Search Results (267)

A rare example of long-term elimination of Aedes aegypti occurred in Brisbane, where legislatively enforced removal of rainwater tanks led to its disappearance by the mid-1950s. However, widespread tank installation during a later drought reintroduced critical breeding habitat, enabling persistence in this subtropical region. With Ae. aegypti re-invading towns ~150 km north of Brisbane, we assessed the potential for sustained elimination. Using a genomics-informed simulation modeling framework, we integrated population genomic inference of connectivity and migration with entomological and environmental data to parameterize elimination scenarios. Genomic analyses revealed strong overall isolation among neighbouring populations in the region, with limited recent migration detected between the two southernmost populations, in Murgon and Wondai. We therefore focused simulations on these populations. Our results indicate that elimination is feasible with moderate releases of incompatible Wolbachia-infected (IIT) males (sorting error ≤ 10⁻⁶), provided non-compliant rainwater tanks are removed first. This combined strategy achieved >99% suppression and elimination in 35% of simulations in one town, whereas IIT alone resulted in moderate suppression (61–93%) and increased the risk of Wolbachia establishment at higher release ratios. Full article

Bemisia tabaci is a globally destructive agricultural pest and an efficient vector of begomoviruses, which cause recurrent epidemics across South Asia, including cotton leaf curl disease in Pakistan. Increasing evidence shows that bacterial endosymbionts play a central role in shaping whitefly biology, population dynamics, and vector competence. However, the distribution of these symbionts remains poorly resolved in Pakistan, a region where begomoviruses are persistent and widespread. This study investigated the cryptic species diversity, secondary endosymbiont composition and their infection frequency in B. tabaci populations collected from major agricultural regions of Pakistan. A total of 274 adult whiteflies belonging to Asia II-1 (n = 199), MEAM-1 (n = 67), Asia I (n = 7), and Asia II-8 (n = 1) were screened using a symbiont-specific PCR assay for six endosymbionts. The primary endosymbiont Candidatus Portiera aleyrodidarum was detected in all individuals, whereas five secondary endosymbionts (Arsenophonus, Cardinium, Hamiltonella, Wolbachia and Rickettsia) were identified with distinct cryptic species- and region-specific patterns. Notably, Arsenophonus was the most prevalent endosymbiont, occurring in 68% of Asia II-1, 100% of Asia I, and 21% of MEAM-1 individuals, with the highest regional prevalence in Punjab (80%) and Khyber Pakhtunkhwa (77%). Logistic regression analyses confirmed significantly higher infection probabilities in indigenous Asia II-1 populations. Network analysis revealed structured co-occurrence patterns, including strong negative associations between Arsenophonus and Hamiltonella. Phylogenetic analyses revealed close relatedness of Pakistani Arsenophonus strains to those reported from neighboring regions, indicating regional community rather than unique local diversification. The dominance of Arsenophonus in Pakistani whitefly populations is of particular significance, given its role in protecting begomoviruses within the insect vector and its implication in facilitating virus persistence and transmission. This study, for the first time in Pakistan, provides a comprehensive assessment of endosymbiont–cryptic species associations in Pakistani B. tabaci populations and highlights the dominant prevalence of Arsenophonus as a potential key player in local virus vector dynamics. Full article

Background and Objectives: New Caledonia, an archipelago in the South Pacific, experienced an unprecedented conjunction of prolonged border closure during the COVID-19 pandemic (2020 to 2022) and marked influence of the El Niño/Southern Oscillation (ENSO). This context provided a unique opportunity to explore how environmental drivers, island isolation, and socio-demographic factors interact to shape infectious disease dynamics. This study aimed to assess the respective and combined effects of climatic variability, travel restrictions, and socio-demographic factors on the dynamics of four priority infectious diseases. Materials and Methods: We retrospectively analysed data from 2017 to 2023 on four infectious diseases: leptospirosis, dengue, influenza, and hepatitis A (HAV). Satellite precipitation data and the Multivariate El Niño/Southern Oscillation Index (MEI) were used. Socio-demographic and economic variables were gathered. Statistical analyses employed descriptive analysis and Generalized Additive Mixed Models to evaluate the associations between climatic events, travel restrictions, and disease circulation using the communal level as a random effect and time (daily) as a spline effect. Results: We analysed 878 cases of leptospirosis, 165 of HAV, 6607 of influenza, and 7377 dengue cases. Influenza was associated with rainfall before lockdown (Odds Ratio (OR) 0.7, Confidence interval 95%, (CI95%), (0.6–0.8)) and disappeared during lockdown but resurged post-reopening losing its meteorological association. Dengue epidemics declined, coinciding with the Wolbachia program and border closure, and were associated with lower MEI (OR 0.78, CI95% (0.6–1) during the 2017 to 2020 period. HAV cases were correlated with the MEI (OR: 1.8, CI95% (1–3.3)). Leptospirosis cases were associated with cumulative rainfall (OR 1.12 (1.1–1.2)) and lower education (OR 1.04, CI95% (1–1.1)) and decreased with water supply (OR 0.7, CI95% (0.5–0.8)). Conclusions: Our findings highlight how climatic conditions, mobility restrictions, and socio-environmental inequities differentially shape infectious disease risks in island ecosystems. These results reinforce the need for integrated One Health surveillance that jointly addresses environmental change, social vulnerability, and infectious disease prevention. Full article

