Trypanosomes are important global livestock and human pathogens of public health importance. Elucidating the chemical mechanisms of trypanosome-relevant host interactions can enhance the design and development of a novel, next-generation trypanosomosis diagnostics. However, it is unknown how trypanosome infection affects livestock volatile odors. Here, we show that Trypanosoma congolense and Trypanosoma vivax infections induced dihydro-β- ionone and junenol, while abundance of dihydro-α-ionone, phenolics, p-cresol, and 3-propylphenol significantly elevated in cow urine. These biomarkers of trypanosome infection are conserved in cow breath and the urine metabolites of naturally infected cows, regardless of population, diet, or environment differences. Furthermore, treating trypanosome-infected cows reduced the levels of these indicators back to the pre-infection levels. Finally, we demonstrated that the potential of some specific biomarkers of phenolic origin may be used to detect active trypanosome infections, including low-level infections that are not detectable by microscopy. The sensitivity and specificity of biomarkers detection are suited for rapid, robust, and non-invasive trypanosomosis diagnosis under field conditions.

Olfaction is orchestrated at different stages and involves various proteins at each step. For example, odorant-binding proteins (OBPs) are soluble proteins found in sensillum lymph that might encounter odorants before reaching the odorant receptors. In tsetse flies, the function of OBPs in olfaction is less understood. Here, we investigated the role of OBPs in Glossina fuscipes fuscipes olfaction, the main vector of sleeping sickness, using multidisciplinary approaches. Our tissue expression study demonstrated that GffLush was conserved in legs and antenna in both sexes, whereas GffObp44 and GffObp69 were expressed in the legs but absent in the antenna. GffObp99 was absent in the female antenna but expressed in the male antenna. Short odorant exposure induced a fast alteration in the transcription of OBP genes. Furthermore, we successfully silenced a specific OBP expressed in the antenna via dsRNAi feeding to decipher its function. We found that silencing OBPs that interact with 1-octen-3-ol significantly abolished flies’ attraction to 1-octen-3-ol, a known attractant for tsetse fly. However, OBPs that demonstrated a weak interaction with 1-octen-3-ol did not affect the behavioral response, even though it was successfully silenced. Thus, OBPs’ selective interaction with ligands, their expression in the antenna and their significant impact on behavior when silenced demonstrated their direct involvement in olfaction.

The ability of ticks to interact and adapt to different ecologies and hosts determines their vectorial competence for various pathogens; however, ticks-livestock-pathogens interaction studies are limited. With our ticks-hosts-pathogens interface studies, we found 14 species of hard ticks feeding on various livestock. Ticks showed a strong preference for one-humped camels ( Camelus dromedarius ). The camel nostril was the most preferred predilection site. The most prevalent tick species on camels was Hyalomma rufipes . We found two novel Amblyomma gemma variants which are distinct both morphologically and genetically from previously described Amblyomma gemma . The signature odors from camel breath and body were attractive to adult H. rufipes , demonstrating ticks utilize camel-derived metabolites to find their host. Our research shows that H. rufipes and camel hosts have unique and shared pathogens showing H. rufipes ’ vector and dromedary camel’s reservoir host qualities. Our study unravels the dynamic interactions between hard ticks, pathogens, and host camels that all influence the likelihood of pathogen adaptation and transmission dynamics. IMPORTANCE: Ticks are obligatory hematophagous arachnids, serving as vectors for a wide array of pathogens that can be transmitted to animals and humans. The ability of ticks to acquire and transmit various pathogens depends on their attraction to quality reservoir hosts and the survival of the pathogens in ticks’ gut and other tissues. However, the complex dynamics of tick-pathogen interaction and host-seeking behavior remain understudied. This investigation revealed notable variation in tick preference for domestic animals, with camel being the most preferred host. Moreover, our spatial analysis of tick attachment sites showed nostrils are the most preferred sites by various tick species. Our epidemiology data showed variation in the pathogens harbored by camel (host) and vector ( Hyalomma rufipes ), demonstrating the camel’s efficiency as reservoir host and ticks’ vector competence for various pathogens. With our behavioral experiment using H. rufipes and its preferred host’s (camel) breath and body signature odors, we identified novel attractants for H. rufipes , thus offering new avenues for combating tick-borne diseases. Overall, our study presents novel insights into how multiple factors shape tick-host-pathogen interaction.

