Mosquitoes are important vectors of disease pathogens and multiple species are undergoing geographical shifts due to global changes. As such, there is a growing need for accurate distribution predictions. Ecological niche modelling (ENM) is an effective tool to assess mosquito distribution patterns and link these to underlying environmental preferences. Typically, macroclimatic variables are used as primary predictors of mosquito distributions. However, they likely undervalue local conditions and intraspecific variation in environmental preferences. This is problematic, as mosquito control takes place at the local scale. Utilising high-resolution (10 × 10 m) Maxent ENMs on the island of Bonaire as model system, we explore the influence of local environmental variables on mosquito distributions. Our results show a distinct set of environmental variables shape distribution patterns across ecologically-distinct species, with urban variables strongly associated with introduced species like Aedes aegypti and Culex quinquefasciatus, while native species show habitat preferences for either mangroves, forests, or ephemeral water habitats. These findings underscore the importance of distinct local environmental factors in shaping distributions of different mosquitoes, even on a small island. As such, these findings warrant further studies aimed at predicting high-resolution mosquito distributions, opening avenues for preventative management of vector-borne disease risks amidst ongoing global change and ecosystem degradation.
- MeSH
- Aedes fyziologie MeSH
- Culex fyziologie MeSH
- Culicidae * fyziologie MeSH
- ekosystém * MeSH
- komáří přenašeči * fyziologie MeSH
- rozšíření zvířat MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Musca domestica L., a common housefly, and Culex quinquefasciatus mosquito are quite well-known pests that can transfer a wide range of diseases to humans as well as animals. In this study, various isoborneol derivatives including esters, ethers, and thioethers were synthesized from isoborneol under mild conditions. These derivatives were evaluated for inhibition of house-fly M. domestica adults and Cx. quinquefasciatus larvae. Two of the synthesized isoborneol ester derivatives (2 and 3) showed good activity against both insect species. Additional two derivatives (6 and 9) were active against M. domestica L., and the derivatives (1-3, 8) were active against Cx. quinquefasciatus larvae.
- Klíčová slova
- Culex quinquefasciatus, Musca domestica, Ethers, Isoborneol esters, Thioethers,
- MeSH
- Culex * účinky léků MeSH
- insekticidy * farmakologie chemie MeSH
- larva * účinky léků MeSH
- moucha domácí * účinky léků MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- insekticidy * MeSH
Body mass underpins many ecological processes at the level of individuals, populations, and communities. Often estimated in arthropods from linear morphological traits such as body length or head width, these relationships can vary even between closely related taxa. Length-mass relationships of mosquito (Diptera: Culicidae) larvae are poorly known despite the importance of this family to disease and aquatic ecology. To fill this gap, we measured ontogenetic changes in linear traits (body length, head width, and thorax width) and dry and wet masses and estimated length- and width-mass relationships in larvae of 3 culicid species inhabiting different niches: the tropical Aedes albopictus (Skuse, 1894), the temperate Culex pipiens (Linnaeus, 1758), and the snowmelt Ochlerotatus punctor (Kirby, 1837). We compared our results with published length-mass allometries of other aquatic dipteran larvae. We showed that thorax width and body length, but not head width, reliably predicted body mass for our 3 species. The length-mass allometry slopes in aquatic dipterans varied considerably between and within families but were independent of phylogeny, specimen handling, preservation techniques, and data fitting methods. Slope estimates became less precise with decreasing sample size and size range. To obtain reliable estimates of the allometric slopes, we have thus recommended using data on all larval stages for intraspecific allometries and a wide range of species for interspecific allometries. We also cautioned against the indiscriminate use of length-mass allometries obtained for other taxa or collected at lower taxonomic resolutions, e.g., when using length-mass relationships to estimate biomass production at a given site.
Compounds isolated from botanical sources represent innovative and promising alternatives to conventional insecticides. Carlina oxide is a compound isolated from Carlina acaulis L. (Asteraceae) essential oil (EO) with great potential as bioinsecticide, being effective on various arthropod vectors and agricultural pests, with moderate toxicity on non-target species. Since the production from the wild source is limited, there is the need of exploring new synthetic routes for obtaining this compound and analogues with improved bioactivity and lower toxicity. Herein, the chemical synthesis of carlina oxide analogues was developed. Their insecticidal activity was assessed on the vectors Musca domestica L. and Culex quinquefasciatus Say, and their cytotoxicity was evaluated on a human keratinocyte cell line (HaCaT). The compounds' activity was compared with that of the natural counterparts EO and carlina oxide. In housefly tests, the analogues were comparably effective to purified carlina oxide. In Cx. quinquefasciatus assays, the meta-chloro analogue provided a significantly higher efficacy (LC50 of 0.71 μg mL-1) than the EO and carlina oxide (LC50 1.21 and 1.31 μg mL-1, respectively) and a better safety profile than carlina oxide on keratinocytes. Overall, this study can open the way to an agrochemical production of carlina oxide analogues employable as nature-inspired insecticides.
