Brazil is endemic for both visceral (VL) and cutaneous (CL) clinical forms of leishmaniasis, poverty-associated diseases with worldwide distribution. Leishmania parasites are the etiological agents of leishmaniases, which are transmitted to humans through the bites of infected phlebotomine sand flies. From 2018 to 2023, 15 cases of VL and 129 cases of CL were reported in Téofilo Otoni, an important economic center in the Brazilian state of Minas Gerais. Owing to the lack of data on the entomological fauna, the present study aimed to clarify this main aspect of leishmaniasis. From May, 2021 to April, 2023, entomological captures were performed monthly in ten neighborhoods in Teófilo Otoni. The influence of bioclimatic variables on insect populations was evaluated, and natural infection by Leishmania spp. was investigated using molecular methods. A total of 306 specimens of 12 species of phlebotomine sand fly were collected. The majority (91.6%) were proven or putative vectors of leishmaniasis agents. The population of insects tended to increase during the cooler and drier months. Although Leishmania infection was not detected in any of the samples, the presence of vectors provides conditions for the maintenance and expansion of the transmission cycle of leishmaniasis in Teófilo Otoni.

Mosquitoes (Diptera: Culicidae) and the pathogens they transmit represent a threat to human and animal health. Low-cost and effective surveillance methods are necessary to enable sustainable monitoring of mosquito distributions, diversity, and human interactions. This study examined the use of iNaturalist, an online, community-populated biodiversity recording database, for passive mosquito surveillance in the United Kingdom (UK) and Ireland, countries under threat from the introduction of invasive mosquitoes and emerging mosquito-borne diseases. The Mozzie Monitors UK & Ireland iNaturalist project was established to collate mosquito observations in these countries. Data were compared with existing long-term mosquito UK datasets to assess representativeness of seasonal and distribution trends in citizen scientist-recorded observations. The project collected 738 observations with the majority recorded 2020-2022. Records were primarily associated with urban areas, with the most common species Culex pipiens and Culiseta annulata significantly more likely to be observed in urban areas than other species. Analysis of images uploaded to the iNaturalist project also provided insights into human-biting behavior. Our analyses indicate that iNaturalist provides species composition, seasonal occurrence, and distribution figures consistent with existing datasets and is therefore a useful surveillance tool for recording information on human interactions with mosquitoes and monitoring species of concern.

Land cover is recognized as an important determinant of mosquito community assemblages and pathogen transmission, but few studies have investigated the role of land cover in populations of La Crosse virus (LACV) vectors. La Crosse virus is a zoonotic disease primarily maintained by native Aedes triseriatus, with accessory transmission by invasive vectors Ae. albopictus and Ae. japonicus. The objective of this study was to investigate the association between land cover composition and the egg abundances of LACV vectors in a city with endemic LACV transmission. Oviposition cups were deployed at sites ranging from recreational forests to urban areas. Mixed-effects regression models were used to test the relationships between land cover composition and species abundances. Sites characterized by large percentages of impervious and built surfaces were dominated by Ae. albopictus, but Ae. triseriatus was the most abundant species in forested areas. Aedes japonicus was rare at all sites, but its presence was associated with higher percentages of forested land. These results indicate that forested areas may allow Ae. triseriatus to maintain large populations near urban areas that are dominated by Ae. albopictus. Further research should explore the potential for these land cover-dependent population dynamics to influence LACV transmission cycles.

Flea-borne diseases are endemic in Texas, U.S.A., with an increasing incidence of flea-borne typhus and cat scratch disease. Knowledge of flea natural history could provide information to protect public health, yet many knowledge gaps remain outside of plague-endemic regions. Our objective was to characterize seasonal activity patterns of fleas on common mammalian wildlife species and test fleas and wildlife for Rickettsia and Bartonella pathogens. We performed one year of monthly trapping for rodents and medium-sized mammals in a national forest with high recreational use and urban encroachment in East Texas. From 90 mammal captures representing seven species, 101 fleas were collected representing Polygenis spp., Ctenocephalides felis, and Orchopeas species. Virginia opossums (Didelphis virginianus) hosted 99% of the collected fleas (100 fleas) and a single flea was on an eastern woodrat (Neotoma floridana). Flea infestation prevalence of opossums was 79% (23/29). Mean flea abundance was 4.39 fleas, with intensity peaking in spring. One cat flea removed from an opossum was positive for Bartonella henselae. Furthermore, we identified tissue or blood of four raccoons (Procyon lotor) and one golden mouse (Ochrotomys nuttalli) positive for Rickettsia amblyommatis. These findings provide an ecological basis for the maintenance of vectors and pathogens from sylvatic settings.

