Biology subjects

Twort, V. G.

Publications and source records attributed to Twort, V. G..

5 recordsLinked to original sources

bioRxiv2026

Pyrophilic smoke flies (Diptera: Platypezidae: Microsaniinae) from prescribed burnings in boreal Finland: occurrence and behaviour of adult flies and first observations of immature stages

Smoke flies (Diptera: Platypezidae: Microsania) are among the most specialized pyrophilic insects, exhibiting a strong and rapid reaction to smoke. Although their attraction to smoke has been known for a century worldwide, their immature stages and breeding habitat remained undiscovered. We hand-netted smoke flies at seven prescribed forest burns in boreal Finland between 2022 and 2024 and took soil samples in 2026. Smoke fly swarming and reproductive behaviour was observed at all burn sites. We obtained smoke flies of five out of the six Finnish species, with Microsania pallipes dominating (94%). Following the behavioural observations at burn sites, we later screened soil samples and found larvae identified as Microsania mtDNA COI barcodes in the burnt soil. We provide a first description of the larva of Microsania straeleni (Microsaniinae). Our discovery of the larval habitat in burnt soil resolved the long-standing knowledge gap on smoke fly breeding sites. The morphological characteristics of the immature stages will help elucidate the phylogenetic placement of the Microsaniinae within the Platypezoidea lineage.

zoology↗

bioRxiv2023

Signals of positive selection in Palearctic bat species coexisting with a fungal pathogen

Traits that directly influence the survival of an organism are suspect to positive selection. Disease can act as a driving force in shaping the genetic makeup across populations, even species, if the impacts are influencing a particularly sensitive part of their life cycles. White-nose syndrome is a fungal disease that affects bats during hibernation. The mycosis has caused massive population declines of susceptible species in North America, whereas in Eurasia, where the fungal pathogen has coevolved with its hosts for an extended period of time, bats appear to tolerate infection. Here, we adopted both whole-genome sequencing approaches and a literature search to compile a set of 300 genes from which to investigate for signals of positive selection in genomes of 11 Eurasian bats at the codon-level. Our results indicate significant positive selection in 38 genes, many of which have a marked role in responses to infection. Our findings suggest the fungal disease known as white-nose syndrome may have applied a significant selective pressure on hibernatory Eurasian Myotis-bats in the past, which can partially explain their survival in the presence of the pathogen.

evolutionary biology↗

bioRxiv2023

One Method to Sequence Them All? Comparison between Whole-Genome Sequencing (WGS) and Target Enrichment (TE) of museum specimens from the moth families Epicopeiidae and Sematuridae (Lepidoptera)

There are various possibilities for sequencing highly degraded DNA, such as target enrichment (TE), or whole-genome sequencing (WGS). Here we compare TE and WGS methods using old museum specimens of two families of moths in the superfamily Geometroidea: Epicopeiidae and Sematuridae. Until recently, the relationships of these two families were unclear, as few studies had been done. Recently two studies used the TE approach, either on relatively fresh specimens, or on old museum specimens. Here, we aim to increase the sampling of the families Epicopeiidae and Sematuridae from museum specimens using the WGS method. We show that both sequencing methods give comparable results, but, unsurprisingly, WGS recovers more data. By combining TE and WGS data, we confirm that Sematuridae are sister to Pseudobistonidae+Epicopeiidae. Relationships of genera within the families are well supported. With the costs of WGS decreasing, we suggest that using low-coverage whole genome sequencing is becoming an increasingly viable option in the phylogenomics of insects.

evolutionary biology↗

bioRxiv2021

The unresolved phylogenomic tree of butterflies and moths (Lepidoptera): assessing the potential causes and consequences

The field of molecular phylogenetics is being revolutionised with next-generation sequencing technologies making it possible to sequence large numbers of genomes for non-model organisms ushering us into the era of phylogenomics. The current challenge is no longer how to get enough data, but rather how to analyse the data and how to assess the support for the inferred phylogeny. We focus on one of the largest animal groups on the planet - butterflies and moths (order Lepidoptera). We clearly demonstrate that there are unresolved issues in the inferred phylogenetic relationships of the major lineages, despite several recent phylogenomic studies of the group. We assess the potential causes and consequences of the conflicting phylogenetic hypotheses. With a dataset consisting of 331 protein-coding genes and the alignment length over 290 000 base pairs, including 200 taxa representing 81% of lepidopteran superfamilies, we compare phylogenetic hypotheses inferred from amino acid and nucleotide alignments. The resulting two phylogenies are discordant, especially with respect to the placement of the superfamily Gelechioidea, which is likely due to compositional bias of both the nucleotide and amino acid sequences. With a series of analyses, we dissect our dataset and demonstrate that there is sufficient phylogenetic signal to resolve much of the lepidopteran tree of life. Overall, the results from the nucleotide alignment are more robust to the various perturbations of the data that we carried out. However, the lack of support for much of the backbone within Ditrysia makes the current butterfly and moth tree of life still unresolved. We conclude that taxon sampling remains an issue even in phylogenomic analyses, and recommend that poorly sampled highly diverse groups, such as Gelechioidea in Lepidoptera, should receive extra attention in the future.

evolutionary biology↗

bioRxiv2020

Museomics of a rare taxon: placing Whalleyanidae in the Lepidoptera Tree of Life

Museomics is a valuable tool that utilises the diverse biobanks that are natural history museums. The ability to sequence genomes from old specimens has expanded not only the variety of interesting taxa available to study but also the scope of questions that can be investigated in order to further knowledge about biodiversity. Here we present whole genome sequencing results from the enigmatic genus Whalleyana, as well as the families Callidulidae and Hyblaeidae. Library preparation was carried out on four museum specimens and one existing DNA extract and sequenced with Illumina short reads. De novo assembly resulted in highly fragmented genomes with the N50 ranging from 317 - 2,078 bp. Mining of a manually curated gene set of 332 genes from these draft genomes had an overall gene recovery rate of 64 - 90%. Phylogenetic analysis places Whalleyana as sister to Callidulidae, and Hyblaea as sister to Pyraloidea. Since the former sister-group relationship turns out to be also supported by ten morphological synapomorphies, we propose to formally assign the Whalleyanidae to the superfamily Calliduloidea. These results highlight the usefulness of not only museum specimens, but also existing DNA extracts, for whole genome sequencing and gene mining for phylogenomic studies.

evolutionary biology↗