- MeSH
- Asteraceae * chemie MeSH
- Culex * MeSH
- insekticidy * farmakologie MeSH
- komáří přenašeči MeSH
- larva MeSH
- lidé MeSH
- oleje prchavé * farmakologie chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- carlina oxide MeSH Prohlížeč
- insekticidy * MeSH
- oleje prchavé * MeSH
BackgroundDespite the known circulation of West Nile virus (WNV) and Usutu virus (USUV) in Slovakia, no formal entomological surveillance programme has been established there thus far.AimTo conduct contemporaneous surveillance of WNV and USUV in different areas of Slovakia and to assess the geographical spread of these viruses through mosquito vectors. The first autochthonous human WNV infection in the country is also described.MethodsMosquitoes were trapped in four Slovak territorial units in 2018 and 2019. Species were characterised morphologically and mosquito pools screened for WNV and USUV by real-time reverse-transcription PCRs. In pools with any of the two viruses detected, presence of pipiens complex group mosquitoes was verified using molecular approaches.ResultsAltogether, 421 pools containing in total 4,508 mosquitoes were screened. Three pools tested positive for WNV and 16 for USUV. USUV was more prevalent than WNV, with a broader spectrum of vectors and was detected over a longer period (June-October vs August for WNV). The main vectors of both viruses were Culex pipiens sensu lato. Importantly, WNV and USUV were identified in a highly urbanised area of Bratislava city, Slovakias' capital city. Moreover, in early September 2019, a patient, who had been bitten by mosquitoes in south-western Slovakia and who had not travelled abroad, was laboratory-confirmed with WNV infection.ConclusionThe entomological survey results and case report increase current understanding of the WNV and USUV situation in Slovakia. They underline the importance of vector surveillance to assess public health risks posed by these viruses.
- Klíčová slova
- Europe, Slovakia, Usutu, West Nile, arbovirus, flavivirus, mosquitoes,
- MeSH
- Culex * MeSH
- Culicidae * MeSH
- Flavivirus * genetika MeSH
- lidé MeSH
- virus západního Nilu * genetika MeSH
- západonilská horečka * diagnóza epidemiologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- Geografické názvy
- Slovenská republika epidemiologie MeSH
The risks of depletion of energy reserves and encountering lethally low temperatures are considered as two important mortality factors that may limit winter survival of mosquito, Culex pipiens f. pipiens populations. Here we show that the autumn females carry lipid reserves, which are safely sufficient for at least two overwintering periods, provided the females diapausing at temperatures typical for underground spaces (0 °C - 8 °C) would continuously rest at a standard metabolic rate (SMR). The overwintering females, however, switch from SMR to much higher metabolic rate during flight, either seeking for optimal microhabitat within the shelter or in response to disturbances by air current or predator attack. These behaviors result in fast oxidation of lipid reserves and, therefore, the autumn load of energy reserves may actually limit winter survival under specific circumstances. Next, we show that the level of females' cold hardiness is physiologically set relatively weak for overwintering in open field, above-ground habitats, but is ecologically entirely sufficient for overwintering in most underground spaces. The characteristics of suitable overwintering shelters are: no or limited risk of contact with ice crystals, no or limited air movements, winter temperatures relatively stable between +2 and + 6 °C, winter minimum does not drop below -4 °C for longer than one week, or below -8 °C for longer than 1 day.
- Klíčová slova
- Cold tolerance, Culex pipiens, Energy reserves, Insects, Overwintering,
- MeSH
- Culex metabolismus fyziologie MeSH
- diapauza MeSH
- energetický metabolismus * MeSH
- metabolismus lipidů MeSH
- nízká teplota * MeSH
- roční období * MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Coumarin (2H-1-benzopyran-2-one) is a phenolic compound derived from the shikimate pathway and synthesized by various medicinal and aromatic plants as parent molecule of a large group of secondary metabolites, namely coumarins. Its main utilization is as fixative in perfumes and flavour enhancer. Given its role as phytoalexin and phagodepression activity, herein we evaluated for the first time its efficacy against several insect species: the green peach aphid, Myzus persicae, the moth Spodoptera littoralis, the housefly, Musca domestica and the filariasis vector Culex quinquefasciatus. Two non-target species were also included in our toxicity evaluation experiments: the ladybug Harmonia axyridis and the earthworm Eisenia fetida. Results highlighted remarkable selectivity of coumarin, being highly toxic to M. persicae aphids (LC50(90) values of 1.3(1.9) mg L-1) and friendly to natural enemies of aphids as well as soil invertebrates.
