BioOne.org will be down briefly for maintenance on 12 February 2025 between 18:00-21:00 Pacific Time US. We apologize for any inconvenience.
Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact helpdesk@bioone.org with any questions.
Due to economic and food security concerns, veterinary entomology has traditionally focused on livestock pests and ectoparasites. However, recognizing the significant environmental changes of the Anthropocene era, there is a need to broaden the scope to include pests and ectoparasites of wildlife.This review highlights key studies from 2023 that go beyond the barnyard and represent this expanded focus. Key areas explored include the development and application of unique methodologies, the impact of arthropods on behavior, and the effects of anthropogenic and environmental influences on pests, ectoparasites, and hosts. By adopting a broader perspective, veterinary entomologists can develop new collaborations and better understand the complex interactions between pests, ectoparasites, and a diverse array of nonhuman vertebrates.This comprehensive understanding is essential for advancing global health and biodiversity conservation.
Organophosphate insecticides are widely used for adult mosquito control. Although proven effective in reducing mosquito populations and limiting arbovirus transmission, public concern exists regarding potential human health effects associated with organophosphate exposure. The aim of this scoping review was to describe any reported human health conditions associated with organophosphates during their use for adult mosquito control in the United States and Canada. Original peer-reviewed articles published in English language journals from 1 January 2000 to 22 May 2024, were obtained by searching from the databases MEDLINE, EMBASE, Agricultural & Environmental Science Collection, CAB Abstracts, and Scopus. The search identified 6,154 screened articles. Following an independent review, 10 studies were identified that described human health conditions associated with organophosphate exposure during adult mosquito control applications. Of the 10 included studies, only two articles were published within the last 11 years (2013 to 22 May 2024). Three types of study design were represented in the included studies: cohort (n = 5), case study (n = 1), and risk assessment (n = 4). The included studies could not determine causality between exposure to adulticides and development of illness or adverse impacts. Exposure to organophosphates did not contribute to an observed increase in metabolic toxicity, hospitalization rates, or self-reported symptoms and exposure. The available and limited evidence indicates that organophosphates can be used safely to control nuisance mosquitoes or mosquitoes that transmit arboviruses. Continued research regarding the human health effects associated with organophosphate applications for adult mosquito control could help evaluate the basis of the public's concerns and inform public health decision-making.
An arthropod's vectorial capacity summarizes its disease transmission potential. Life-history traits, such as fecundity or survival, and behavioral traits, such as locomotor activity, host-seeking and feeding behavior, are important components of vectorial capacity. Studies have shown that mosquito-borne pathogens may alter important vectorial capacity traits of their mosquito vectors, thus directly impacting their transmission and epidemic potential. Here, we compile and discuss the evidence supporting dengue-mediated changes in the yellow fever mosquito Aedes aegypti (L.), its primary vector, and evaluate whether the observed effects represent an evolved trait manipulation with epidemiological implications. Dengue infection appears to manipulate essential traits that facilitate vector–host contact, such as locomotor activity, host-seeking, and feeding behavior, but the underlying mechanisms are still not understood. Conversely, life-history traits relevant to vector population dynamics, such as survival, oviposition, and fecundity, appear to be negatively impacted by dengue virus. Overall, any detrimental effects on life-history traits may be a negligible cost derived from the virulence that dengue has evolved to facilitate its transmission by manipulating Ae. aegypti behavior and feeding performance. However, methodological disparities among studies render comparisons difficult and limit the ability to reach well-supported conclusions. This highlights the need for more standardized methods for the research into changes in virus-mediated traits. Eventually, we argue that the effects on life-history traits and behavior outlined here must be considered when assessing the epidemiological impact of dengue or other arbovirus–vector–host interactions.
