Biology subjects

Plante, N.

Publications and source records attributed to Plante, N..

5 recordsLinked to original sources

bioRxiv2026

Genome-resolved metagenomics reveals conserved, flexible and emerging symbioses across global leafhoppers

BackgroundLeafhoppers are among the most important insect vectors of plant pathogens worldwide and depend on microbial symbionts to exploit nutrient-poor phloem diets. However, most studies of leafhopper-associated microbiota have focused on a limited number of taxa or marker-gene surveys, leaving the genomic diversity, ecological organization, and functional potential of these microbial communities poorly understood. Here, we generated the Global Leafhopper Microbiome Catalog by integrating genome-resolved metagenomics from 171 leafhopper species across 11 subfamilies and 13 countries, including the first microbiomes characterized from Arctic leafhoppers. ResultsDe novo assembly and genome reconstruction generated 337 high-quality non-redundant microbial genomes and 18.6 million non-redundant genes, substantially expanding the known microbial diversity associated with Cicadellidae, including several previously undescribed bacterial lineages. Comparative analyses revealed a recurrent modular microbiome architecture composed of: (i) a conserved core of obligate nutritional symbionts, dominated by Candidatus Karelsulcia and Candidatus Nasuia; (ii) a heterogeneous layer of secondary symbionts, including Wolbachia, Arsenophonus, Rickettsia, and Diplorickettsia; and (iii) a dynamic pool of environmentally acquired bacteria. While obligate symbionts remained highly conserved across divergent hosts, secondary and environmental taxa varied substantially among species and regions, suggesting repeated acquisition shaped by ecological filtering rather than host phylogeny alone. Comparative analyses between the specialist corn leafhopper Dalbulus maidis and the more polyphagous aster leafhopper Macrosteles quadrilineatus further showed that closely related vectors can maintain conserved ancestral symbionts while harboring markedly distinct accessory microbiomes. Arctic populations contained unique microbial assemblages enriched in functions associated with cold tolerance, oxidative stress, and reproductive manipulation. In addition, we identified numerous plant-associated bacteria, including phytoplasmas, spiroplasmas, Pantoea, and Erwinia, alongside taxa with predicted nutritional and plant growth-promoting functions. ConclusionsOur findings reveal that leafhopper microbiomes are structured through the interaction of ancient obligate symbioses and flexible environmentally responsive microbial layers. This work establishes a genome-resolved framework for understanding microbiome evolution in insect vectors and highlights the potential role of microbial community structure in host adaptation, pathogen ecology, and sustainable pest management.

microbiology↗

bioRxiv2025

Diverse strains of aster yellows phytoplasma are associated with the potato leafhopper (Empoasca fabae) in Eastern Canada

Phytoplasmas are cell wall-less bacteria that are transmitted by phloem-feeding insects. In Canada, insect vectors of this pathogen are leafhoppers (Hemiptera: Cicadellidae), and they can contribute to significant economic losses. As climate change alters the composition and movement of insect communities, migratory species such as the potato leafhopper (Empoasca fabae, Harris 1841), one of the most abundant leafhoppers in Quebec, may play an emerging role in phytoplasma diseases. Although E. fabae is not currently confirmed to act as a vector, its frequent presence and abundance in fields, along with its potential to acquire phytoplasmas, deserve further investigation. In this study, we tested DNA from E. fabae collected in strawberry fields for the presence of Candidatus Phytoplasma using PCR, as well as inbred colonies for their ability to transmit this pathogen. The amplicons amplified from positive samples were cloned and sequenced to identify phytoplasma groups and subgroups. Our findings confirmed the presence of multiple Aster Yellows (16SrI-related) phytoplasma strains in E. fabae, based on phylogenetic analysis, restriction fragment length polymorphism (RFLP) profiling, and single-nucleotide polymorphism (SNP) profiles. However, the transmission assays did not show vector competence. We propose that although this leafhopper species hosts multiple, possibly new, phytoplasma subgroups, its capacity to transmit the disease remains limited and likely depends on high population density. Overall, these findings emphasize the importance of monitoring common pests like E. fabae as indicators of phytoplasma diversity in Eastern Canadian agricultural systems.

microbiology↗

bioRxiv2025

Uncovering diversity and climatic drivers of leafhopper-parasitoid dynamics in Canada

