Rafter, M. A. | Search bioRxiv

bioRxiv2025

PhyloControl: a phylogeny visualisation platform for risk analysis in weed biological control

O_LIPhylogenetic distance is a key measure used to develop species lists for host specificity tests that delimit the fundamental and realised host range of candidate weed biocontrol agents to meet the assumptions of the centrifugal phylogenetic method. Plant pathogens and insects, even those with broad host ranges, exhibit some degree of phylogenetic conservatism in their host plant associations. Thorough host-specificity testing is crucial to minimise the risk of off-target damage by biocontrol agents to native and economically important plant species. To facilitate this, host test lists need to be developed from an understanding of evolutionary relationships, usually visualised as a phylogenetic tree generated from genetic data, together with plant functional traits and geospatial information. Currently, the process of obtaining a host test list is not standardised, and the manual steps are time-consuming and challenging. C_LIO_LIWe introduce a user-friendly visualisation tool called PhyloControl to aid researchers in their decision-making during biocontrol risk analysis. PhyloControl integrates taxonomic data, molecular data, spatial data, and plant traits in an intuitive interactive interface, empowering biocontrol practitioners to summarise, visualise and analyse data efficiently. C_LIO_LIComprehensively sampled phylogenetic trees are often unavailable, and older published phylogenies often lack branch resolution and support, which increases uncertainty. PhyloControl includes a workflow implemented through Quarto notebooks in R that allows users to download publicly available DNA sequences and perform phylogenetic analyses. The modular workflow also incorporates species distribution modelling to predict the current and potential extent of target weed species. C_LIO_LIPhyloControl will streamline the development of biocontrol host tests lists to support risk analysis and decision making in classical weed biological control. C_LI

plant biology↗

bioRxiv2022

Unique neural coding of crucial versus irrelevant plant odors in a hawkmoth

The sense of smell is pivotal for nocturnal moths to locate feeding and oviposition sites. However, these crucial resources are often rare and their bouquets are intermingled with volatiles emanating from surrounding background plants. Here we asked if the olfactory system of female hawkmoths, Manduca sexta, could differentiate between crucial and background cues. To answer this question, we collected nocturnal headspaces of numerous plants in a natural habitat of M. sexta. We analyzed the chemical composition of these headspaces, and used them as stimuli in physiological experiments at the antenna and in the brain. The intense odors of floral nectar sources evoked strong responses in virgin and mated female moths, most likely enabling the localization of profitable flowers at a distance. Bouquets of larval host plants and most background plants, in contrast, were subtle, thus potentially complicating host identification. However, despite being subtle, antennal responses and brain activation patterns evoked by the smell of larval host plants were clearly different from those evoked by other plants. Interestingly, this difference was even more pronounced in the antennal lobe of mated females, revealing a status-dependent tuning of their olfactory system towards oviposition sites. Our study suggests that female moths possess unique neural coding strategies to find not only conspicuous floral cues but also inconspicuous bouquets of larval host plants within a complex olfactory landscape.

neuroscience↗