Mosquitoes of the Culex (Cx.) pipiens complex are vectors of severe diseases including West Nile fever by West Nile virus, Japanese encephalitis by Japanese encephalitis virus, and Lymphatic filariasis by filarial nematode Wuchereria bancrofti. As a major portion of mosquito immune system, the Toll pathway implicates in response against infections of mosquito-borne pathogens and biocontrol agents. The genetic diversity of immune-related molecules is expected to be a feasible and effective introduction to expand our knowledge of the mosquito-microbe interplay. However, a comprehensive description is currently lacking regarding the genetic characteristic of the Toll pathway molecules in Cx. pipiens complex mosquitoes. In the present study, genetic changes in Cx. pipiens complex MyD88 (Myeloid differentiation primary response protein 88) were analyzed as a precedent for theToll pathway molecules in this taxon. MyD88 is a critical adaptor of the pathway transducing signals from TIR-containing receptors to downstream death domain-containing molecules. Our results revealed that adaptive selection has influenced the genetic changes of the molecule, giving rise to acceleration of diversity at a number of amino acid sites.The adaptively selected sites lie in the death domain, intermediate domain, and C-terminal extension.The characteristics of the genetic changes shed insights into the prominent molecular-level structural basis and the involvement strategy of the adaptor in the arms race against exogenous challenges. This finding would be beneficial for further exploration and deeper understanding of the mosquitoes' vectorial capacity and facilitating the effectiveness and sustainability of the biocontrol agents.
Mosquitoes threaten over half of the world's population through vectored diseases such as malaria, zika, yellow fever, dengue, and chikungunya. Mosquitoes have a highly developed olfactory system attuned to chemotaxis relating to host-seeking, mating, and oviposition behavior. In this study, we aimed to determine the spatial efficacy of 2 plant-based repellent blends (Blend3 and Blend4 that had previously been found to successfully repel Aedes, Anopheles and Culex mosquitoes in wind tunnel assays) in excluding Aedes aegypti from the window entry. A new cage system was developed for parallel “no-choice” and “choice” olfactometric assays. In the no-choice trial, Blends 3 and 4, as well as commercial products (N, N-diethyl-3-methylbenzamide, p-menthane-3,8-diol [PMD], 3-(N-n-butyl-N-acetyl)-amino-propionic acid ethyl ester, and 2-(2-hydroxyethyl)-1-methylpropylstyrene 1-piperidine carboxylate), were adsorbed into filter papers of different sizes and placed in a window created between 2 attached bug dorms. Then, the number of mosquitoes entering the window was counted through a 6-min period. In choice olfactometric assays, Blends 3, 4, and PMD were adsorbed into filter paper and the number of mosquitoes moving away from Blend 3 and PMD were compared. No-choice assays showed that Blend3 (P < 0.001) and Blend4 (P = 0.0012) were more repellent than the best commercial product PMD. Additionally, while Blend 4 was significantly more repellent than Blend 3 (P = 0.012) in the choice assay, overall, these 2 blends show promise as new repellents for the spatial exclusion of Aedes aegypti from window entry alone or as part of a “push-pull” strategy.
Phormia regina (Meigen, 1826; Diptera: Calliphoridae) is a Holarctic species that rapidly colonizes carcasses and has been used as an indicator for determining the minimum postmortem interval. However, studies using morphological methods to estimate the intrapuparial age of P. regina are lacking. In this study, morphological changes within the puparium were observed under a stereomicroscope at 7 constant temperatures ranging from 16 °C to 34 °C.The intrapuparial period was categorized into 12 substages. Morphological indicators, including compound eyes, mouthparts, antennae, thorax, legs, wings, and abdomen, were recorded in detail. The observed morphological changes were divided into 6–10 substages, and the duration of each substage was also recorded in detail.The results of this study provide primary data for using the intrapuparial morphology of P. regina when pupae are collected at a crime scene and estimating the minimum postmortem interval.
Questionnaires and clinical observations are significant components of human and veterinary epidemiology surveys, providing a comprehensive prognosis of the occurrence and prevalence of diseases. The information compiled by these two survey methods is equally important for establishing an epidemiological surveillance system for disease outbreak management. This review summarizes 57 previous surveys, including questionnaires and clinical observations on sheep myiasis globally from 1976 to 2023, with an emphasis on their methodologies and areas of findings. Overall, this review establishes a baseline understanding of the essential entomological and veterinary aspects required for designing questionnaires and clinical observation surveys on sheep myiasis. Additionally, it provides guidance for implementing future study protocols and proposes a farmer-based approach that integrates these techniques to achieve improved outcomes in mitigating sheep myiasis.
