...

Following its introduction from Asia to the USA, the Asian needle ant (Pachycondyla chinensis) is rapidly spreading into a wide range of habitats with great negative ecological affects. In addition, the species is a concern for human health because of its powerful, sometimes deadly, sting. Here, we assessed the potential of P. chinensis to spread f...

As climatically suitable range projections become increasingly used to assess distributions of species, we recommend systematic assessments of the quality of habitat in addition to the classical binary classification of habitat. We devised a method to assess occurrence probability, captured by a climatic suitability index, through which we could de...

Climate change and invasive species are two of the most serious threats of biodiversity. A general concern is that these threats interact, and that a globally warming climate could favour invasive species. In this study we investigate the invasive potential of one of the ''100 of the world's worst invasive species'', the big-headed ant Pheidole meg...

Biological invasions are among the greatest threats to global biodiversity, but in contrast to most other global threats, they suffer from specific communication issues. Our paper presents the first new addition to the widely cited IUCN list of ''100 of the world's worst invasive species'', a list created a decade ago in response to these communica...

We developed a database of 24 major ecological char-acteristics of ants – "Ant Profiler" – which includes information on species morphology, colony dynamics, behaviour, habitat, nest-ing sites, diet, species interactions and distribution. Our database is a publically available research tool to study the ecology of ants and relies on the contributio...

Ants are among the worst invasive species, and can have tremendous negative impacts on native biodiversity, agriculture, estates, property and human health. Invasive ants are extremely difficult to control, and thus early detection is essential to prevent ant invasions, in particular through surveillance efforts at ports of entry. This paper assess...

Ecology Letters (2012) 15 : 365–377 Abstract Many studies in recent years have investigated the effects of climate change on the future of biodiversity. In this review, we first examine the different possible effects of climate change that can operate at individual, population, species, community, ecosystem and biome scales, notably showing that s...

There are more than 12.000 described species of ants living on every landmass on Earth but Antarctica. They are ubiquitous and dominant members of most ecosystems. A small subset of these species has become invasive following human-mediated transportation and have been shown to displace numerous native species, alter communities and disrupt crucial...