12 research outputs found
Evaluation of the vector competence of a native UK mosquito Ochlerotatus detritus (Aedes detritus) for dengue, chikungunya and West Nile viruses
BACKGROUND: To date there has been no evidence of mosquito-borne virus transmission of public health concern in the UK, despite the occurrence of more than 30 species of mosquito, including putative vectors of arboviruses. The saltmarsh mosquito Ochlerotatus detritus [syn. Aedes (Ochlerotatus) detritus] is locally common in parts of the UK where it can be a voracious feeder on people. METHODS: Here, we assess the competence of O. detritus for three major arboviruses: dengue virus (DENV), chikungunya virus (CHIKV) and West Nile virus (WNV) using adult mosquitoes reared from wild, field-obtained immatures. RESULTS: We demonstrate laboratory competence for WNV at 21 °C, with viral RNA detected in the mosquito’s saliva 17 days after oral inoculation. By contrast, there was no evidence of laboratory competence of O. detritus for either DENV or CHIKV. CONCLUSIONS: To our knowledge, this is the first study to demonstrate competence of a UK mosquito for WNV and confirms that O. detritus may present a potential risk for arbovirus transmission in the UK and that further investigation of its vector role in the wild is required
Laboratory transmission potential of British mosquitoes for equine arboviruses
Background: There has been no evidence of transmission of mosquito-borne arboviruses of equine or human health
concern to date in the UK. However, in recent years there have been a number of outbreaks of viral diseases spread by
vectors in Europe. These events, in conjunction with increasing rates of globalisation and climate change, have led to
concern over the future risk of mosquito-borne viral disease outbreaks in northern Europe and have highlighted the
importance of being prepared for potential disease outbreaks. Here we assess several UK mosquito species for their
potential to transmit arboviruses important for both equine and human health, as measured by the presence of viral
RNA in saliva at diferent time points after taking an infective blood meal.
Results: The following wild-caught British mosquitoes were evaluated for their potential as vectors of zoonotic
equine arboviruses: Ochlerotatus detritus for Venezuelan equine encephalitis virus (VEEV) and Ross River virus (RRV),
and Culiseta annulata and Culex pipiens for Japanese encephalitis virus (JEV). Production of RNA in saliva was demonstrated at varying efciencies for all mosquito-virus pairs. Ochlerotatus detritus was more permissive for production
of RRV RNA in saliva than VEEV RNA. For RRV, 27.3% of mosquitoes expectorated viral RNA at 7 days post-infection
when incubated at 21 °C and 50% at 24 °C. Strikingly, 72% of Cx. pipiens produced JEV RNA in saliva after 21 days at 18
°C. For some mosquito-virus pairs, infection and salivary RNA titres reduced over time, suggesting unstable infection
dynamics.
Conclusions: This study adds to the number of Palaearctic mosquito species that demonstrate expectoration of viral
RNA, for arboviruses of importance to human and equine health. This work adds to evidence that native mosquito
species should be investigated further for their potential to vector zoonotic mosquito-borne arboviral disease of
equines in northern Europe. The evidence that Cx. pipiens is potentially an efcient laboratory vector of JEV at temperatures as low as 18 °C warrants further investigation, as this mosquito is abundant in cooler regions of Europe and
is considered an important vector for West Nile Virus, which has a comparable transmission ecolog
Female preferences drive the evolution of mimetic accuracy in male sexual displays
Males in many bird species mimic the vocalizations of other species during sexual displays, but the evolutionary and functional significance of interspecific vocal mimicry is unclear. Here we use spectrographic cross-correlation to compare mimetic calls produced by male satin bowerbirds (Ptilonorhynchus violaceus) in courtship with calls from several model species. We show that the accuracy of vocal mimicry and the number of model species mimicked are both independently related to male mating success. Multivariate analyses revealed that these mimetic traits were better predictors of male mating success than other male display traits previously shown to be important for male mating success. We suggest that preference-driven mimetic accuracy may be a widespread occurrence, and that mimetic accuracy may provide females with important information about male quality. Our findings support an alternative hypothesis to help explain a common element of male sexual displays