Wolbachia is an obligate endosymbiotic alphaproteobacterium that is widely distributed among insects. It also infects the European orthopteran Chorthippus parallelus parallelus (Cpp). In this subspecies, Wolbachia induces a reproductive barrier through uni- and bidirectional cytoplasmic incompatibilities. Recently, we found that it also modifies the expression of genes related to essential physiological pathways in Cpp. Here, we have analysed the influence of Wolbachia infection on the epigenetic profiles in Cpp gonads of infected and uninfected males and females, since they constitute Wolbachia’s main target. We characterised de novo nine genes related to epigenetic mechanisms and their transcriptional activity, together with global DNA methylation levels. The results indicate that Wolbachia influences the epigenetic mechanisms in Cpp mainly in females, inducing the expression of genes related to histone deacetylation and reducing the global DNA methylation percentage. This study provides the first evidence of Wolbachia’s ability to alter epigenetic processes in Cpp, increasing our understanding of this symbiotic relationship, with potential implications for the induced reproductive isolation within and between subspecies of C. parallelus. It also offers new insights into the molecular basis of host–symbiont biology in a group for which this information is rather scarce. Full article

Endosymbiotic bacteria in insects are known to influence plant–insect interactions by altering host plant physiology. This study reveals that the endosymbiont Wolbachia significantly impairs photosynthesis in cotton plants. Comparative transcriptomic analysis of cotton leaves infested by Wolbachia-infected spider mites (Tt-I) and uninfected spider mites (Tt-UI) identified 1912 differentially expressed genes (DEGs). Photosynthesis was the most adversely affected biological process, with 17 genes downregulated in the photosynthesis pathway (e.g., key genes psbW and PETF), as supported by GO and KEGG enrichment analyses. Gene co-expression network analysis further highlighted core genes involved in photosynthesis disruption and carbon fixation. Physiological assessments showed that Wolbachia infection led to significantly reduced chlorophyll content and elevated reactive oxygen species (ROS) levels, inducing oxidative stress. These findings demonstrate that Wolbachia disrupts cotton photosynthesis through transcriptional repression and ROS-mediated oxidative stress, providing novel insights into plant–insect-symbiont interactions and a theoretical basis for managing mite pests in cotton. Full article

Efficient egg collection is important for large-scale mosquito rearing, but it presents logistical challenges and often yields suboptimal egg numbers in mass rearing cages. Furthermore, uneven distribution of eggs on oviposition substrates can lead to higher fatality of the first instar (L1) larvae among overlapping/stacked eggs. Previous studies showed that incorporating darker hues into oviposition pots (ovipots) improves egg collection, yet few discussed designs of containers for use in mass rearing cages. Using a no-choice experimental setup, the number of eggs collected per female was determined in cages of Wolbachia-infected Aedes aegypti mosquitoes provided with different ovipots. The percentage of dead larvae among the stacked eggs was also determined. Based on this information, different prototypes of a more efficient, larger ovipot were evaluated in mass rearing cages. A black-bottom container with white crepe paper collected the most eggs per blood-fed female by promoting higher oviposition rates. A significantly lower percentage (0.31%) of dead L1 larvae were found among relatively sparser eggs compared to 0.96% among stacked eggs. A larger, black-bottom ovipot with oviposition papers positioned at the center of the container, demonstrated suitability for use in mass rearing cages, promoting better egg distribution and yield. Full article

