Habitat preference and usage by disease vectors are directly correlated with landscapes often undergoing anthropogenic environmental change. A predominant type of land use change occurring in the United States is the expansion of native and non-native woody plant species in grasslands, but little is known regarding the impact of this expansion on regional vector-borne disease transmission. In this study, we focused on the impact of expanding eastern redcedar (Juniperus virginiana; ERC) and tested two hypotheses involving relationships between habitat preferences of adult tick species in rural habitats in central Oklahoma. Using CO₂ traps, we collected ticks from two densities of ERC and grassland and screened adult ticks for the presence of pathogen DNA. We found support for our first hypothesis with significantly more Amblyomma americanum (Linnaeus) and Dermacentor variabilis (Say) collected in ERC habitats than in grassland. Our second hypothesis was also supported, as Ehrlichia- and Rickettsia-infected A. americanum were significantly more likely to be collected from ERC habitats than grassland. As the first evidence that links woody plant encroachment with important tick-borne pathogens in the continental United States, these results have important ramifications involving human and companion animal risk for encountering pathogen-infected ticks in the southern Great Plains.

Variation in vector traits can modulate local scale differences in pathogen transmission. Here, we compared seasonal variation in the wing length (proxy for body size) and energy reserves of adult wild-caught Aedes aegypti populations from a dengue endemic (Kilifi) and non-endemic (Isiolo) area of Kenya. Vector sampling in the dengue endemic site was conducted during the dry and wet seasons. In the non-endemic area, it was limited to the dry season which characterizes this ecology where sporadic or no rainfall is commonplace during the year. We found variation by site in the body size of both sexes, with an overall smaller size of Ae. aegypti populations collected from Isiolo than those from Kilifi. Our results show that although total carbohydrates and lipids levels were highest in both sexes during the dry season, they were two-fold higher in males than females. However, we found weak correlations between body size and energy reserves for both sexes, with body size being more sensitive in identifying differences at a population level. These results provide insights into the determinants of the vectoring potential of Ae. aegypti populations in dengue endemic and non-endemic ecologies in Kenya.

The colonization of the African malaria vector Anopheles funestus has been hampered by inadequate knowledge of its mating and development under laboratory conditions. Life-tables are routinely used to provide baseline biological characteristics needed for colonization. This study characterized age-specific life-table attributes of an existing An. funestus laboratory strain to gain insight into factors that are critical for its colonization. To achieve this, the An. funestus laboratory strain was reared from eggs to adulthood under standard insectary conditions, monitoring and characterizing each developmental stage. The mean insemination rate of females was 74.8% with an average egg load of 67.1 eggs/female and a mean fertility of 86.7%. The mean developmental time from 1^st instar larvae (L1) to pupation was 16.4 days. The mean proportion of L1 that survived to pupation was 72.9%. On average, 78.8% of the pupae successfully eclosed as adults. The median longevity for adult males and females was 44 and 28 days, respectively. This work constitutes the first report on life-table characterization of an An. funestus strain. The larval developmental time was within the range reported for wild An. funestus while adult longevity was higher compared to survivorship observed in wild populations. These data demonstrate that the colonized An. funestus strain has potential to be re-colonized under standard insectary conditions. The study provides base-line information for further studies on identifying critical parameters for the maintenance of An. funestus under artificial conditions.

Attractive toxic sugar baits (ATSB) are a novel and effective mosquito control tool based on sugar-feeding behaviors and oral ingestion. In general, there is a demand from consumers for more novel control products with more effective active ingredients. Bacillus thuringiensis israelensis (BTi) is a major larvicide for control of mosquito larvae. This study evaluated BTi as an active ingredient of toxic sugar baits (TSB) against adult Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus, compared with a positive control of 1% boric acid toxic sugar bait. Ingestion of BTi TSB by female mosquitoes resulted in an average mortality at 48 h of 97% for Ae. aegypti, 98% for Ae. albopictus, and 100% for Cx. quinquefasciatus. The study findings suggest ingestible BTi TSBs could be a viable alternative to current mosquito control strategies and programs against adults of these three species of mosquitoes.

