Stephen R. Sharpe

A bstract: We extend the relativistic field theoretic finite-volume formalism to Nππ scattering states at maximal isospin, I = 5 / 2. As in previous work using the relativistic field theory approach, we work to all orders in a generic low-energy effective theory, and determine the quantization condition that relates finite-volume energies to intermediate K matrices, and the integral equations connecting the latter to the physical scattering amplitudes. We discuss the parametrization of the K matrices, and explain in detail the new features that arise in implementing the quantization condition due to the spin of the nucleon in combination with the use of non-degenerate particles. As a concrete example, we provide a sample numerical application including the ∆ resonance in the Nπ subchannel. The extension to the I = 3 / 2 and 1 / 2 channels is more involved, due to mixing with Nπ states, and we do not provide a complete formalism for these cases. We explain why Nπ states cannot be included by treating the nucleon as a pole in p -wave Nπ scattering, an approach that has been successful in studying DD ^* scattering using the three-particle DDπ formalism. We additionally provide results for all isospins under the assumption of no two-to-three mixing, thereby laying the groundwork for a follow-up paper in which all Nππ → Nπ systems are fully treated. Finally, we study the singularities in Nππ amplitudes arising from Nπππ intermediate states, and find that our subthreshold cutoff functions must be modified to avoid such singularities.

BACKGROUND: Pest fruit flies commonly carry diverse RNA viruses with unknown host effects that may affect pest management strategies. We investigated effects of horizontally transmitted cripavirus and vertically transmitted iflavirus in Queensland fruit fly that also carried orbivirus, toti‐like virus and xinmovirus as persistent covert infections. RESULTS: Individuals persistently infected with these five viruses had slower egg‐to‐pupa development, lower emergence and lower adult survival under stress than individuals without cripavirus and iflavirus, but persistently infected with the other three viruses. Pupal weight and flight ability did not differ. Cripavirus and iflavirus loads were stable, even under stress, except for the iflavirus load which was higher in flies that died late and lower in flies under stress after cold treatment. Injection into flies of a suspension containing all five viruses caused high mortality within 20 days irrespective of a persistent iflavirus infection. This resulted in an increased iflavirus load 2 days after injection, whereas the load of the other four viruses did not change, suggesting that iflavirus may have caused the mortality. By contrast, feeding the mixed virus suspension did not reduce survival. Although iflavirus was detected immediately after ingestion, its load decreased over 14 days as expected for a maternally transmitted virus. The load of the other four viruses remained unchanged. CONCLUSION: RNA viruses can affect control strategies involving mass‐reared flies such as the sterile insect technique in different ways. Persistent virus infections may moderately influence fly fitness, whereas newly acquired infections may result in increased virus replication and fly mortality. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Graphical A metatranscriptomics study of a dominant bluetongue virus vector, Culicoides brevitarsis from Australia, identified 10 complete/near-complete viral genomes including 7 novel species.

Insect‐specific viruses (ISVs) can affect insect health and fitness, but can also interact with other insect‐associated microorganisms. Despite this, ISVs are often studied in isolation from each other, in laboratory populations. Consequently, their diversity, prevalence and associations with other viruses in field populations are less known, yet these parameters are important to understanding virus epidemiology. To help address this knowledge gap, we assessed the diversity, prevalence and coinfections of three ISVs (horizontally transmitted cripavirus, biparentally transmitted sigmavirus and maternally transmitted iflavirus) in 29 field populations of Queensland fruit fly, Australia's most significant horticultural pest, in the context of their different transmission modes. We detected new virus variant diversity. In contrast to the very high virus prevalence in laboratory populations, 46.8% of 293 field flies carried one virus and 4.8% had two viruses. Cripavirus and sigmavirus occurred in all regions, while iflavirus was restricted to subtropical and tropical regions. Cripavirus was most prevalent (37.5%), followed by sigmavirus (13.7%) and iflavirus (4.4%). Cripavirus coinfected some flies with either one of the two vertically transmitted viruses. However, sigmavirus did not coinfect individuals with iflavirus. Three different modelling approaches detected negative association patterns between sigmavirus and iflavirus, consistent with the absence of such coinfections in laboratory populations. This may be linked with their maternal transmission and the ineffective paternal transmission of sigmavirus. Furthermore, we found that, unlike sigmavirus and iflavirus, cripavirus load was higher in laboratory than field flies. Laboratory and mass‐rearing conditions may increase ISV prevalence and load due to increased transmission opportunities. We conclude that a combination of field and laboratory studies is needed to uncover ISV interactions and further our understanding of ISV epidemiology.

Xinmoviridae is a family of viruses with negative-sense RNA genomes of 9–14 kilobases. Xinmovirids typically infect beneficial and pest insects but their host range has not yet been investigated systematically and hence may be broader. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family of Xinmoviridae, which is available at ictv.global/report/xinmoviridae.

In April 2023, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by one new family, 14 new genera, and 140 new species. Two genera and 538 species were renamed. One species was moved, and four were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

In March 2022, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by two new families (bunyaviral Discoviridae and Tulasviridae), 41 new genera, and 98 new species. Three hundred forty-nine species were renamed and/or moved. The accidentally misspelled names of seven species were corrected. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.