Explore the vast range of titles available.

Dinocampus coccinellae (Schrank) is a braconid parasitoid of ladybird beetles (Coleoptera: Coccinellidae) and has exceptionally wide geographical and host ranges. Based on published and unpublished sources Dinocampus coccinellae probably occurs throughout the temperate, subtropical and tropical climatic zones, but some regions, such as sub-Saharan Africa (except its southernmost part) and the Malay Archipelago, have not so far been surveyed for this wasp. In most of its extensive range D. coccinellae was present before the widespread use of classical biological control. It is likely, however, to have reached some oceanic islands and archipelagos at a later date, along with ladybirds used as biocontrol agents. At least 72 species of Coccinellidae are hosts of D. coccinellae. Three of them, Vibidia duodecimguttata (Poda), Calvia decemguttata (L.) and Coccinella miranda Wollaston, are reported here for the fi rst time as hosts of this parasitoid. The most often reported host of D. coccinellae worldwide is Coccinella septempunctata L. followed by Harmonia axyridis (Pallas), Coleomegilla maculata (De Geer) and Hippodamia convergens Guerin.

Background Bacteriophages and bacteria frequently occupy the same ecological niches, driving complex and dynamic host–virus interactions. In Pseudomonas aeruginosa , phages from the Migulavirinae subfamily, tail fibre proteins (TFPs) are crucial to host recognition. These proteins, located within the phage tail structure, are subject to frequent recombination and may play a key role in shaping host range. This study investigates the molecular basis of host specificity in Litunavirus and Luzseptimavirus phages, focusing on the structure and variation of their TFPs. Results Host spectrum analysis divided phages into three categories; however, contrary to expectations, no direct correlation was found between TFP recombination history and host range, most likely because subsequent single amino acid changes in the pyocin knob regions, critical for adsorption, altered the host spectrum after the recombination event. Notably, phages sharing highly similar pyocin knob 2 domain architectures displayed identical host spectra, suggesting a strong link between this region and host specificity. Despite high sequence variability, all TFPs adopted a conserved trimeric fold with five regions: N-terminal, GrpE-like, GDSL-like with a carbohydrate-binding module, pyocin knob, and C-terminal. Structural similarities to bacterial PilA and pyocins were noted. Variation in the pyocin knob region, especially substitutions involving polar residues, was partially correlated with host range, likely via hydrogen bonding with the O-antigen. The GrpE-like domain resembled type IV pili, suggesting a role in reversible attachment, while the GDSL-like domain may support enzymatic processing of the O-antigen. Conclusions Our findings support a multi-step adsorption mechanism of Migulavirinae phages, initiated by random encounters with the bacterial surface, followed by specific, stable interactions between the pyocin knob region and the bacterial lipopolysaccharide (LPS) O-antigen. Final stabilization involves additional interactions with the LPS core region. While the GrpE-like domain may contribute to transient stabilization near the surface, its structural similarity to PilA suggests a possible evolutionary convergence rather than a direct pilus-binding function. Despite high sequence variability, TFPs maintain conserved structural features, allowing for modular adaptations that precisely adjust host specificity. Importantly, the lack of a direct link between TFP recombination and host range suggests that factors beyond recombination influence phage host specificity.

We investigated the patterns of phylogenetic and functional (dis)similarity in the species composition of host spectra between co-habitating generalist flea species in regional assemblages from four continents (Europe, Asia, North America and Africa) using a recently developed ordination approach (Double Similarity Principal Component Analysis). From the functional perspective, we considered physiological [body mass and basal metabolic rate (BMR)] and ecological (shelter depth and complexity) host traits. We asked (a) whether host phylogeny, physiology or ecology is the main driver of (dis)similarities between flea host spectra and (b) whether the patterns of phylogenetic and functional (dis)similarity in host spectra vary between flea assemblages from different continents. Phylogenetic similarity between the host spectra was highest in Africa, lowest in North America and moderate in Europe and Asia. In each assemblage, phylogenetic clusters of hosts dominating in the host spectra could be distinguished. The functional similarity between the host spectra of co-occurring fleas was low for shelter structure in all assemblages and much higher for body mass and BMR in three of the four assemblages (except North America). We conclude that host phylogeny and shelter structure are the main drivers of (dis)similarity between the host spectra of co-habitating fleas. However, the effects of these factors on the patterns of (dis)similarity varied across continents.

