Author: Cleo Bertelsmeier

Jelena, Sébastien and Cleo have published a study on thermoregulatory traits and climatic niches in Cataglyphis ants in collaboration with Spanish and French researchers. see Link.

Predictions of future species distributions rest on the assumption that climatic conditions in the current range reflect fundamental niche requirements. Here, we measured heat tolerance, chill coma recovery, body size and phylogenetic relationships in 19 desert specialist ants in the genus Cataglyphis to test if these important determinants of fundamental niches are good predictors of species realized niches. We modelled species climatic niches using 19 bioclimatic variables from WorldClim for recorded occurrence of each species. None of the determinants of the species’ fundamental niche were linked to their realized climatic niche, modelled using species distribution models. However, both heat tolerance and chill coma recovery were highly correlated with body size andall three thermoregulatory traits were phylogenetically constrained, suggesting they reflect fundamental requirements of each species.Thes results challenge the basic assumption of climatic niche modelling, that the realized niche can be used as a proxy for determining fundamental nicherequirements. These findings are particularly concerning for studies that use the species’ current realized niche to predict their responses to climate change.

Bujan, J., Ollier, S., Villalta, I., Devers, S., Cerdà, X., Amor, F., Dahbi, A., Bertelsmeier, C.*, Boulay, R.* (2022) Can thermoregulatory traits and evolutionary history predict climatic niches of thermal specialists? Diversity and Distributions,  http://doi.org/10.1111/ddi.13511, *equal contribution

Congratulations to Aymeric Bonnamour for his first paper in his PhD!!! It was published today in Ecology Letters. https://onlinelibrary.wiley.com/doi/10.1111/ele.13863#

Insect and plant invasions follow two waves of globalisation

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 (~1820–1914, 1960-present), and it remains unclear whether these two waves have influenced invasion dynamics of many species. To test this, we built a statistical model that accounted for temporal variations in sampling effort. We found that insect and plant invasion rates did not continuously increase over the past centuries but greatly fluctuated following the two globalisation waves. Our findings challenge the idea of a continuous acceleration of alien species introductions and highlight the association between temporal variations in trade openness and biological invasion dynamics. More generally, this emphasises the urgency of better understanding the subtleties of socio-economic drivers to improve predictions of future invasions.

 Bridgehead effects distort global flows of alien species

Bertelsmeier, C., & Ollier, S. (2021). Diversity and Distributions, ddi.13388. https://doi.org/10.1111/ddi.13388

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 intercontinental flows between donor and recipient regions misrepresents the introduction history. Here, we show that such bridgehead effects distort our view of global species flows.

https://onlinelibrary.wiley.com/doi/10.1111/ddi.13388

Invasion disharmony in the global biogeography of native and non‐native beetle species

Liebhold, A. M., Turner, R. M., Blake, R. E., Bertelsmeier, C., Brockerhoff, E. G., Nahrung, H. F., Pureswaran, D. S., Roques, A., Seebens, H., & Yamanaka, T. (2021).  Diversity and Distributions, ddi.13381. https://doi.org/10.1111/ddi.13381

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 world to test whether beetle invasions represent a random sample of species or whether some families are more prone to invade than others.

https://onlinelibrary.wiley.com/doi/10.1111/ddi.13381

Thanks to a fruitful collaboration with several international researchers, we have published new research on

“Worldwide border interceptions provide a window into human-mediated global insect movement”

https://europepmc.org/article/med/34255404:

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 directly intercept potentially damaging non-native species to prevent their introduction. Detection of organisms during inspections may also provide crucial information about the species composition and relative arrival rates in invasion pathways that can inform the implementation of other biosecurity practices such as quarantines and surveillance. In most regions, insects are the main taxonomic group encountered during inspections. We gathered insect interception data from nine world regions collected from 1995 – 2019 to compare the composition of species arriving at ports in these regions. Collectively, 8,716 insect species were intercepted in these regions over the last 25 years, with the combined international dataset comprising 1,899,573 interception events, of which 863,972 were identified to species level. Rarefaction analysis indicated that interceptions comprise only a small fraction of species present in invasion pathways. Despite differences in inspection methodologies, as well as differences in the composition of import source regions and imported commodities, we found strong positive correlations in species interception frequencies between regions, particularly within the Hemiptera and Thysanoptera. There were also significant differences in species frequencies among insects intercepted in different regions. Nevertheless, integrating interception data among multiple regions would be valuable for estimating invasion risks for insect species with high likelihoods of introduction as well as for identifying rare but potentially damaging species.