Soft ticks (Argasidae) of the subgenus Pavlovskyella Pospelova-Shtrom are worldwide distributed parasites of medical importance. However, the systematics of the subgenus are currently under debate because genetic data shows that the group is paraphyletic. Meanwhile, species of Pavlovskyella continue to be discovered. In this study a novel species of the subgenus is described from specimens collected on a fox in central Chile. The larva of this new species differentiates from other Pavlovskyella spp. by having the following combination of characters: subpyriform dorsal plate; 15 pairs of setae, 7 anterolateral, 3 central, and 5 posterolateral, and hypostome with denticles in the distal third. Nymphs and adults of the species lack cheeks, eyes or bulging structures on the flank, but exhibit dorsoventral grooves, and humps on tarsi I, II, and III. Moreover, a patch of glabrous integument appears on the distal portion of coxal folds. A phylogenetic analysis using the mitogenome indicates a monophyletic group composed by Ornithodoros (Pavlovskyella) brasiliensis Aragão, Ornithodoros (Pavlovskyella) furcosus Neumann, Ornithodoros (Pavlovskyella) improvisus Muñoz-Leal & Venzal, and Ornithodoros (Pavlovskyella) rostratus Aragão. Interestingly, a phylogeny using 18S–28S rDNA sequences shows that South American Pavlovskyella spp. are paraphyletic, as depicted in previous studies. Adding species of the subgenus from the Neotropical region to phylogenetic analyses could aid to solve this paraphyly. Furthermore, this is the fifth species of Pavlovskyella described in South America, and the second in Chile.
Anopheles baileyi species D of the Baileyi Complex, subgenus Anopheles (Diptera: Culicidae) in Thailand is diagnosed and formally named An. inthanonensis Somboon & Harbach, n. sp. Morphological characters of the adults, and the pupal and larval stages with their chaetotaxy, are provided and compared with other species of the complex. Phylogenetic analysis of COI sequences revealed that An. inthanonensis appears to be more closely related to An. monticola in Bhutan and China than it is to other members of the Baileyi Complex.
An extensive mosquito survey was carried out in Hong Kong from September to October 2022, employing a variety of collection methods. Specimens were identified using a combination of morphology and mitochondrial cytochrome C oxidase subunit 1 (COI) barcode sequences. Twenty-nine species, including three new records, i.e., Culex bicornutus (Theobald), Culex cinctellus Edwards, and Lutzia chiangmaiensis Somboon & Harbach, were collected. Phylogenetic analysis of COI sequences of Culex annulusTheobald and Culex vishnuiTheobald collected in Hong Kong and elsewhere revealed that the sequences of the two nominal species are genetically very similar and are included in the same clade. Consequently, the synonymy of Cx. annulus with Cx. vishnui is reinstated. Lutzia halifaxii (Theobald) is removed from the list of species in Hong Kong and is replaced with Lutzia vorax Edwards, the identification of which is confirmed in the present study. The record of Culex spiculothorax Bram recorded in Hong Kong is replaced with the senior synonym Culex sasai Kano, Nitahara & Awaya. The occurrence of Anopheles fluviatilis James and Aedes aegypti (Linnaeus) is discussed. Finally, an updated checklist of the mosquitoes of Hong Kong, which now includes 76 species representing 14 genera, is provided, with notation of those species that vector pathogens of human diseases.