Dirofilaria immitis constitutes a significant global veterinary burden and an emerging zoonotic risk. Despite decades of study, the structural evolution of its scientific landscape remains unexplored. This study provides a comprehensive longitudinal analysis of global research on D. immitis to evaluate its trajectory, intellectual structure, and conceptual shifts over the last eight decades. A systematic bibliometric analysis was conducted following PRISMA guidelines adapted for bibliometrics. Data were retrieved from Web of Science Core Collection and Scopus, covering the period from 1945 to 2025. After deduplication and manual screening, a final corpus of 3589 documents was analyzed using performance indicators and science mapping techniques to assess growth patterns, geographic leadership, collaboration networks, and thematic evolution. The field exhibits a mature profile with a sustained mean annual growth rate of 2.39%. Production is geographically polarized, with the United States and Italy acting as the primary research hubs, though international collaboration networks are increasingly integrating endemic regions in the Global South. Thematic analysis reveals a profound paradigm shift: while early research (1945–1980) focused on parasite morphology and clinical description, the 21st century is characterized by a multidisciplinary approach dominated by molecular biology, the study of the endosymbiont Wolbachia, and the genetic mechanisms of macrocyclic lactone resistance. The intellectual structure is currently organized into distinct but interconnected clusters, linking established clinical pathology with emerging genomic and environmental control strategies. Research on D. immitis has evolved from a classical parasitology discipline into a complex biomedical ecosystem aligned with the One Health framework. The persistence of the disease, driven by drug resistance and climate-mediated vector expansion, has catalyzed a transition toward integrative research models. Future control strategies must transcend geographic borders, combining advanced genomic surveillance with ecological modeling to mitigate the impact of this transboundary disease on both animal and human health. Full article

Haiti is a Caribbean country of about 11 million people with a high burden of mosquito-transmitted disease and limited vector control, thereby making effective operational mosquito control of high importance. Previous studies have examined vector-borne disease burden and insecticide resistance markers in Haitian Aedes and Anopheles mosquitoes, but not Culex species. In this study, we examined collections of Culex quinquefasciatus from 12 locations in northern and southern Haiti for the presence of markers of insecticide resistance (using a variety of target-site mutations and biochemical assays) and pathogens (using a deep-sequencing microbiome workflow). The metagenomic analysis identified Wolbachia, Rhabdoviridae, and Plasmodium infections in all sample pools at relatively high levels, along with less frequent detections of other potential pathogens. Insecticide resistance marker examination identified variable frequencies of knockdown resistance and acetylcholinesterase resistance mutations, as well as variation in resistance-associated enzymatic activities in these populations. These findings indicate that insecticide resistance to pyrethroid and organophosphate insecticides is likely. Although there was variation among Culex mosquito populations and no clear activity pattern, enzymatic activity was significantly higher at the southern sites than at the northern sites. Similar findings in Cx. quinquefasciatus populations in other locations in the Americas strongly suggest that vector control with pyrethroid and organophosphate adulticides may be of limited efficacy. Full article

Mosquito-borne diseases are an emerging public health challenge in Europe, driven by the spread of invasive mosquito species capable of sustaining outbreaks of tropical arboviral diseases. Rising temperatures, shifting precipitation patterns, human-driven habitat changes, and prolonged transmission seasons have increased the risk of dengue, chikungunya, and West Nile virus outbreaks, among other vector-borne diseases. Effective control requires a multifaceted approach, combining traditional and novel methods with advanced surveillance technologies and community involvement. However, growing insecticide resistance and concerns about insecticide use highlight the need for more prudent management of current tools and the development of innovative alternatives. Genetic control strategies, including the Sterile Insect Technique (SIT), Wolbachia-based approaches, and genetically modified (GM) mosquitoes, offer promising solutions but still face scientific, regulatory, and societal challenges. This review explores the current landscape of mosquito-borne disease control in Mediterranean Europe, emphasizing key challenges and emerging solutions. An integrated approach that strengthens surveillance, promotes sustainable control methods, and incorporates novel biotechnological tools supported by smart technologies will be essential to reduce the future burden of mosquito-borne diseases in the region. Full article

During the 2024/2025 wet season, Townsville had its first sustained autochthonous outbreak of dengue disease caused by dengue virus type 2 (DENV-2), the second locally transmitted outbreak of dengue since 2014 following the introduction of wMel strain Wolbachia-infected mosquitoes, a control strategy for dengue virus (DENV) and other Aedes-transmitted arboviruses. In comparison to two recorded locally acquired cases of dengue in 2020, the 2024/2025 outbreak resulted in sixteen cases in two inner-city suburbs of Townsville during the wet season associated with higher-than-average rainfall. This second dengue outbreak since 2014 highlights that Townsville and other north Queensland communities where Wolbachia mosquito programs have been deployed remain vulnerable to DENV incursions and local disease outbreaks despite the apparent high coverage of Wolbachia-infected mosquitoes. Whilst these control strategies have likely contributed to a reduction in the number and frequency of autochthonous DENV outbreaks in north Queensland, ongoing maintenance and monitoring of Wolbachia-infected mosquito coverage is necessary, together with timely review and improvement in dengue awareness and prevention health promotion activities in the community. Full article

