Moths of the genus Gazalina are implicated in the etiology of Seasonal Hyperacute Panuveitis (SHAPU), an enigmatic eye disease prevalent in Nepal. However, the precise causative species has remained unconfirmed due to a historical reliance on purely morphological identification. To definitively identify the responsible species, we collected Gazalina specimens from Dhorpatan Municipality, one of the epicentres of the SHAPU outbreak in Baglung District, western Nepal. We employed an integrative taxonomic approach, combining morphological evaluation with molecular phylogenetic analysis of a fragment of the cytochrome c oxidase subunit I (COI, 657 bp) gene. Morphological assessment suggested the specimens as Gazalina chrysolopha, based on the presence of a distinctive golden abdominal tuft of setae in females and three medial forewing lines. Maximum likelihood phylogenetic analysis on COI gene sequences corroborated this, revealing that the outbreak specimens form a monophyletic clade with G. chrysolopha from India and Pakistan. Additionally, genetic distance analysis demonstrated a minimal divergence (3.69%) between the Nepalese specimens and the Indian G. chrysolopha population. This study provides the first robust molecular evidence confirming G. chrysolopha as the biological agent associated with SHAPU outbreaks in Nepal. Future research should prioritise fine-scale distributional mapping of G. chrysolopha and investigate the evolutionary history of the genus across the Hindu-Kush Himalayas.

Accurate estimation of mosquito age is critical for malaria surveillance, as only older female Anopheles mosquitoes can transmit the parasite. Traditional age-grading methods include the Polovodova technique in which dilatations on the ovarian pedicel to tally completed gonotrophic cycles (GC) are counted. Despite their widespread use, these techniques remain poorly validated under realistic operational conditions, with limited evidence on their precision and accuracy across different parity rates, GC, and species. In this study, the accuracy and precision of the Polovodova method were evaluated across multiple age-graders and species under both laboratory and field conditions. A blinded validation study was conducted using laboratory-reared Anopheles arabiensis and Anopheles funestus (N > 3,600) spanning 4 GC and field-collected mosquitoes from Ulanga district, Tanzania (N = 600). Three blinded researchers performed dissections and readings, while a fourth unblinded researcher served as the reference reader (R0) to obtain ground truth (for parity) or assumed truth (for GC) for laboratory mosquitoes. Accuracy and precision for parity and GC classification were assessed using pairwise inter-rater comparisons, percent agreement, Fleiss' kappa, and Cohen's kappa (κ) statistics. For field mosquitoes, which had no age-referenced group, only precision was assessed. The Polovodova method accurately classified parity in both species, correctly identifying 98% to 100% of nulliparous and 94% to 96% of parous mosquitoes compared with the reference dataset. Inter-rater reliability for parity was almost perfect in An. arabiensis and An. funestus (κ = 0.81 to 0.83), with 82% to 96% pairwise agreement. GC classification was highly accurate for early stages (GC0 to GC2: 85% to 100%) but declined at later stages GC4 (34% to 46%), reflecting systematic underestimation of mosquito age. Overall GC reliability was moderate (κ = 0.56 to 0.59). Field classifications showed almost perfect agreement (κ = 0.87 to 0.88), supporting operational applicability. The Polovodova method provides robust estimates of parity and early gonotrophic-cycle status in Anopheles mosquitoes, but late-cycle classifications are more prone to reader disagreement and systematic underestimation. Operational use should therefore rely on trained multiple-reader workflows, including adjudication of discordant or late-cycle specimens, rather than single-reader classification. These findings provide empirical benchmarks for quality-assured Polovodova age-grading in malaria vector surveillance and intervention evaluation.

A case of trombiculosis is presented at the Estación de Biología Chamela in Jalisco, Mexico. This occurred during an expedition in search of parasites in the fall of 2024. One of the participants presented small red macules on her shins and ankles, and when these were observed with a portable magnifying glass, the presence of chiggers (Trombiculidae) was confirmed. The mites were identified as Eutrombicula alfreddugesi (Oudemans), which caused severe trombiculosis due to hypersensitivity in the affected person. In addition to the morphological diagnosis of the chiggers found, a clinical description of the case is presented.