Phlebotomine sand flies are insects of notorious importance in public health, mainly due to their involvement in the transmission of Leishmania protozoa. Their flight activity occurs predominantly in the twilight/night period, being stimulated mainly by the need to search for food and reproduction. Despite being naturally wild, some species are able to invade anthropized environments. Present work aimed to assess the nocturnal activity and forestry-urban dispersal of phlebotomine sand flies from an ecotourism park in Belém, Amazonian Brazil. The study area comprised a horizontal transect, extending from a forest park to the neighboring urban environment, in Belém. Sampling was conducted with night-operating light traps. Nocturnal activity was assessed through time-set captures with a collection bottle rotator in the forest environment. Dispersal was assessed through captures carried out along the transect, starting from the forest edge (0 m), extending to the urban environment (50–200 m), phlebotomine sand flies were identified. Abundance, richness, diversity, and sampling sufficiency were estimated. Fourteen species were recorded in the surveyed environments, with Nyssomyia antunesi, Trichophoromyia brachipyga, and Trichophoromyia ubiquitalis being the most abundant. Nocturnal activity behavior of Ny. antunesi occurred between 8 PM and 4 AM while that of Th. brachipyga and Th. ubiquitalis occurred between 2 AM and 6 AM. In the urban environment, the 150 m site presented the highest abundance. Bichromomyia flaviscutellata was sampled in all sites. Gravid females of Pressatia choti and Bi. flaviscutellata were sampled in the urban environment. Putative differential activity between the species herein assessed and their urban dispersal observed are worthy of note, adding data for supporting vector surveillance at a local scale.
Numerous tick species are undergoing significant range expansion in Canada, including several Dermacentor spp Koch (Acari: Ixodidae). With the recent description of Dermacentor similis Lado in the western United States, additional research is required to determine the current range of this species. Five hundred ninety-eight Dermacentor spp. were collected from companion animals in the western Canadian provinces of British Columbia, Alberta, and Saskatchewan. Ticks were morphologically identified to species, followed by PCR and gel electrophoresis of the ITS-2 partial gene target (n = 595). Ninety-seven percent (n = 579/595) generated valid banding patterns. The banding pattern for the majority (74%, n = 206/278) of Dermacentor spp. from southern British Columbia was consistent with D. variabilis (Say), while 26% (n = 72/278) was consistent with D. andersoni Stiles. For samples from Alberta, 38% (n = 3/8) had banding patterns consistent with D. variabilis and 63% (n = 5/8) with D. andersoni. All (n = 293) ticks from Saskatchewan had banding patterns consistent with D. variabilis. After the description of D. similis was published, DNA sequencing of mitochondrial (16S rDNA gene, COI gene) and nuclear (ITS-2) markers was used to confirm the identity of 40 samples. Twenty-seven samples that had banding patterns consistent with D. variabilis from British Columbia were confirmed to be D. similis. One sample from Alberta and five from Saskatchewan were confirmed to be D. variabilis and seven samples from British Columbia were D. andersoni. The ITS-2 amplicons were not useful for differentiating between D. variabilis and D. similis. These results provide evidence of D. similis in western Canada and highlight that sequences of the mitochondrial genes are effective for distinguishing D. andersoni, D. variabilis, and D. similis.
VECTOR CONTROL, PEST MANAGEMENT, RESISTANCE, REPELLENTS
Julián Felipe Porras-Villamil, Immo A. Hansen, Lee A. Uranga, Matthew Pinch, Coby Schal, Sandra Sáez-Durán, Rubén Bueno-Marí, María Trelis, Màrius V. Fuentes, Sudip Gaire, Alvaro Romero
In recent decades, the common and the tropical bed bugs have experienced a resurgence in many parts of the world. The evolution of insecticide resistance in bed bug populations is considered a significant factor contributing to this resurgence. We analyzed samples of Cimex lectularius L. and Cimex hemipterus (F.) from Europe (Spain 41, Switzerland 2, the Czech Republic 1), Asia (Hong Kong 34), North America (USA 14, Mexico 3), and South America (Colombia 3) to assess the prevalence and mechanisms of insecticide resistance. We identified specimens morphologically and barcoded them by sequencing the mitochondrial Cytochrome c oxidase subunit I (COI) and the 16S ribosomal RNA (16S rRNA) genes. Additionally, we screened segments of the voltage-gated sodium channel (VGSC) and the nicotinic acetylcholine receptor (nAChR) genes for point mutations associated with insecticide resistance and measured the activity of detoxifying enzymes. All samples from North America and Europe were identified as C. lectularius, whereas specimens from Hong Kong were C. hemipterus. Out of 64 C. lectularius samples tested for knockdown resistance (kdr) mutations, 90.6% contained at least 1 known mutation. All 35 C. hemipterus samples exhibited kdr mutations. A new mutation was identified in the pyrethroid target site in both common (F1524C) and tropical (F1450C) bed bugs. No resistance-associated mutations in the nAChR gene were found. Several populations that exhibited kdr mutations also showed elevated activity of detoxifying enzymes. The high frequency of kdr-associated mutations in bed bug populations from Spain and Hong Kong limits the efficacy of pyrethroids for their control.