Anthropogenic land-use change may affect the transmission risk for endemic vector-borne diseases such as La Crosse encephalitis. In this study, we applied a comparative ecological approach to evaluate differences in vector species abundance, gonotrophic status, and environmental variables among six residential habitats (historical case houses) and six paired adjacent forest patches in a La Crosse virus endemic area of North Carolina. A total of 93,158 container Aedes spp. eggs were obtained by ovistrips and 1,040 resting mosquito adults were collected by large-bore aspiration from 10 June through 8 October, 2010. At sites characterized by high densities of artificial containers, the totals of eggs and adult mosquitoes were higher in the peridomestic plots. At sites characterized by lower densities of artificial containers, the totals of eggs and adult mosquitoes were higher in the forested plots. Although Aedes triseriatus, the primary La Crosse virus vector, was more commonly found in forested habitat overall, in sites characterized by high density of artificial containers, it was found in higher abundance in the peridomestic habitat. Similarly, the proportion of gonotrophically active (parous and gravid) mosquitoes was higher in the peridomestic habitat for sites with highartificial container density. Our study suggests that La Crosse virus transmission risk may be higher at peridomestic habitats with higher densities of artificial containers and thus reinforces the importance of public health measures to improve source reduction efforts.

During the course of a plague epizootic, decimation of rodent host populations may result in the transfer of fleas to alternate or phoretic hosts, including to sympatric raptors that prey on rodents. We studied flea abundance and flea species assemblages on burrowing owls (Athene cunicularia hypugaea) in southwestern Idaho before (2012 – 2014), during (2015 – 2016), and after (2017) an epizootic of plague in Piute ground squirrels (Urocitellis mollis). We examined (1) if a larger proportion of burrowing owl nests contained fleas, (2) the likelihood that owls within a high flea abundance class increased, and (3) if owls harbored ground squirrel fleas during the epizootic. Using a flea abundance index assigned to 1,184 owls from 236 nests, the proportion of nests and the likelihood that owls had high flea abundance decreased rather than increased during epizootic years. Moreover, of 3,538 collected fleas from owls at 143 nests, no fleas were species that Piute ground squirrels typically harbor. Instead, Pulex irritans was the predominant flea collected in all study years (> 99%). Thus, although raptors may play a role in plague, there was no evidence that the die-off of ground squirrels resulted in higher flea intensity in burrowing owls or that they served as frequent accidental or phoretic hosts for ground squirrel fleas that could potentially be infectious with Yersinia pestis.

Several important biological parameters for estimating the vectorial capacity of a triatomine species were determined on a Mexican population of the recently described Triatoma huehuetenanguensis Lima-Cordón, Monroy, Stevens, Rodas, Rodas, Dorn, Justi (Hemiptera: Reduviidae: Triatominae). The biological parameters were the egg-to-adult development time, number of blood meals required for molting, cumulative mortality, onset time for feeding, feeding and defecation behaviors, and fertility and fecundity of T. huehuetenanguensis. The median egg-to-adult development time was 253 days, with 11 blood meals required for molting. A cumulative mortality rate of 47.41% was observed. The time to begin feeding was between 2.5 and 3.5 min. Feeding times were longer than 15 min. The highest percentages of defecation delays were 1 to 10 min in all nymphal instars and also in males. In contrast, significantly (P < 0.01) more females defecated while eating. At the end of the cycle, the percentage of the obtained females was 54.9%. The mean number of eggs laid per day per female for a month was 2.08. These eggs had an eclosion rate of 98.08%, with an incubation period of 19 days. Our results contribute to estimations of the potential role of T. huehuetenanguensis in the transmission of Trypanosoma cruzi in its distribution area.

Global climate change and the accompanying rise in temperature could affect the biology and ecology of a number of vectors, including mosquitoes. High altitude areas that were previously unsuitable for the spread of mosquito vector populations could become suitable. The aim of this research was to study the distribution of mosquito species in higher altitude regions of Croatia. Samples were collected in three areas: Slavonian Mountains, Gorski Kotar, and Middle Velebit. Specimens were morphologically determined and confirmed by DNA barcoding and other genetic markers and showed the presence of 16 species belonging to six genera. The most abundant species were the Culex pipiens complex with 50% of the collected specimens. Both pipiens (Linnaeus, 1758) and molestus (Forskal, 1775) biotypes and their hybrids were identified within the complex, followed by Culex torrentium (Martini, 1925) (20.2%), Culiseta longiareolata (Macquart, 1838) (8.5%), and the invasive species Aedes japonicus (Theobald, 1901) (7.8% of the total number of collected specimens). The remaining 12 species made up 14.7% of the collected specimens. Intraspecific COI p-distances were within the standard barcoding threshold for OTUs, while interspecific genetic distances were much higher, confirming the existence of barcoding gaps. Mosquito fauna of Croatian mountains showed a moderate variety and made 30.8% of the total number of recorded mosquito species in Croatia thus far.