Dung beetle larvae are consumed globally, yet their gut microbiota across different geographical locations remains largely unexplored. This study examined the diversity and composition of the gut microbiota of two edible dung beetle species, Cetonia aurata and Rhinoceros beetle (Oryctes sp.), from three sites in Kenya. Using advanced molecular techniques, bacterial and fungal communities were sequenced. The most abundant bacterial phyla in C. aurata were Firmicutes (42.10%) and Bacteroidota (32.50%), while Oryctes sp. had higher levels of Proteobacteria (35.00%), Actinobacteriota (11.40%) and Desulfobacterota (7.40%). Fungal communities were dominated by Lecanoromycetes (92.60%) in Oryctes sp. and Saccharomycetes (92.60%) in C. aurata. Beta diversity analysis revealed that neither species phylogeny nor larval location significantly influenced the presence of specific microbes. Pathways related to nitrogen and carbon degradation were predicted in bacteria like Bacillus, Pseudomonas mosselii, and Proteiniphilum. This implies that bacteria and fungi from the gut of dung beetle larvae could be ideal targets for potential bio‐resource to eliminate waste pollution and opened an important window of opportunity for bio-based economy solutions. This work offers very practical solutions that have great business potential that can create a gigantic market ranging from functional foods to dietary supplements and therapeutic applications.

Hippobosca camelina (camel ked) is an obligate hematophagous ectoparasite that infests camels. Hematophagy inflicts painful bites, leading to myiasis, anae

Off-host ticks must integrate host-associated cues with environmental signals that govern questing, microhabitat selection and water balance, yet the relative importance of these sensory modalities remains poorly understood across species occupying contrasting ecological niches. Resolving this variation is important for understanding tick behavioural ecology and for designing species-targeted surveillance and control tools. We investigated the responses of four Afrotropical ixodid ticks of veterinary and public-health importance Amblyomma gemma, Hyalomma rufipes, Rhipicephalus appendiculatus, and Rhipicephalus pulchellus, representing contrasting ecological and behavioural strategies. Here, we investigated the behavioural responses of four Afrotropical ixodid ticks, Amblyomma gemma, Hyalomma rufipes, Rhipicephalus appendiculatus, and Rhipicephalus pulchellus, we explored this behavior using beetroot as a source of earthy metabolites such as geosmin (Lu et al., 2003), a visual cue and humidity source. Beetroot peel attracted A. gemma and R. appendiculatus, elicited weaker and more variable responses in R. pulchellus, and produced no consistent attraction in H. rufipes. Headspace analysis identified myrcene, limonene, dodecane, tetradecane and geosmin as the major volatile compounds. However, none of these compounds, when tested individually, reproduced the attraction elicited by intact beetroot peel. Geosmin produced weak and inconsistent responses across the tested concentrations, while limonene induced significant avoidance in R. appendiculatus. In contrast, A. gemma and R. appendiculatus were consistently attracted to humid conditions, closely matching their responses to beetroot peel and indicating that hygrotaxis was the primary driver of attraction. H. rufipes and R. pulchellus showed little or no response to increased humidity. Colour preference assays further revealed that A. gemma, R. appendiculatus and R. pulchellus generally preferred white over darker colours, whereas H. rufipes preferentially oriented towards black and red. Moisture and colour provided stronger and more consistent orientation signals. Integrating humidity, visual contrast and biologically relevant odour blends may consequently provide a more effective basis for species-targeted tick surveillance and behavioural control than reliance on individual semiochemicals alone.