We evaluated the efficacy of 5 systemic insecticide compounds, each incorporated into edible baits to control flea (Siphonaptera) vectors of the plague bacterium Yersinia pestis (Lehmann and Neumann), with brown rats (Rattus norvegicus, Berkenhout) and rock squirrels (Otospermophilus variegatus, Erxleben) in a laboratory environment. Rodents were exposed to diets lacking or containing insecticides for 24 h at which point adult Ctenocephalides felis (Bouché), Xenopsylla cheopis (Rothschild), or Oropsylla montana (Baker) were applied to rodents. Fleas were monitored for survival 1 d later and subsequent time points to evaluate residual efficacy, with relative comparisons of survival rates for individual fleas applied to nontreated and treated hosts. With brown rats, cythioate was ineffective in suppressing fleas after 1 d; nitenpyram and selamectin were ineffective after 7 to 8 d. Imidacloprid suppressed C. felis survival on rats by 94% at day 1 but efficacy declined to 11% by day 8. Fipronil applied orally to rats suppressed the survival of C. felis and X. cheopis by 52% to 95% and 45% to 96% at days 1 and 7 to 8, respectively, and suppressed O. montana survival on rock squirrels by 70% to 94% from days 1 through 40. Results of this formative laboratory investigation sparked intensive field research on, and refinement of, fipronil baits for flea control, plague mitigation, wildlife conservation, and One Health objectives.

Plant essential oils are promising alternatives to synthetic larvicides, but their development is often limited by chemical variability, formulation challenges, and concerns regarding non-target toxicity. Baeckea frutescens, a widespread weed species, remains insufficiently characterized in terms of chemotypic diversity, stereochemical composition, and larvicidal selectivity. The essential oils were dominated by mono- and sesquiterpenoids, with p-cymene, 1,8-cineole, α- and β-pinene, α-humulene, caryophyllene oxide, and humulene epoxide II as major constituents. PCA and HCA revealed distinct chemotypic groups that may reflect temporal variation in essential oil composition. Chiral GC analysis showed pronounced enantiomeric excess for several terpenoids. In WHO-based larvicidal assays, free essential oils exhibited notable activity against Aedes aegypti (Linnaeus), Aedes albopictus (Skuse), and Culex quinquefasciatus Say (Diptera: Culicidae). The corresponding 24-h LC50 values ranged from 18.97 to 39.33 µg/mL, 10.60 to 13.11 µg/mL, and 19.79 to 45.62 µg/mL, respectively. Yeast encapsulation achieved a loading capacity of approximately 11.1% to 40.71% and retained larvicidal activity in acute assays. This study provides integrated chemotypic and enantiomeric insights into B. frutescens essential oil and demonstrates its acute larvicidal activity with preliminary indication of selectivity against multiple mosquito species using WHO-based protocols. The findings support the sustainable utilization of an underutilized weed species and provide a chemically informed basis for the development of sustainable botanical larvicides.

Incidence of tickborne diseases is increasing in the United States, with nearly half a million cases estimated to occur annually. The rising burden of tickborne disease in the United States underscores the need to investigate the presence and prevalence of tick species and associated pathogens. Southern Florida serves as an introductory point for non-native invasive reptiles, amphibians, and ectoparasites due to the region's international ports and tropical climate. At Zoo Miami, visitors are near exhibit animals and free-living invasive species, including cane toads and green iguanas. This study identified ticks removed from reptiles and amphibians at Zoo Miami and analyzed these ticks for bacteria in the order Rickettsiales. 309 ticks were collected over a 2-year period (October 2022 to November 2024; Amblyomma dissimile Koch, 1844 (266/309), Amblyomma rotundatum Koch, 1844 (41/309), and A. tuberculatum Marx, 1894 (2/309). Rickettsia spp. DNA (Rickettsiales: Rickettsiaceae) was identified in A. dissimile (4.14%) and A. rotundatum (4.88%), including a Rickettsia species similar to several strains of R. parkeri based on a portion of the ompA gene. Three ticks contained Anaplasmataceae DNA (Rickettsiales: Anaplasmataceae), including 1 Ehrlichia chaffeensis-positive A. rotundatum, and 1 A. dissimile containing E. canis-like DNA. This study represents the first report to jointly describe ticks and their rickettsial bacteria from Zoo Miami, including novel host records for A. dissimile and A. rotundatum. Paired with identification of an ehrlichial pathogen, these novel host associations highlight the importance of tick surveillance for pathogens of public health concern in zoos and other animal facilities in southern Florida.

