scholarly journals Gonoactivity of Culex (Culex) (Diptera: Culicidae) Mosquitoes During Winter in Temperate Argentina

Author(s):  
María Florencia Branda ◽  
Magdalena Laurito ◽  
Andrés Mario Visintin ◽  
Walter Ricardo Almirón

Abstract The subgenus Culex L. includes species involved in summer–autumn arbovirus transmission but studies during winter are scarce in temperate Argentina. Female specimens were collected host-seeking at dry-ice-baited traps during autumn–winter–spring at two sites in Córdoba City during 2016 and 2017. The specimens were morphologically identified and dissected to determine the follicular developmental stage (gonotrophic activity). Females with advanced follicular stages (≥III) were subjected to molecular procedures to confirm or re-identify previous morphological identification. Five species (Culex apicinus Philippi (Diptera: Culicidae), Culex dolosus (Lynch-Arribálzaga) (Diptera: Culicidae), Culex maxi Dyar (Diptera: Culicidae), Culex pipiens pipiens L. (Diptera: Culicidae), and Culex quinquefasciatus Say (Diptera: Culicidae)) were collected and found gonoactive during winter; showing that a high proportion of Culex (Culex) females remain reproductively active during the unfavorable season for mosquito populations. Among them, it is worth noting the collection of Cx. quinquefasciatus, vector of the St. Louis encephalitis virus (endemic in the city), a specimen of Cx. p. pipiens, and a hybrid of Cx. p. pipiens/Cx. quinquefasciatus (during autumn). The study of this community during winter should continue because a high gonoactive female proportion with advanced follicular stages was found: 29.12 and 13.07% in 2016 and 2017, respectively. Local studies such as this one provide evidence about ornithophilic Culex species with active year-round life cycles, species that could favor arbovirus overwintering.

1986 ◽  
Vol 76 (3) ◽  
pp. 375-383 ◽  
Author(s):  
Thomas G. T. Jaenson ◽  
Bo Niklasson

AbstractIn the province of Hälsingland in central Sweden, mosquitoes were sampled in 1983 with rabbit-, guineapig-, hen- and dove-baited and unbaited suction traps and similarly baited net traps. Blood-meals were identified by the precipitin test. Aedes cantans (Meigen), Ae. cinereus Meigen, Ae. communis (De Geer), Ae. diantaeus Howard, Dyar & Knab, Ae. excrucians (Walker) s.l. and Ae. intrudens Dyar were mainly attracted to the mammals, and Culex pipiens pipiens L., Culiseta morsitans (Theobald) and Cs. ochroptera (Peus) mainly to the birds. Significantly larger numbers of Cx. p. pipiens and Cs. morsitans were caught in dove- than in hen-baited traps. Of all identified feeds of engorged Aedes females, 95% were from mammals and 5% from birds. Only feeds from birds were found in engorged Cs. morsitans females. Movement of engorged females between the traps was demonstrated. Some Aedes females entered baited traps shortly after having fed on cervids and/or cattle. In the study area, suspected vectors between birds of Sindbis virus, the causative agent of Ockelbo disease, are Cx. p. pipiens, Cx. torrentium Martini and Cs. ochroptera in late spring and summer and Cs. morsitans in late summer. The isolation of this virus from Cx. p. pipiens and Cs. morsitans females captured in this area supports their role as suspected primary vectors. Ae. communis and other abundant Aedes species are suspected vectors of this virus from birds to man. Ae. cinereus may be a vector of tularaemia (caused by Francisella tularensis) in this area.


2017 ◽  
Vol 96 (5) ◽  
pp. 1235-1240 ◽  
Author(s):  
Joan L. Kenney ◽  
Hannah Romo ◽  
Nisha K. Duggal ◽  
Wen-Pin Tzeng ◽  
Kristen L. Burkhalter ◽  
...  

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 129
Author(s):  
Matthew W. Hopken ◽  
Limarie J. Reyes-Torres ◽  
Nicole Scavo ◽  
Antoinette J. Piaggio ◽  
Zaid Abdo ◽  
...  