Eva A. Buckner, Ana L. Romero-Weaver, Sierra M. Schluep, Shawna K. Bellamy, Rebecca A. Zimler, Natalie L. Kendziorski, Daviela Ramirez, Shelley A. Whitehead
Culex quinquefasciatus is an important mosquito vector responsible for the transmission of filarial worms, arthropod-borne viruses like Oropouche, St. Louis encephalitis, and West Nile and protozoans that cause avian malaria. Due to insecticide resistance documented in Cx. quinquefasciatus populations worldwide, integrated vector management programs can benefit from new strategies to control this species. The In2Care Mosquito Station (In2Care station), a commercially available dissemination station containing pyriproxyfen (PPF) and Beauveria bassiana spores, has been shown to be effective against skip-ovipositing Aedes aegypti and Aedes albopictus in previously conducted semifield and field trials.To determine the potential of Cx. quinquefasciatus adult females to autodisseminate PPF and if the In2Care station could be used for Cx. quinquefasciatus control, we assessed its efficacy in a semifield setting against wild Cx. quinquefasciatus. We found that the In2Care station was attractive to gravid Cx. quinquefasciatus females, with a significantly higher percentage of egg rafts laid in the In2Care station compared to alternative ovipots. Adult females successfully autodisseminated PPF from the In2Care station to surrounding ovipots, leading to a significant increase in mosquito emergence inhibition. Additionally, adult Cx. quinquefasciatus exposure to B. bassiana spores significantly reduced mosquito survivorship. These results suggest that the In2Care station may be effective against Cx. quinquefasciatus in addition to Ae. aegypti and Ae. albopictus. Additional field evaluations are needed to assess impacts at the population level.
Members of the Anopheles Hyrcanus Group, Culex pipiens complex, and Culex tritaeniorhynchus are prevalent vector species in the Republic of Korea (ROK), transmitting Plasmodium vivax and various arboviruses. Extensive use of insecticides to control these mosquitoes has led to insecticide resistance. In this study, we monitored 3 target site mutations associated with insecticide resistance (kdr for pyrethroid resistance, ace1 for organophosphate resistance, and rdl for phenylpyrazole resistance) in these mosquito groups over four consecutive years to understand the seasonal dynamics of resistance in different areas with distinct ecological characteristics. In the Anopheles Hyrcanus Group, the frequencies of kdr and ace1 mutations exhibited seasonal fluctuations in an urban-rural complex area (Humphreys US Army Garrison) (hereafter Humphreys), suggesting an overwintering fitness cost, whereas the rdl mutation frequencies remained constant at nearly saturated levels. These patterns were less clear in rural areas (the demilitarized zone separating Korea), indicating area-specific profiles related to different insecticide usage patterns. The kdr and rdl mutation frequencies associated with the Cx. pipiens complex were relatively constant, but varied by the collection area, with higher rdl frequency in Humphreys and higher kdr frequency in Yongsan, a metropolitan area, suggesting different selection pressures. Overall resistance mutation frequencies were highest in Cx. tritaeniorhynchus, with ace1 and rdl mutations being seasonally saturated, while the kdr mutation frequency varied over time. Our findings demonstrate species- or group-specific seasonal and regional dynamic patterns of insecticide resistance, presenting the need for targeted control strategies and further improving the management of mosquito-borne diseases in the ROK.