Recent years have witnessed the discovery of several new viruses belonging to the family Arteriviridae, expanding the known diversity and host range of this group of complex RNA viruses. Although the pathological relevance of these new viruses is not always clear, several well-studied members of the family Arteriviridae are known to be important animal pathogens. Here, we report the complete genome sequences of four new arterivirus variants, belonging to two putative novel species. These new arteriviruses were discovered in African rodents and were given the names Lopma virus and Praja virus. Their genomes follow the characteristic genome organization of all known arteriviruses, even though they are only distantly related to currently known rodent-borne arteriviruses. Phylogenetic analysis shows that Lopma virus clusters in the subfamily Variarterivirinae, while Praja virus clusters near members of the subfamily Heroarterivirinae: the yet undescribed forest pouched giant rat arterivirus and hedgehog arterivirus 1. A co-divergence analysis of rodent-borne arteriviruses confirms that they share similar phylogenetic patterns with their hosts, with only very few cases of host shifting events throughout their evolutionary history. Overall, the genomes described here and their unique clustering with other arteriviruses further illustrate the existence of multiple rodent-borne arterivirus lineages, expanding our knowledge of the evolutionary origin of these viruses.

The parasitic wasp Anaphes flavipes (Förster, 1841) (Hymenoptera: Mymaridae) is an important egg parasitoid of cereal leaf beetles. Some species of cereal leaf beetle co-occur in the same localities, but the host specificity of the wasp to these crop pests has not yet been examined in detail. A lack of knowledge of host specificity can have a negative effect on the use of this wasps in biological control programs addressed to specific pest species or genus. In this study, laboratory experiments were conducted to assess the host specificity of A. flavipes for three species of cereal leaf beetles (Oulema duftschmidi Redtenbacher, 1874, Oulema gallaeciana Heyden, 1879 and Oulema melanopus Linnaeus, 1758) in central Europe. For the first time, a new host defence against egg parasitoids occurring in O. gallaeciana from localities in the Czech Republic, a strong dark sticky layer on the egg surface, was found and described. The host specificity of A. flavipes was studied in the locality with the presence of this defence on O. gallaeciana eggs (the dark sticky layer) (Czech Republic) and in a control locality (Germany), where no such host defence was observed. Contrary to the idea that a host defence mechanism can change the host specificity of parasitoids, the wasps from these two localities did not display any differences in that. Respectively, even though it has been observed that eggs with sticky dark layer can prevent parasitization, the overall rate of parasitization of the three species of cereal beetles has not been affected. However, in our view, new host defence can influence the effects of biological control, as eggs of all Oulema spp. in the locality are protected against parasitization from the wasps stuck on the sticky layer of the host eggs of O. gallaeciana.

Feline morbillivirus (FeMV) was first isolated in 2012 from stray cats in Hong Kong. It has been found in association with tubulointerstitial nephritis (TIN), the most common cause of feline chronic kidney disease (CKD). However, viral host spectrum and virus tropism go beyond the domestic cat and kidney tissues. The viral genetic diversity of FeMV is extensive, but it is not known if this is clinically relevant. Urine and kidney tissues have been widely tested in attempts to confirm associations between FeMV infection and renal disease, but samples from both healthy and sick cats can test positive and some cross-sectional studies have not found associations between FeMV infection and CKD. There is also evidence for acute kidney injury following infection with FeMV. The results of prevalence studies differ greatly depending on the population tested and methodologies used for detection, but worldwide distribution of FeMV has been shown. Experimental studies have confirmed previous field observations that higher viral loads are present in the urine compared to other tissues, and renal TIN lesions associated with FeMV antigen have been demonstrated, alongside virus lymphotropism and viraemia-associated lymphopenia. Longitudinal field studies have revealed persistent viral shedding in urine, although infection can be cleared spontaneously.