As climate change reshapes northern agroecosystems, leafhoppers (Hemiptera: Cicadellidae) are shifting their distributions, with implications for pest outbreaks and crop health. In Eastern Canada, we monitored strawberry farms from 2023 to 2024, collecting over 82,000 leafhoppers from 64 genera. Migratory species, Empoasca fabae and Macrosteles quadrilineatus, dominated captures, with sharp abundance increases above 16{degrees}C and 14{degrees}C, respectively, while local species declined under higher rainfall. A major finding was the first Canadian record of the corn pest Dalbulus maidis, a vector of multiple pathogens, likely introduced through long-distance dispersal. Insecticide applications generally failed to reduce leafhopper numbers, highlighting the limitations of current chemical control. Parasitism rates by Gonatopus wasps (Dryinidae), averaged ~3% but peaked in late summer at over 20%, primarily in M. quadrilineatus. Warmer temperatures and seasonal progression increased both parasitism probability and rates. Genomic analyses revealed at least three Gonatopus lineages, including the first complete mitochondrial genome for the genus from the New World, and confirmed multiple host species. We also recorded the first Canadian occurrence of G. clavipes. Our results demonstrate that parasitoids are active, climate-responsive, and capable of targeting dominant pest species. Together, these findings provide the first ecological and genomic baseline for leafhopper-parasitoid interactions in Canada. They point to the potential of conserving and enhancing native parasitoid populations as a foundation for climate-resilient, pesticide-free pest management strategies.

ecology↗

bioRxiv2025

Seasonal Phenology of Empoasca fabae (Hemiptera: Cicadellidae) in Quebec, Canada

Climate change is reshaping insect population dynamics in North America, notably impacting the migratory pest Empoasca fabae (Harris) (Hemiptera: Cicadellidae). While its phenology is well studied in the United States, knowledge gaps exist regarding its dynamics in Eastern Canada, one of its northernmost migration areas. Our study integrates degree-day models, CLIMEX ecological niche modeling, and field-collected data from Quebec to assess E. fabae seasonal phenology and monthly climatic suitability. Our results indicate that E. fabae completes one to two generations in Quebec, with earlier emergence and higher generational potential in warmer southeastern regions compared to cooler northeastern regions. CLIMEX modeling showed that suitable climatic conditions for E. fabae growth begin in April, peak from May to September, and decline by November. First adult captures occurred from late May to early June, with population peaks in June-July and a decrease by September. Observed adult peaks occurred earlier than predicted by degree-day models, suggesting that additional environmental factors, such as wind patterns and host plant availability, influence early-season population dynamics. This study provides a comprehensive understanding of E. fabae phenology in Quebec and highlights the importance of incorporating climatic and ecological modeling to predict future population trends. Further research on diapause onset, late-season persistence, and migration patterns is needed to refine predictive models and inform pest management strategies in Quebec. Understanding these factors will be essential in mitigating potential economic impacts amid ongoing climate change.

ecology↗

bioRxiv2023

Can leafhoppers help us trace the impact of climate change on agriculture?

SUMMARYClimate change is reshaping agriculture and insect biodiversity worldwide. With rising temperatures, insect species with narrow thermal margins are expected to be pushed beyond their thermal limits, and losses related to herbivory and diseases transmitted by them will be experienced in new regions. Several previous studies have investigated this phenomenon in tropical and temperate regions, locally and globally; however, here, it is proposed that climate changes impact on agriculture can be traced through the study of Nearctic migratory insects, specifically leafhoppers. To test this hypothesis, leafhoppers in strawberry fields located in the province of Quebec, eastern Canada, were evaluated. The strawberry-leafhopper pathosystem offers a unique opportunity because leafhoppers can transmit, among other diseases, strawberry green petal disease (SbGP), which is associated with pathogenic phytoplasmas. Here, we found that in the last ten years, the number of leafhoppers has been increasing in correspondence with the number of SbGP cases detected in eastern Canada, reporting for the first time ten species new to eastern Canada and two to the country, although the leafhopper diversity has been seriously affected. Our model using more than 34 000 leafhoppers showed that their abundance is influenced by temperature, a factor that we found also influences the microbiome associated with Macrosteles quadrilineatus, which was one of the most abundant leafhoppers we observed. One of our most striking findings is that none of the insecticides used by strawberry growers can control leafhopper incidence, which could be linked to microbiome changes induced by changing temperatures. We suggest that Nearctic leafhoppers can be used as sentinels to trace the multilayered effects of climate change in agriculture. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=185 SRC="FIGDIR/small/544773v1_ufig1.gif" ALT="Figure 1"> View larger version (77K): org.highwire.dtl.DTLVardef@e984eorg.highwire.dtl.DTLVardef@3146a9org.highwire.dtl.DTLVardef@1160b9aorg.highwire.dtl.DTLVardef@53c39c_HPS_FORMAT_FIGEXP M_FIG C_FIG IN BRIEFThe current climate crisis is reshaping insect biodiversity and abundance, but little is known about the direct effect of this phenomenon on agriculture. In this study, we explored leafhoppers, a group of agriculturally important insect pests and disease vectors, as sentinels of the effect of climate change on agriculture. Our findings indicate that this group of insects can help us to understand the effect of the current climate crisis on insect invasions, diversity, abundance, disease dynamics and insecticide resistance and to take quick action to ensure food security while achieving more sustainable agriculture. HIGHLIGHTSO_LIMigratory leafhoppers benefit from temperature increases C_LIO_LILeafhopper-transmitted diseases have increased in the last decade C_LIO_LINew non-migratory leafhoppers can be found now in Nearctic regions C_LIO_LILeafhopper insecticide resistance could be linked to the insect microbiome C_LI

ecology↗