Blacklegged ticks (Ixodes scapularis) are the most medically and economically important vectors in North America. Each of their 3 life stages requires a blood meal from one of many potential host species, during which they can acquire or transmit pathogens. Host species, however, vary tremendously in their quality for ticks, as measured by differences in feeding and molting success.There should be clear fitness benefits for ticks that preferentially feed upon high-quality hosts (e.g., white-footed mice, Peromyscus leucopus), or at least avoid feeding on very low-quality hosts (e.g., Virginia opossums, Didelphis virginiana). Indeed, laboratory experiments have found some evidence of host preferences in I. scapularis; but these involve presenting ticks with hosts simultaneously and measuring movement towards hosts on a horizontal plane. In nature, however, host-seeking ticks encounter hosts sequentially and their movements are principally in a vertical plane. Here, we present the results of a study in which we measured the vertical movements of host-seeking juvenile blacklegged ticks before and after a host (P. leucopus, Tamias striatus, Sciurus carolinensis, or D. virginiana) was present, and whether the strength of their responses varies with host quality. We found ticks did not measurably alter the speed of their vertical movement in the presence of any hosts, regardless of host quality. Both larvae and nymphs quested slightly higher in the presence of hosts, but this did not vary by host species.These results call into question the existence of active host preferences, at least in this stage of the host-seeking process.
Flávia C.M. Collere, Larissa D.R. Ferrari, Aamir M. Osman, Ahmed A. Hassan-Kadle, Mohamed A. Shair, Vanessa S. Coradi, Abdalla M. Ibrahim, Thiago F. Martins, Abdulkarim A. Yusuf, Ivan R. de Barros-Filho, Rogério R. Lange, Marcos R. André, Thállitha S.W.J. Vieira, Rosangela Z. Machado, Rafael F.C. Vieira
Hemotropic mycoplasmas (hemoplasmas) are small pleomorphic bacteria that parasitize the surface of red blood cells of mammals. Hemoplasmas have been described in different species from the Camelidae Family, such as llamas and alpacas (South American camelids), but data on dromedary camels (Camelus dromedarius) are limited to a few reports. Somalia has one of the world's largest dromedary camel populations, and studies on hemoplasmas and tick-borne pathogens are lacking. Accordingly, this study aimed to screen dromedaries from Somalia for hemoplasmas by PCR-based assays. A total of 155 dromedary camel blood samples from 2 different areas of Mogadishu (n = 104) and the Lower Shabelle Region (n = 51) of the country were collected. All blood DNA samples were screened for hemoplasmas using a SYBR Green Universal Real-Time PCR (qPCR), nested PCR (nPCR), and conventional PCR (cPCR) assays targeting the 16S rRNA gene of hemoplasmas. Five out of 155 animals (3.23%; 95% confidence interval [CI]: 1.39–7.33%) were positive for hemoplasmas. A total of 346 (228 M, 117 F, and 1 nymph) ticks were collected from 79/155 (50.9%; 95% CI: 42.8–59.1%) dromedary camels with a mean of 4.4 ticks per animal. Ticks were identified as Rhipicephalus pulchellus (174/346; 50.3%), Hyalomma dromedarii (103/346; 29.8%), Hyalomma rufipes (35/346; 10.1%), Hyalomma marginatum (16/346; 4.6%), Rhipicephalus humeralis (14/346; 4.0%), Amblyomma lepidum (2/346; 0.6%), Amblyomma gemma (1/346; 0.3%), and Ornithodoros sp. (1/185; 0.5). This is the first study on the molecular screening for hemoplasmas in dromedary camels from Somalia and the first report of A. lepidum and R. humeralis in Somali dromedary camels.
Current knowledge of tick distribution and tick-borne pathogen presence across Louisiana is limited. Collaborating with veterinarians across the state, ticks removed from companion animals were recovered and assessed for the presence of zoonotic pathogens. A large number of ticks (n = 959) were removed from companion animals and subsequently screened using qPCR for Anaplasma phagocytophilum, Babesia microti, Borrelia burgdorferi, Bartonella henselae, Ehrlichia chaffeensis, and spotted fever group Rickettsia. Five different tick species, Ixodes scapularis (54.5%), Amblyomma americanum (18.4%), Amblyomma maculatum (12.5%), Dermacentor variabilis (11.2%), and Rhipicephalus sanguineus (0.3%) from different regions of Louisiana were collected from October 2018 to July 2019. There were 15 PCR-positive ticks for Rickettsia parkeri (1.6% prevalence), and four ticks were positive for Ehrlichia chaffeensis (0.4% prevalence). This survey identifies ticks and tick-borne pathogens associated with companion animals and areas for future active surveillance.