Topical repellents are considered as valuable supplementary tools for reducing vector-borne disease transmission risk by preventing mosquito bites. Plant-based formulations have attracted growing interest as safer, more acceptable alternatives to synthetic repellents, yet evidence for their real-world effectiveness remains limited. This study evaluated the protective efficacy of two topical repellents, DEET and Vetiver essential oil (Vetiver E.O.) against Anopheles dirus Peyton & Harrison, a main malaria vector species, through semi-field system (SFS) trials. These tests were followed by a nine-month community-level randomized trial in Khun Han District, Sisaket Province, with concurrent social science evaluation. In the SFS trials, DEET reduced mosquito landing by 95.75% over 6 h, while Vetiver E.O. conferred moderate protection at 51.9%. Both products also reduced the percentage of blood-feeding, suggesting additional transmission-reducing potential beyond simple landing deterrence. At the community level, 457 participants were randomized into DEET, Vetiver E.O., and placebo groups. DEET participants demonstrated substantially higher product collection adherence and frequency of use than Vetiver E.O. or placebo participants. Participant-reported efficacy and acceptability ratings for Vetiver E.O. were comparable to the placebo group, suggesting that its biological activity was insufficient to generate a perceptible benefit under field conditions. Across all groups, participants predominantly applied repellents to clothing rather than exposed skin, likely attenuating real-world protective efficacy. These findings support the establishment of a minimum efficacy threshold under semi-field conditions before proceeding to community trials with candidate repellents and underscore the need to implement personal protection strategies that minimize the need for regular application by each individual.

Understanding how mosquito community, host use, and environmental drivers vary across landscapes is critical for predicting vector‑borne disease risk. Virginia spans multiple ecoregions and broad elevational gradient, yet statewide surveillance remains limited and concentrated near urban centers. To address surveillance gaps, we surveyed mosquitoes across four ecologically distinct sites in Virginia during 2022 to evaluate species diversity, bloodfeeding patterns, and environmental predictors of occurrence. Using CDC light traps, gravid traps, and supplemental aspiration, we collected 7,781 mosquitoes representing 34 species. Community composition varied significantly among sites: the Coastal Plain exhibited the greatest abundance and richness, while montane and urban sites supported lower but distinct assemblages. Several medically important and invasive species-including Aedes albopictus (Skuse), Aedes japonicus (Theobald), Culex pipiens/quinquefasciatus, Culiseta inornata (Williston), and the range-expanding Culex coronator (Dyar & Knab) and Culex nigripalpus (Theobald) were detected, providing new regional records beyond previously documented localities. Bloodmeal analysis from 18 specimens revealed predominantly mammalian feeding, with white‑tailed deer (Odocoileus virginianus [Zimmermann]) comprising over 80% of identified hosts across taxa. Avian and amphibian hosts occurred at lower frequencies, indicating diverse host-vector interactions relevant to enzootic transmission. Random forest models identified elevation and trap type as the strongest predictors of species-specific occurrence, with climatic factors exerting secondary effects. Together, these findings show that mosquito distribution and host selection in Virginia are shaped by interacting ecological and environmental drivers, underscoring the need for expanded, ecologically informed surveillance to improve assessments of vector‑borne disease risk in the region.