Urban ecosystems are a patchwork of habitats that host a broad diversity of animal species. Insects comprise a large portion of urban biodiversity which includes many pest species, including those that transmit pathogens. Mosquitoes (Diptera: Culicidae) inhabit urban environments and rely on sympatric vertebrate species to complete their life cycles, and in this process transmit pathogens to animals and humans. Given that mosquitoes feed upon vertebrates, they can also act as efficient samplers that facilitate detection of vertebrate species that utilize urban ecosystems. In this study, we analyzed DNA extracted from mosquito blood meals collected temporally in multiple neighborhoods of the San Juan Metropolitan Area, Puerto Rico to evaluate the presence of vertebrate fauna. DNA was collected from 604 individual mosquitoes that represented two common urban species, Culex quinquefasciatus (n = 586) and Aedes aegypti (n = 18). Culex quinquefasciatus fed on 17 avian taxa (81.2% of blood meals), seven mammalian taxa (17.9%), and one reptilian taxon (0.85%). Domestic chickens dominated these blood meals both temporally and spatially, and no statistically significant shift from birds to mammals was detected. Aedes aegypti blood meals were from a less diverse group, with two avian taxa (11.1%) and three mammalian taxa (88.9%) identified. The blood meals we identified provided a snapshot of the vertebrate community in the San Juan Metropolitan Area and have potential implications for vector-borne pathogen transmission.


2021 ◽  
Vol 6 (2) ◽  
pp. 45
Author(s):  
Ana Klobucar ◽  
Vladimir Savic ◽  
Marcela Curman Posavec ◽  
Suncica Petrinic ◽  
Urska Kuhar ◽  
...  

In the period from 2015 to 2020, an entomological survey for the presence of West Nile virus (WNV) and Usutu virus (USUV) in mosquitoes was performed in northwestern Croatia. A total of 20,363 mosquitoes were sampled in the City of Zagreb and Međimurje county, grouped in 899 pools and tested by real-time RT-PCR for WNV and USUV RNA. All pools were negative for WNV while one pool each from 2016 (Aedes albopictus), 2017 (Culex pipiens complex), 2018 (Cx. pipiens complex), and 2019 (Cx. pipiens complex), respectively, was positive for USUV. The 2018 and 2019 positive pools shared 99.31% nucleotide homology within the USUV NS5 gene and both clustered within USUV Europe 2 lineage. The next-generation sequencing of one mosquito pool (Cx. pipiens complex) collected in 2018 in Zagreb confirmed the presence of USUV and revealed several dsDNA and ssRNA viruses of insect, bacterial and mammalian origin.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdou Talipouo ◽  
Konstantinos Mavridis ◽  
Elysée Nchoutpouen ◽  
Borel Djiappi-Tchamen ◽  
Emmanouil Alexandros Fotakis ◽  
...  

AbstractCulex mosquitoes particularly Culex quinquefasciatus are important arboviral and filariasis vectors, however despite this important epidemiological role, there is still a paucity of data on their bionomics. The present study was undertaken to assess the insecticide resistance status of Cx. quinquefasciatus populations from four districts of Yaoundé (Cameroon). All Culex quinquefasciatus populations except one displayed high resistance to bendiocarb and malathion with mortalities ranging from 0 to 89% while high resistance intensity against both permethrin and deltamethrin was recorded. Molecular analyses revealed high frequencies of the ACE-1 G119S mutation (ranging from 0 to 33%) and kdr L1014F allele (ranging from 55 to 74%) in all Cx. quinquefasciatus populations. Significant overexpression was detected for cytochrome P450s genes CYP6AA7 and CYP6Z10, as well as for Esterase A and Esterase B genes. The total cuticular hydrocarbon content, a proxy of cuticular resistance, was significantly increased (compared to the S-lab strain) in one population. The study confirms strong insecticide resistance mediated by different mechanisms in Cx. quinquefasciatus populations from the city of Yaoundé. The expansion of insecticide resistance in Culex populations could affect the effectiveness of current vector control measures and stress the need for the implementation of integrated vector control strategies in urban settings.


1968 ◽  
Vol 61 (3) ◽  
pp. 863-864 ◽  
Author(s):  
Ronald Everett ◽  
J. L. Lancaster
Keyword(s):  
Dry Ice ◽  

1985 ◽  
Vol 45 (2) ◽  
pp. 225-230 ◽  
Author(s):  
Dominic S.T. Awahmukalah ◽  
Marion A. Brooks

2021 ◽  
Vol 134 ◽  
pp. 104295 ◽  
Author(s):  
Elise M. Didion ◽  
Zakee L. Sabree ◽  
Laura Kenyon ◽  
Gabriela Nine ◽  
Richard W. Hagan ◽  
...  

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