Several methods of mosquito collection are used for the surveillance of the primary La Crosse virus (LACV) vectors, Aedes triseriatus (Say, 1823), Ae. albopictus (Skuse, 1895), and Ae. japonicus (Theobald, 1901). However, little is known about how the choice of collection method may confound inferences made from LACV vector surveillance data. Therefore, the objective of this study was to investigate potential biases in the surveillance of LACV vectors using the Biogents BG-Sentinel 2 (BGS), CDC-LightTrap (CDC-LT), Biogents Gravid AedesTrap (BG-GAT), and standard oviposition cup (ovicup).The traps were deployed simultaneously at 10 sites in Knovxille,Tennessee, USA for 20 consecutive weeks. Surveillance results differed widely among the traps, demonstrating a strong potential for trap biases in LACV vector surveillance.The BGS and CDC-LT were effective for collecting Ae. albopictus but were not sensitive to the presence of Ae. triseriatus or Ae. japonicus.The ovicup was the best trap for detecting Ae. triseriatus, while the BG-GAT was the only trap that regularly collected Ae. japonicus. Surveillance conducted with the CDC-LT or BGS indicated that Ae. albopictus was dominant at all sites, but the ovicup and BG-GAT suggested a much larger relative abundance of Ae. triseriatus and Ae. japonicus, respectively. Aedes albopictus and Ae. triseriatus collected in the BG-GAT were significantly larger than those collected from the BGS and CDC-LT, indicating that the traps sampled different sub-populations. A multi-method surveillance approach is recommended to reduce potential biases when conducting surveillance of LACV vectors.
Tick-borne diseases constitute the predominant vector-borne health threat in North America. Recent observations have noted a significant expansion in the range of the black-legged tick (Ixodes scapularis Say, Acari: Ixodidae), alongside a rise in the incidence of diseases caused by its transmitted pathogens: Borrelia burgdorferi Johnson (Spirochaetales: Spirochaetaceae), Babesia microti Starcovici (Piroplasmida: Babesiidae), and Anaplasma phagocytophilium Zhu (Rickettsiales: Anaplasmataceae), the causative agents of Lyme disease, babesiosis, and anaplasmosis, respectively. Prior research identified environmental features that influence the ecological dynamics of I. scapularis and B. burgdorferi that can be used to predict the distribution and abundance of these organisms, and thus Lyme disease risk. In contrast, there is a paucity of research into the environmental determinants of B. microti and A. phagocytophilium. Here, we use over a decade of surveillance data to model the impact of environmental features on the infection prevalence of these increasingly common human pathogens in ticks across New York State (NYS). Our findings reveal a consistent northward and westward expansion of B. microti in NYS from 2009 to 2019, while the range of A. phagocytophilum varied at fine spatial scales. We constructed biogeographic models using data from over 650 site-year visits and encompassing more than 250 environmental variables to accurately forecast infection prevalence for each pathogen to a future year that was not included in model training. Several environmental features were identified to have divergent effects on the pathogens, revealing potential ecological differences governing their distribution and abundance. These validated biogeographic models have applicability for disease prevention efforts.
Mosquitoes are a significant public health concern due to their role in transmitting various diseases.This study aimed to investigate mosquitoes' diversity, abundance, and ecological aspects, mainly focusing on Aedes (Diptera: Culicidae) mosquitoes, in central Nepal. The research explored variations across regions, seasons, altitudes, and years. Fieldwork for mosquito collection was conducted between May 2022 and October 2023. Dipping and pipetting methods were employed to collect larvae and pupae, whereas Biogents-Mosquitaire trap captured adult mosquitoes. A total of 7,223 (3,640 larvae and 3,583 adults) mosquitoes, belonging to 8 genera and 18 species, were collected and analyzed. Additionally, a survey examined 5,941 wet containers of 20 different types to assess potential breeding sites.The study revealed Culex pipiens (Linnaeus, 1758) (34.13%) and Aedes albopictus (Skuse, 1895) (27.36%) as the most abundant species. Interestingly, larvae were predominantly Aedes spp. (66.13%), whereas only 13.76% of adults belonged to this genus. Mosquito abundance varied across locations and altitudes, with Siwalik region (331–700 m asl) exhibiting the highest numbers.The monsoon season showed the highest overall abundance (1,492). Used tires were identified as significant breeding sites for Aedes mosquitoes, and infestation rates were higher in shaded containers. Seasonal analysis showed the House Index (HI) reaching its peak (10.92%) and the Breteau Index (BI) reaching 23.08% during the monsoon. Conversely, the Container Index (CI) reached its highest point (37.67%) in the post-monsoon season.The results emphasize the need for comprehensive disease prevention strategies at local and national levels, including public awareness campaigns, to address mosquito-borne illnesses in this famous tourist region.