Mosquito abundance is strongly influenced by environmental conditions, yet species-specific responses to weather and land-cover variables remain insufficiently quantified in operational mosquito control programs. This study integrates multi-year surveillance data (2021-2024) with environmental predictors to identify drivers of mosquito abundance in a coastal landscape in Indian River County, Florida, USA with analyses focused on Culex nigripalpus, Aedes taeniorhynchus, and Aedes albopictus. Species-specific generalized linear mixed-effects models with a negative binomial distribution were used to relate mosquito abundance to lagged temperature, precipitation (including quadratic terms), and land-cover variables (wetlands, impervious surfaces, and marine lagoon habitats). Model performance was evaluated using temporal and spatial cross-validation. Distinct ecological responses were observed among species. Cx. nigripalpus was strongly associated with precipitation and wetland cover, with peak abundance at intermediate rainfall levels. Ae. taeniorhynchus showed strong positive associations with coastal and lagoon habitats and nonlinear responses to precipitation. In contrast, Ae. albopictus was primarily driven by temperature and impervious surface cover, with reduced abundance in wetland and coastal lagoon habitats. Spatial predictions revealed clear ecological partitioning among species. The results demonstrate that mosquito abundance in coastal landscapes is strongly structured by interactions among weather, land cover, and habitat type. Integrating environmental data with surveillance records offers a practical framework for predicting mosquito abundance and enables operational mosquito control programs to more precisely identify high-risk areas and optimal times for intervention, ultimately improving the efficiency and effectiveness of spatial and temporal targeting of vector control measures.

Species within the genus Cuterebra Clark, 1815 (Diptera: Oestridae: Cuterebrinae) are obligate parasites of rodents and other mammals during the larval stage, causing cutaneous myiasis. The internal larval anatomy of Cuterebra species remains unstudied, despite its potential utility for understanding their parasitic adaptations and for comparative studies with other Oestridae. The present study describes the internal larval anatomy of the species Cuterebra fontinella Clark, 1827 and Cuterebra americana (Fabricius, 1775), using micro-computed tomography-based virtual histological sections and 3-dimensional reconstructions. Both species show a broadly similar organization of the internal organs and tissues, with the digestive system being the main system within the hemocoel. The alimentary canal lacks gastric ceca and a crop; a condition shared with other Oestridae subfamilies, but which differs from the larvae of other Oestroidea families. The salivary glands are long and tubular, appearing morphologically distinct from those described in other Oestridae subfamilies thus far. The Malpighian tubules are uniformly thin and lack mineralized concretions, differing from the excretory organs of the oestrid species within the subfamily Oestrinae. The respiratory system shows little variation in relation to the basic tracheal scheme observed in the larvae of other cyclorrhaphous Diptera. Similarities and differences with the larvae of other Oestridae subfamilies and other Oestroidea families are discussed from a functional perspective, highlighting the value of nondestructive imaging techniques in comparative anatomical studies for contributing to a better understanding of the biology, evolution, and pathology of myiasis‑causing Diptera.

Psorophora mexicana (Bellardi) is a rare mosquito species with limited information on its taxonomy, geographic distribution, and ecological preferences. In Mexico, presence records are scarce and largely outdated, particularly in the Yucatan Peninsula. Here, we document the current distribution of Ps. mexicana based on collections conducted between 2017 and 2025 across 14 localities in Campeche, Quintana Roo, and Yucatan states, including the first confirmed record for Quintana Roo. Specimens were identified morphologically and genetically using the mitochondrial region cytochrome c oxidase I DNA barcoding. Generated sequences, representing the first records for Ps. mexicana in NCBI and BOLD Systems, and a phylogeny including 19 species of Psorophora was generated using a Bayesian phylogenetic framework. Environmental variables were explored using principal component analysis, revealing that Ps. mexicana currently occupies a broad spectrum of environmental conditions spanning multiple land-use types and gradients of habitat integrity. These results contrast clearly with previous Mexican records for this species, which have consistently characterized its distribution as restricted to anthropogenically disturbed habitats, predominantly urban environments, particularly in proximity to coastal regions. Our findings expand the known distribution of Ps. mexicana in southeastern Mexico and provide updated ecological and molecular insights into a poorly known species, highlighting its potential for increased human-mosquito contact in suitable environments.