- Klíčová slova
- Aphid, earthworm, insecticide, ladybug, mosquito, moth, non-target species,
- MeSH
- Culex účinky léků MeSH
- inhibiční koncentrace 50 MeSH
- insekticidy toxicita MeSH
- kumariny toxicita MeSH
- larva účinky léků MeSH
- moucha domácí účinky léků MeSH
- mšice účinky léků MeSH
- můry účinky léků MeSH
- rostlinné extrakty chemie MeSH
- semena rostlinná chemie MeSH
- Spodoptera účinky léků MeSH
- testy toxicity MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- coumarin MeSH Prohlížeč
- insekticidy MeSH
- kumariny MeSH
- rostlinné extrakty MeSH
Host blood protein digestion plays a pivotal role in the ontogeny and reproduction of hematophagous vectors. The gut of hematophagous arthropods stores and slowly digests host blood and represents the primary gateway for transmitted pathogens. The initial step in blood degradation is induced lysis of host red blood cells (hemolysis), which releases hemoglobin for subsequent processing by digestive proteolytic enzymes. The activity cycles and characteristics of hemolysis in vectors are poorly understood. Hence, we investigated hemolysis in two evolutionarily distant blood-feeding arthropods: The mosquito Culex pipiens and the soft tick Argas persicus, both of which are important human and veterinary disease vectors. Hemolysis in both species was cyclical after blood meal ingestion. Maximum digestion occurs under slightly alkaline conditions in females. Hemolytic activity appears to be of lipoid origin in C. pipiens and enzymatic activity (proteolytic) in A. persicus. We have assessed the effect of pH, incubation time, and temperature on hemolytic activity and the hemolysin. The susceptibility of red blood cells from different hosts to the hemolysin and the effect of metabolic inhibition of hemolytic activity were assessed. We conclude that in C. pipiens and A. persicus midgut hemolysins control the amplitude of blood lysis step to guarantee an efficient blood digestion.
- MeSH
- členovci - vektory fyziologie MeSH
- členovci MeSH
- Culex MeSH
- Culicidae MeSH
- erytrocyty MeSH
- hematologické testy MeSH
- hemolýza * MeSH
- hemolyziny MeSH
- komáří přenašeči fyziologie MeSH
- lidé MeSH
- stravovací zvyklosti fyziologie MeSH
- trávicí systém MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- hemolyziny MeSH
The overwintering strategy of the mosquito Culex modestus, an important West Nile virus (WNV) vector in Europe, was explored under field conditions in reedbed (Phragmites australis) ecosystems in early 2019. A total of 30 Cx. modestus females were found in a BG-Sentinel trap placed in a plastic greenhouse as well as in a reference BG-Sentinel trap placed under the open sky, both set up within the reedbeds and inspected every 2-3 days from February 27 to April 10, 2019. Moreover, 186 females of Cx. pipiens, 3 females of Anopheles hyrcanus, and 3 females of Culiseta annulata were trapped in the monitored time span. While all Cx. modestus females tested negative for the presence of WNV and other arboviruses circulating in Central Europe, we confirmed WNV lineage 2 and Ťahyna virus infection in several pools of the collected Cx. pipiens, demonstrating arbovirus overwintering. This pilot study highlights the need for large-scale monitoring activities covering different regions to identify the overwintering strategy of both mosquito-borne viruses and their vectors in Central Europe.
- Klíčová slova
- Anopheles hyrcanus, Culex modestus, Culex pipiens, Culiseta annulata, arboviruses, overwintering,
- MeSH
- Culex fyziologie virologie MeSH
- ekosystém * MeSH
- roční období MeSH
- virus západního Nilu izolace a purifikace MeSH
- viry kalifornské encefalitidy izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Medicinal and aromatic plants represent an outstanding source of green active ingredients for a broad range of real-world applications. In the present study, we investigated the insecticidal potential of the essential oils obtained from three medicinal and aromatic plants of economic importance in Algeria, Artemisia campestris, Pulicaria arabica, and Saccocalyx satureioides. Gas chromatography coupled with mass spectrometry (GC-MS) was used to study the essential oil chemical compositions. The three essential oils were tested against a mosquito vectoring filariasis and arboviruses, i.e., Culex quinquefasciatus, a fly pest acting also as pathogens vector, Musca domestica, and an agricultural moth pest, i.e., Spodoptera littoralis, using WHO and topical application methods, respectively. The essential oil from A. campestris, containing β-pinene (15.2%), α-pinene (11.2%), myrcene (10.3%), germacrene D (9.0%) (Z)-β-ocimene (8.1%) and γ-curcumene (6.4%), showed remarkable toxicity against C. quinquefasciatus (LC50 of 45.8 mg L-1) and moderate effects (LD50 of 99.8 μg adult-1) against M. domestica. Those from P. arabica and S. satureioides, containing epi-α-cadinol (23.9%), δ-cadinene (21.1%), α-cadinol (19.8%) and germacrene D-4-ol (8.4%), and thymol (25.6%), α-terpineol (24.6%), borneol (17.4%) and p-cymene (11.4%), respectively, were more active on S. littoralis showing LD50 values of 68.9 and 61.2 μg larva-1, respectively. Based on our results, the essential oil from A. campestris may be further considered a candidate ingredient for developing botanical larvicides.
- Klíčová slova
- Culex quinquefasciatus, Green pesticide, Insect pest, Mosquito vector, Musca domestica, Spodoptera littoralis,
- MeSH
- Culex * MeSH
- insekticidy * MeSH
- larva MeSH
- léčivé rostliny * MeSH
- oleje prchavé * MeSH
- pelyněk * MeSH
- Pulicaria * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Alžírsko MeSH
- Názvy látek
- insekticidy * MeSH
- oleje prchavé * MeSH