Jacqueline Mojica, Valentina Arévalo, Jose G. Juarez, Ximena Galarza, Karla Gonzalez, Andrés Carrazco, Harold Suazo, Eva Harris, Josefina Coloma, Patricio Ponce, Angel Balmaseda, Varsovia Cevallos
Aedes mosquitoes, as vectors of medically important arthropod-borne viruses (arboviruses), constitute a major public health threat that requires entomological and epidemiological surveillance to guide vector control programs to prevent and reduce disease transmission. In this study, we present the collaborative effort of 1 year of Aedes ageypti (Linnaeus, 1762) mosquito-based arbovirus surveillance in 2 geographically distinct regions of Latin America (Nicaragua and Ecuador). Adult female mosquitoes were collected using backpack aspirators in over 2,800 randomly selected households (Nicaragua, Ecuador) and 100 key sites (Nicaragua) from 8 distinct communities (Nicaragua: 2, Ecuador: 6). A total of 1,358 mosquito female pools were processed for RNA extraction and viral RNA detection using real-time reverse transcription-polymerase chain reaction. Ten positive dengue virus (DENV) pools were detected (3 in Nicaragua and 7 in Ecuador), all of which were found during the rainy season and matched the serotypes found in humans (Nicaragua: DENV-1 and DENV-4; Ecuador: DENV-2). Infection rates ranged from 1.13 to 23.13, with the Nicaraguan communities having the lowest infection rates. Our results demonstrate the feasibility of detecting DENV-infected Aedes mosquitoes in low-resource settings and underscore the need for targeted mosquito arbovirus sampling and testing, providing valuable insights for future surveillance programs in the Latin American region.
Trypanosoma cruzi (Chagas, 1909) is a protozoan parasite transmitted by triatomine (Hemiptera: Reduviidae) insects and is the causative agent of Chagas disease. Oral transmission of the parasite occurs through consumption of contaminated food or infected triatomines and may depend on the degree to which T. cruzi survives in triatomine abdomens. Dead triatomines may be abundant in areas with insecticide use, such as dog kennels where animals may encounter them. We attempted to culture T. cruzi from the gut material of 108 triatomines collected near dog kennels—14 found alive and 94 found dead—and also tested for T. cruzi DNA and discrete typing units using PCR. In total, 30 (27.8%) tested positive for T. cruzi using PCR, 5 alive (35.7%) and 25 dead (26.6%), with no difference in infection between insects found alive versus dead (P-value = 0.53) and more PCR positives identified in dead triatomines with intact gut contents than in dead desiccated triatomines (P-value = 0.049). One Paratriatoma lecticularia (Stål, 1859) that was found dead (1.1%, n = 94) had T. cruzi growth in culture. Given the use of bleach for external decontamination of triatomines as well as the level of bacterial and fungal contamination of cultures, both of which may have impacted the growth of T. cruzi, the apparent prevalence of viable parasites in this study should be interpreted as a conservative estimate. Vector control initiatives should consider that dead insects may still pose a risk of T. cruzi transmission to animals and humans.
This article is only available to subscribers. It is not available for individual sale.
Access to the requested content is limited to institutions that have
purchased or subscribe to this BioOne eBook Collection. You are receiving
this notice because your organization may not have this eBook access.*
*Shibboleth/Open Athens users-please
sign in
to access your institution's subscriptions.
Additional information about institution subscriptions can be foundhere