Chemical interventions targeting mosquito vectors may unintentionally affect non-target beneficial mosquitoes occupying similar ecological niches. This study evaluated the susceptibility of the beneficial mosquito Toxorhynchites rutilus septentrionalis (Dyar & Knab) to commonly used mosquito control products at operational field rates and compared its responses with those of Aedes aegypti L. Two adulticides, permethrin-based Aqua-Kontrol 30-30 and bifenthrin-based Talstar P Professional, and 3 larvicides, Vectobac 12AS (Bacillus thuringiensis israelensis [Bti]), Natular DT (spinosad), and Altosid Pellets WSP (methoprene), were evaluated. Permethrin ultra-low-volume space spray caused complete mortality in both adult Ae. aegypti and Tx. r. septentrionalis within 1 h post-treatment. In contrast, the bifenthrin-based barrier treatment on foliage caused 100% mortality in Ae. aegypti up to 28 d after application, whereas Tx. r. septentrionalis adults survived despite exhibiting transient signs of pyrethroid-induced neurotoxicity. Larval susceptibility varied according to developmental stage and insecticide type. Bti caused rapid mortality in Ae. aegypti larvae, particularly, early instars of Tx. r. septentrionalis showed 50 to 92% mortality and late instars showed lower mortality (4 to 66%). Spinosad caused 84 to 100% mortality in both mosquito species within 72 h post-exposure, except in early instars of Tx. r. septentrionalis at the lowest concentration (14% mortality). Methoprene inhibited adult emergence in Ae. aegypti at the highest concentration but produced minimal effects on Tx. r. septentrionalis. These findings demonstrate that mosquito control products differ substantially in their non-target impacts on beneficial mosquitoes and highlight the importance of incorporating ecological risk assessments into integrated vector management programs.

This study evaluated the effectiveness of DNA barcoding, based on the mitochondrial COI gene, in delimiting species of the subfamily Phlebotominae from Maranhão, in addition to generating new molecular information and detecting possible cryptic species. Fragments of the COI gene were sequenced and integrated into public GenBank data. The species was delimited by means of species delimitation algorithms based on genetic distance (ABGD and ASAP) and phylogenetic gene trees (PTP), making it possible to identify patterns of cryptic diversity. In total, 54 consensus sequences were obtained, representing 23 species. Among these, Lutzomyia gomezi (Nitzulescu, 1931) and Psathyromyia punctigeniculata (Floch & Abonnenc, 1941) represent the first COI barcode sequences for these species in Brazil. BLAST and BOLD analysis coincided with morphological identification in most cases. The species Lu. sherlocki (Martins, Silva & Falcão, 1971) showed the greatest intraspecific distance and split into 2 clusters/MOTUs, suggesting the presence of distinct COI lineages or cryptic diversity. Unique clusters merging individuals of morphologically recognized species were also observed, such as Evandromyia lenti (Mangabeira, 1938)/Ev. carmelinoi (Ryan, Fraiha, Lainson & Shaw, 1986) and Psychodopygus complexus (Mangabeira, 1941)/Ps. wellcomei Fraiha, Shaw & Lainson, 1971. In view of these results, the need for further investigations using other molecular markers is evident, in order to expand the taxonomic resolution of these groups. Still, DNA barcoding (COI) proved to be efficient in delimiting most species and detecting possible cryptic species, while substantially expanding the molecular reference database for sand flies from Maranhão.