The Oenococcus genus comprises four recognized species, and members have been found in different types of beverages, including wine, kefir, cider and kombucha. In this work, we implemented two complementary strategies to assess whether oenococcal hosts of different species and habitats were connected through their bacteriophages. First, we investigated the diversity of CRISPR-Cas systems using a genome-mining approach, and CRISPR-endowed strains were identified in three species. A census of the spacers from the four identified CRISPR-Cas loci showed that each spacer space was mostly dominated by species-specific sequences. Yet, we characterized a limited records of potentially recent and also ancient infections between O. kitaharae and O. sicerae and phages of O. oeni, suggesting that some related phages have interacted in diverse ways with their Oenococcus hosts over evolutionary time. Second, phage-host interaction analyses were performed experimentally with a diversified panel of phages and strains. None of the tested phages could infect strains across the species barrier. Yet, some infections occurred between phages and hosts from distinct beverages in the O. oeni species.

Defining the whole spectrum of potential hosts of a parasite has large epidemiological and evolutionary implications in biology. Specialized parasites might be able to occasionally exploit a range of different host species, increasing the individual survival and the chances of successful dispersal. For long time Paraceras melis has been considered a specific flea of European badger Meles meles. Anyway, it has occasionally been reported on different hosts. In this work, we summarize the host spectrum of P. melis from literature and we report its first detection on a bat host. Ten species were identified as occasional hosts, man included, and the plasticity of this flea in host exploitation is noteworthy because of possible increase of pathogens transmission to humans and domestic species.

Root hemiparasites are green plants which attach to roots of other plants and extract solutes from the host-root xylem parasitically. They frequently act as keystone species by affecting competitive relations in plant communities and altering mineral nutrient cycling. Understanding their ecology has been hindered by the difficulty to identify host associations of hemiparasitic plants growing in natural conditions. Direct examination of host associations is only possible at sites with specific soil types (e.g. sandy substrates) that allow host roots to be traced to the shoot to identify the host species. We investigated the possibility of using a DNA barcodingbased approach to identify host associations of root hemiparasites growing naturally. Host associations of Melampyrum nemorosum, Rhinanthus major and Rhinanthus minor were investigated. Their root systems were washed free of soil to reveal haustorial connections. Host-root fragments were subjected to DNA extraction and the plastid DNA trnL intron was sequenced. The functioning of haustoria was examined in semi-thin anatomical sections. The analysis of the DNA of host roots yielded a ca 60% success rate. The Rhinanthus species were confirmed to attack mostly grasses and legumes. By contrast, Melampyrum nemorosum attached mainly to plants of Rosaceae and Asteraceae. In addition, both conspecific and heterospecific connections between the hemiparasites were frequently observed. Our study demonstrates the usefulness of the DNA barcoding approach for identifying host associations of root hemiparasites at sites where tracing host roots to their shoot is not possible due to soil structure or high rooting density.

This study explores the food plant spectrum of the sugar beet weevil (Asproparthenis punctiventris Germar; Coleoptera: Curculionidae), one of the most important pests of sugar beet (Beta vulgaris subsp. vulgaris Altissima group). It examines the potential of various weeds and other plants to maintain populations of A. punctiventris adults and larvae outside sugar beet fields. To this end, leaf consumption of females and males on twelve Amaranthaceae and six Polygonaceae species was compared over a 24-h period in a laboratory environment. Both sexes consumed the greatest amount of leaf mass from Beta spp. and on average about a third less from Atriplex spp., indicating that these plants have the highest nutritional value for A. punctiventris. Weevils consumed between 30 and 60% of the amount of A. retroflexus and Chenopodium spp. than they fed on sugar beet leaves. Like Spinacia oleracea (Amaranthaceae), plant species of the Polygonaceae family were hardly or not at all fed on. Mated females generally consumed more leaf mass than unmated, especially from Chenopodium spp. and A. retroflexus, i.e. plants with low feeding value. Experiments with potted plants revealed that the most and heaviest 4th instar larvae developed on sugar beet, while fewer individuals with lesser weight were found on B. vulgaris subsp. maritima and A. hortensis. Very few larvae were able to develop on C. album, and none on A. retroflexus. To prevent promotion of pest population, special attention should be paid to the control of weeds from the Amaranthaceae family in sugar beet growing areas.