The Incompatible Insect Technique (IIT) is a species-specific, eco-friendly mosquito control method that relies on releasing Wolbachia-infected males, which induce cytoplasmic incompatibility (CI), rendering eggs inviable when mating with wild females. Aiming at optimizing IIT protocols in terms of cost-effectiveness, data on incompatible male dispersal and survival and the distance- and time-related impact of induced sterility are fundamental. This study plans to fill this gap and reports findings from a two-year field trial (2022–2023) at the ENEA-Casaccia Research Center, based on single-spot releases of incompatible Aedes albopictus males (ARwP strain). Male releases were carried out in late September 2022 (~15,000 released males) and the early Ae. albopictus season (at the end of June 2023; ~24,000 released males). Fifty-eight ovitraps were located at a 20–900 m distance from the ARwP release spot and were monitored weekly from May to November to assess egg hatching rates and measure CI effects in relation to both distance and time. Following the 2023 release, samples of adults were collected at increasing distances from the release site and at multiple post-release time points to assess, individually, wild female fertility and ARwP male dispersal and survival using Wolbachia as a genetic marker. Statistical analyses revealed that: (a) the highest reduction in the egg hatching was found within 100 m from the release spot (46.5% and 19.9%, respectively, in 2022 and 2023) but remained significant even at greater distances (29.9% and 7.7% at 300 m, respectively, in 2022 and 2023); (b) accordingly, the highest reduction in the wild female fertility occurred within 100 m from the release spot (47.3%), but similar effects were recognizable up to 600 m; (c) the overflooding ratio of the ARwP males did not significantly differ between 3 and 11 days after the release, with ARwP males remaining active up to 18 days and dispersing as far as 400 m. These results demonstrate the potential of localized, non-inundative IIT trials to furnish clues for the setup of spatially optimized release strategies, especially in scaled-up applications. The study also emphasizes the need for standardized assessment tools and further research regarding environmental and behavioral factors influencing long-term suppression outcomes. Full article

Hypera postica (Gyllenhal) is a major pest of alfalfa. We combined mitochondrial COI and CytB gene sequences to characterize the genetic diversity of 20 geographic populations of H. postica across Xinjiang, China, and to elucidate their lineage relationships at both regional and global scales. We found that Nucleotide diversity (Pi) was markedly higher in western Xinjiang populations (Pi > 0.016), specifically Wusu (0.023), Tekes (0.023), Jinghe (0.023), Wenquan (0.021), Bole (0.021), Habahe (0.020), Nilka (0.020), Tacheng (0.019), Toli (0.018), Altay (0.017), Emin (0.016), Xinyuan (0.016), and Zhaosu (0.016), whereas central Xinjiang populations exhibited substantially lower diversity (Pi < 0.014), including Shawan (0.014), Qitai (0.011), Jimsar (0.007), Urumqi (0.004), Hutubi (0.003), Fukang (0.001), and Manas (0.001). Pairwise F_ST analysis revealed pronounced genetic divergence between the western Xinjiang group (Altay, Bole, Wenquan, Tacheng, Emin, Toli, Nilka, Xinyuan, Tekes, Zhaosu) and the central Xinjiang group (Qitai, Urumqi, Fukang, Habahe, Hutubi, Jimsar, Shawan, Manas). At the global level, H. postica can be divided into two major phylogroups: the Western and Eastern lineages. All Xinjiang populations belong to the Eastern lineage. Haplotype network analysis identified two distinct sublineages, western and central Xinjiang, with H2 and H26 as their respective dominant shared haplotypes; both are unique to China. Both maximum likelihood (ML) and Bayesian phylogenetic trees robustly support the central Xinjiang lineage as a distinct clade. Neutrality tests provided strong evidence of recent demographic expansion across the Xinjiang H. postica population as a whole (Fu’s Fs = −21.987, p < 0.05), with particularly pronounced signals in Hutubi (HTB: Tajima’s D = −1.966, Fu’s Fs = −0.781, p < 0.05), Jimsar (JMSE: Tajima’s D = −2.176, Fu’s Fs = −0.962, p < 0.01), and Wenquan (WQ: Fu’s Fs = −11.159, p < 0.01). Our results reveal a clear phylogeographic split within Xinjiang H. postica populations, comprising western and central sub-lineages, with the western sub-lineage likely representing ancestral lineage. The western Xinjiang sub-lineage appears to be shaped primarily by mountainous topography, whereas the central Xinjiang sub-lineage likely results from the combined effects of piedmont plain geography and infection with the endosymbiont Wolbachia strain wHypera4. Full article