We present the first ectoparasite infestation values (prevalence, mean abundance, and mean intensity) in two bats, Leptonycteris yerbabuenae (Phyllostomidae) from Carmen Island, Baja California Sur (BCS) (N = 11) and Myotis californicus (Vespertilionidae) from Los Manzanos, Baja California (BC) (N = 6), Mexico. Twelve ectoparasitic species were identified belonging to Argasidae, Macronyssidae, Spinturnicidae, Trombiculidae, Leeuwenhoekiidae, Myobiidae, Nycteribiidae, Streblidae, and Cimicidae. Leptonycteris yerbabuenae exhibited high prevalence of bat flies (Nycterophilia coxata: 72.73%, Trichobius sphaeronotus: 45.45%) compared to mites and ticks, while mites and bat bugs of M. californicus showed high prevalence (Macronyssus crosbyi: 83.33%, Cimex pilosellus: 66.67%). Leptotrombidium californicum, found on M. californicus, represents a new record for BC and the country, and showed the highest mean abundance (19.17 ± 46.95) and mean intensity (115). Nycterophilia coxata presented higher prevalence and abundance than mite Periglischrus paracaligus, and higher intensity than T. sphaeronotus, consistent with values of previous studies. The high mite prevalence of M. californicus (Cryptonyssus desultorius: 50% and M. crosbyi), contrasts with the low prevalence reported for populations from southern California and Oregon, USA (1% and 2%). The two bat species did not share ectoparasite taxa; however, larger sample sizes and appropriate statistical analyses are needed to test potential biogeographical and host specificity patterns. Therefore, infestation values reported in this study should be interpreted with caution until future studies support or challenge these inferences. Presentamos los primeros valores de infestación ectoparasitaria (prevalencia, abundancia promedio e intensidad promedio) en dos murciélagos: Leptonycteris yerbabuenae (Phyllostomidae) de la Isla del Carmen, Baja California Sur (BCS) (N = 11) y Myotis californicus (Vespertilionidae) de Los Manzanos, Baja California (BC) (N = 6), México. Se identificaron 12 especies ectoparásitas pertenecientes a las familias Argasidae, Macronyssidae, Spinturnicidae, Trombiculidae, Leeuwenhoekiidae, Myobiidae, Nycteribiidae, Streblidae y Cimicidae. Leptonycteris yerbabuenae presentó una alta prevalencia de moscas parásitas (Nycterophilia coxata: 72.73%, Trichobius sphaeronotus: 45.45%) en comparación con ácaros y garrapatas; mientras que ácaros y chinches de M. californicus mostraron una alta prevalencia (Macronyssus crosbyi: 83.33%, Cimex pilosellus: 66.67%). Leptotrombidium californicum, encontrado en M. californicus, representa un nuevo registro para BC y el país, y mostró la mayor abundancia promedio (19.17 ± 46.95) e intensidad promedio (115). Nycterophilia coxata presentó mayor prevalencia y abundancia que el ácaro Periglischrus paracaligus, y mayor intensidad que T. sphaeronotus, consistente con valores de estudios previos. La alta prevalencia de M. californicus (Cryptonyssus desultorius: 50% y M. crosbyi) contrasta con la baja prevalencia registrada para poblaciones del sur de California y Oregón, EE. UU. (1% y 2%). Las dos especies de murciélagos no compartieron taxones ectoparasitarios; sin embargo, se requieren mayores tamaños de muestra y análisis estadísticos adecuados para poner a prueba posibles patrones biogeográficos y de especificidad hospedatoria. Por tanto, los valores de infestación encontrados en este estudio deben interpretarse con cautela hasta que futuros estudios confirmen o contrasten estos hallazgos.

Equine hepacivirus (EqHV) is a hepatotropic virus, closely related to human hepatitis C virus (HCV), that can cause acute or chronic infection in horses. As with HCV, transmission is thought to occur primarily through parenteral, particularly blood-borne, routes. Vertical transmission from mare to foal has been reported but appears to be uncommon. The high seroprevalence in horse populations and the occurrence of infection in isolated horses indicate efficient horizontal transmission routes exist. One such possibility is biological or mechanical transmission by arthropods, such as mosquitoes, stable flies, or ticks. Here, we conducted 2 complementary studies to evaluate the possible role of mosquitoes as EqHV biological vectors. In the laboratory, we orally exposed Aedes albopictus (Skuse) females to EqHV through artificial bloodfeeding with blood collected from 2 chronically infected horses. Mosquito samples (body, legs, and saliva) were collected at multiple time points post-exposure and tested for EqHV RNA by molecular assays. In the field, 2,138 mosquitoes were collected from New York and Florida, United States, and screened for EqHV RNA. No EqHV RNA was detected in any samples from the laboratory experiment or among field-collected mosquitoes. These findings indicate that the Ae. albopictus strain evaluated here is unlikely to serve as a biological vector of EqHV and corroborate previous negative findings in field-collected mosquitoes. Nevertheless, low infection rates may have gone undetected. Laboratory studies of additional horse-feeding mosquito species and expanded field collections in EqHV-endemic regions are needed to further clarify any potential role for mosquitoes in EqHV transmission.