An important element of vector control and surveillance of mosquito-borne diseases is updated information on vector species distribution. The aim of this study was to collect available information about mosquito species reported in Extremadura between 1920 and 2020 and create a catalog that would combine both published data and our recent field identifications. An exhaustive list is hereby presented, including species status and detailed distribution maps at a municipal level as well as their importance for public health. A total of 33 species, classified into five genera: Anopheles (five species), Aedes (14), Culex (nine), Culiseta (four), and Orthopodomyia (one) has been recorded, including 31 autochthonous, one invasive, Aedes (Stegomyia) albopictus, and one disappeared since 1953, Aedes (Stegomyia) aegypti. For the first time in Extremadura, we report the presence of important vectors such as Aedes (Aedimorphus) vexans vexans and Culex (Culex) perexiguus, and the new record of six species in the province of Badajoz, namely: Aedes (Dahliana) echinus, Aedes (Fredwardsius) vittatus, Aedes (Ochlerotatus) berlandi, Aedes (Ochlerotatus) pulcritarsis, Culex (Culex) mimeticus, and Culiseta (Culiseta) subochrea. Nineteen of these species are potential vectors of medical and veterinary relevance.

American trypanosomiasis is a zoonosis caused by the parasite Trypanosoma cruzi and is transmitted mainly by blood-sucking insects belonging to the subfamily Triatominae. The importance of this parasite lies in its wide geographical distribution, high morbidity, and the fact that there has not yet been an effective treatment or vaccine. Previous studies have detailed the interactions between different triatomine species and T. cruzi strains. However, the factors necessary to establish infection in triatomines have not yet been fully elucidated. Furthermore, it is postulated that the coexistence between the parasite and triatomines could modulate the susceptibility to infection in these insects. Accordingly, in this study, we evaluated the susceptibility to T. cruzi infection in the species Triatoma (Meccus) pallidipennis, Triatoma barberi, and Triatoma lecticularia, which were infected with Ninoa, H8, INC-5, Sontecomapan, and Hueypoxtla strains. The criteria used to establish susceptibility were the amount of blood ingested by the insects, percentage of infected triatomines, concentration of parasites in feces, and percentage of metacyclic trypomastigotes in feces. These parameters were analyzed by fresh examination and differential count with Giemsa-stained smears. Our main findings suggest the following order of susceptibility concerning infection with T. cruzi: T. lecticularia > T. barberi > T. (Meccus) pallidipennis. Furthermore, the study concludes that an increased susceptibility to infection of triatomines that share the same geographic region with different strains of T. cruzi is not always a fact.

We present the first records of Coquillettidia (Coquillettidia) buxtoni (Edwards, 1923) (n=15), Culex (Neoculex) impudicus Ficalbi, 1890 (n=12), Culex (Neoculex) territans Walker, 1856 (n=52), Culiseta (Culicella) fumipennis (Stephens, 1825) (n=535), and Culiseta (Culicella) morsitans (Theobald, 1901) (n=54) in the Autonomous Community of Galicia (NW Spain), including the first evidence of the genus Coquillettidia Dyar, 1904 in the northwest of Spain. The field research was carried out in different water ecosystems (ponds, streams, rivers, lakes, and lagoons) belonging to 39 zones throughout the entire Galician territory. The samples were collected intermittently and seasonally through different projects of water quality monitoring between 1998 and 2018. A total of 1,614 mosquito larvae have been analyzed, and 668 of them were identified as species not previously recorded in Galicia. Between 1999 and 2003, the first catches of these species were obtained and since then, more specimens have been detected in different wetlands of Galicia, mainly in spring and summer.

Aedes albopictus (Skuse, 1894) has a widespread distribution that includes both temperate and tropical climates. It is a potential vector of several important worldwide arboviruses, including chikungunya, zika, and dengue, and its geographical distribution expands rapidly. Despite its vectorial importance, the bioecological features of this species in newly established environments are still not very well known. Thus, this study investigated phenotypic variations among Ae. albopictus populations from different regions in Turkey. This is the first comparative morphological study of Ae. albopictus populations in Turkey. The procrustes distances phenogram derived from wing data indicates that the shape differences among some populations and the population from the Aegean coast differ from the Black Sea populations. Size differences were also detected between some populations.