The Capivari-Monos Environmental Protection Area (EPA) is located in the southern part of the São Paulo city Green Belt. Since the 1950s, this region has been affected by uncontrolled urban sprawl, resulting in a change in the ecological habits of some vector mosquitoes. Over the last two decades, cases of autochthonous bromeliad malaria associated with the presence of anopheline mosquitoes in the EPA have been recorded. Anopheles cruzii, the primary vector of plasmodia in the region, is abundant and found naturally infected with both Plasmodium vivax and Plasmodium malariae. In light of this, the present study sought to update the catalog of mosquito fauna in this EPA, analyze mosquito diversity among sites with different degrees of conservation and compare species using different collection techniques. Field collections were carried out from March, 2015 to April, 2017. A total of 20,755 specimens were collected, distributed in 106 different taxa representing 16 genera. Analysis of the diversity among the sites based on the Shannon and Simpson indices showed that the most preserved of them had the lowest indices because of the dominance of An. cruzii. The results highlight the increase in the number of different taxa collected as different mosquito collection techniques were included, confirming the importance of using several strategies to ensure adequate sampling of a local mosquito fauna when exploring a greater number of ecotopes. Furthermore, the survey produced the most recent and complete list of mosquito species in the Capivari-Monos EPA, a refuge and shelter for native and introduced mosquito species where new biocenoses, including pathogens, vertebrate hosts, and vectors can form, allowing zoonotic outbreaks in the local human population to occur.

Spatial and temporal differences in the relative abundance of arthropod vectors are important factors that influence the risk of disease for mammalian hosts. Seasonal changes in the diversity and abundance of fleas (Siphonaptera) in Richardson's ground squirrel (Urocitellus richardsonii) burrows were studied at two sites in central Saskatchewan. A total of 225 fleas (151 at an urban site and 74 at a rural site) were collected. Flea prevalence differed among seasons at the urban site but not at the rural site. Of the nine flea species detected (eight at the urban site and six at the rural site), Oropsylla rupestris, O. bruneri, O. labis, O. tuberculata, and Aetheca wagneri are vectors of Yersinia pestis, the causative agent of plague. The presence and abundance of some fleas differed between sites and seasons. Neopsylla inopina and O. rupestris were the most abundant species at the urban site during the spring and summer, respectively, while O. bruneri was the most abundant species at the rural site. Our findings may have implications for the management of the black-tailed prairie dogs (Cynomys ludovicianus) in southwestern Saskatchewan because they coexist with U. richardsonii, are hosts for Oropsylla, and are at great risk of plague exposure/infection.

Wingbeat frequency may serve as a distinctive physical signature for identifying mosquito species. However, variation in wingbeat frequency within species may compromise reliability of wingbeat frequency-based mosquito identification. We examined the impact of mosquito density (number of females), time of day (day or night), gravid status, and age (days post-emergence) on the wingbeat frequency of three important vector mosquito species using infrared optical sensors. Wingbeat frequency of Culex quinquefasciatus was significantly higher (6.2% and 9.5%) for single females compared to groups of five and ten females, respectively, and 9.4% higher during the daytime compared to nighttime. Wingbeat frequency was also significantly higher for gravid Cx. quinquefasciatus (9.4%) and Aedes aegypti (1.4%) than nongravid conspecifics. Within a short age range (five to seven days post-emergence), wingbeat in Cx. quinquefasciatus did not vary significantly. Our results highlight that both extrinsic (density and time of day) and intrinsic (gravid status) factors contribute to wingbeat variation, potentially posing challenges for development of wingbeat profile libraries and the classification of unknown specimens. Traps that aim to use wingbeat frequency and target specific cohorts of the population (i.e., host-seeking or gravid females) will need to account for differences in wingbeat frequency due to multiple factors.

The stridulation in the subfamily Triatominae has been identified as a means of communication between species, produced by the friction of the proboscis on the prosternal stridulatory groove. Despite its biological significance, this phenomenon remains understudied, with the signal's production seemingly contingent upon the morphology of the stridulatory groove. In this study, we examined the morphology of stridulatory grooves in females and males of five species and two subspecies of Mexican triatomines using morphometric and scanning electron microscopical analysis. Our findings reveal that all analyzed species exhibit triangular-shaped stridulatory grooves with parallel ridges covering the entire groove, bordered on each side, and covered with setae. Surprisingly, we observed noticeable differences in the number of ridges and inter-ridge distance between the species Triatoma lecticularia and Triatoma rubida (p < 0.001 and p < 0.009, respectively), indicating sexual dimorphism in this aspect, a phenomenon not previously reported in the morphology of this structure. Our findings shed light on the intricate morphology of the stridulatory groove in Mexican triatomines, suggesting potential implications for their behavior and intra-specific communication.