L. pratensis is a significant pest of cotton. Clarifying the intestinal bacterial structure of L. pratensis can provide a theoretical basis for the development of new pest biological control strategies. In this study, high-throughput sequencing was employed to characterize the intestinal bacterial communities across five L. pratensis populations, and the functions of their core metabolic pathways were predicted. The results showed that the intestinal bacterial communities of the five L. pratensis populations comprised 16 phyla, 25 classes, 54 orders, 85 families, 133 genera, and 187 species. Diversity analysis revealed that the diversity of the intestinal bacterial community exhibited a dynamic trend of first increasing and then decreasing during the pest’s growth and development. Specifically, the Shannon and Simpson diversity indices of the nymphal stage were significantly higher than those of the egg and adult stages (p < 0.05). The dominant phylum, class, order, family, genus and species shared by the five groups were Proteobacteria (93.17%), Gammaproteobacteria (48.71%), Rickettsiales (43.83%), Anaplasmataceae (49.39%), Wolbachia (43.83%) and Wolbachia (43.82%). Among them, Acinetobacter was mainly found in the first instar nymph stage, and Serratia was mainly distributed in the fifth instar nymph and female and male adults. Functional prediction results showed that the intestinal bacterial community was mainly enriched in core pathways, including metabolism, genetic information processing, and environmental information processing. This study provides a new target for green prevention and control of L. pratensis and also provides a theoretical basis for further elucidating the succession law and functional mechanism of its gut microbiota. Full article

Wolbachia is an endosymbiotic bacterium widespread in invertebrates that causes various reproductive effects, including cytoplasmic incompatibility, feminization, male killing, and the induction of parthenogenesis (PI). PI-Wolbachia wRem converts Telenomus remus, an egg parasitoid of Spodoptera frugiperda, from arrhenotokous reproduction (male-producing) to thelytokous reproduction (female-producing). Long-term symbiosis between egg parasitoids and Wolbachia has been shown to lead to reproductive barriers and “female functional virginity,” causing progressive and potentially irreversible sex ratio imbalances. However, whether such reproductive barriers occur in T. remus remains unknown, which has important implications for biological control programs utilizing this parasitoid. To address this question, we cured wRem using tetracycline and conducted crossing experiments with naturally uninfected strains (W-). The results indicated that the cured strain (Wcure) retained normal sexual reproductive capability, with self-crossing fertilization rates comparable to those of W- strains. However, first-generation hybridization between Wcure and W- strains produced strongly male-biased offspring (male proportion: 94.3% and 85.8% for W-♂ × Wcure♀ and Wcure♂ × W-♀, respectively), indicating substantial reproductive incompatibility. Notably, an asymmetric pattern was observed between reciprocal crosses. In second-generation hybridization experiments, hybrid females (W-/Wcure) mated with W- or Wcure males showed markedly recovered sex ratios (male proportion: 14.3% and 15.6%, respectively), although total offspring numbers remained lower than in self-crossing groups. These results suggest that the reproductive incompatibility in T. remus differs from female functional virginity and is more consistent with mitonuclear incompatibility arising from population divergence. The partial recovery in second-generation hybrids indicates that surviving F1 hybrid females likely represent individuals selected for compatibility, rather than exhibiting progressive deterioration of sexual function. These findings offer insights into Wolbachia’s impact on parasitoid reproduction and highlight key considerations for biological control applications, underscoring the importance of evaluating reproductive barriers before deploying cured strains and preventing symbiont loss within populations. Full article

Endosymbiotic bacteria influence the ecology and evolution of insects through complex associations within host cells. To explore how these relationships vary among environments and taxa, we examined 1028 insect specimens from 14 orders across Korea for infections by three representative endosymbionts (Wolbachia, Rickettsia, and Spiroplasma). Overall, 33.8% of specimens were infected, with single infections predominating and co-infections remaining relatively less common. Weak-to-modest but statistically significant associations were detected between several symbiont pairs (Rickettsia–Spiroplasma, Wolbachia–Spiroplasma, and Wolbachia–Rickettsia). Infection rates exhibited no significant variation among host orders except for Spiroplasma, and Wolbachia infections were more frequently detected in terrestrial than in aquatic insects. These results indicate that endosymbiont infection patterns might be shaped by factors operating at multiple biological scales, including host taxonomy and habitat types. As this study relied on polymerase chain reaction detection, infection frequencies should be interpreted as comparative rather than absolute measures. This survey provides baseline data that might help characterize regional patterns of endosymbiont distributions and their variation across taxonomic and ecological contexts. Full article