Association of avian #biodiversity and #WNV circulation in #Culex mosquitoes in Emilia-Romagna, #Italy

Detection of #WNV, #USUV and #Insect-Specific #Bunyaviruses in #Culex spp. Mosquitoes, #Greece, 2024

Discovery and description of a novel mode of oviposition in the mosquito genus Culex - Scientific Reports

Despite the wide variation in mosquito reproductive strategies and the present lack of behavioral and ecological information for the majority of described mosquito species, the predominant egg-laying behaviors observed in well-studied species have led to sweeping generalizations of oviposition patterns across entire mosquito genera. Mosquitoes in the genus Culex, which contains over 800 species across 28 subgenera, are commonly believed to exclusively lay egg masses (“rafts”) that float on the water surface. This oversimplification persists, though we currently know little regarding the reproduction of many Culex species and subgenera. Using field observations, photography, and video recordings, we document the oviposition behavior of a Culex subgenus Micraedes species, Culex antillummagnorum (Dyar), and provide the first evidence, to our knowledge, of a Culex species aerially and skip-ovipositing, rather than laying masses of coniform eggs. Gravid Cx. antillummagnorum females were observed and filmed in the Luquillo Experimental Forest of Puerto Rico for several nights as they performed an elliptic flight pattern while launching single eggs into water-filled bracts of Heliconia caribaea. These findings raise questions regarding the evolution and drivers of such an atypical Culex behavior and indicate that our understanding of Culex ecology and behavior remains incomplete.

Household expenditure on control of urban mosquitoes Aedes albopictus and Culex pipiens in Emilia-Romagna, Northern Italy

Author summary To achieve effectiveness, mosquito control requires the adoption of integrated pest management (IPM) methods and comprehensive strategies in both public and private areas. In the case of urban mosquitoes, the application of IPM in public areas alone may not reduce the insect population density to levels that limit the nuisance, particularly during daytime, and mitigate the risks of arbovirus outbreaks. In Italy, the control activities by local administrations are usually limited to public areas, while interventions in private areas are delegated to owners and residents. This study analyzed the expenses incurred by households to protect themselves from mosquitoes. We found that the average yearly cost per household was about € 84.63 (excluding the depreciation costs of mosquito nets, the average expenditure drops to € 58.63 per household), which was significantly higher than the average expenditure incurred by local administrations for their interventions in public areas (approximately € 3/household/year). The efficacy of domestic mosquito control methods is difficult to estimate due to the variety of strategies, tools and operating conditions. Moreover, the application of domestic tools is mainly driven by marketing instead of sound cost-effectiveness evaluations.

Oropouche Fever, Cuba, May 2024

Oropouche Fever, Cuba, May 2024

CDC Emerging Infections (@CDC_NCEZID) on X

Biting midges are small flies that can spread #Oropouche virus. Many commonly used widow and door screens do not have holes small enough to prevent biting midges from getting inside. Learn more about how to prevent bites https://t.co/4fUMJJN4q2

The First Isolation of Insect-Specific Alphavirus (Agua Salud alphavirus) in Culex (Melanoconion) Mosquitoes in the Brazilian Amazon

Advances in diagnostic techniques coupled with ongoing environmental changes have resulted in intensified surveillance and monitoring of arbovirus circulation in the Amazon. This increased effort has resulted in increased detection of insect-specific viruses among hematophagous arthropods collected in the field. This study aimed to document the first isolation of Agua Salud alphavirus in mosquitoes collected within the Brazilian Amazon. Arthropods belonging to the family Culicidae were collected within a forest fragment located in the Environmental Protection Area of the metropolitan region of Belem. Subsequently, these specimens were meticulously identified to the species level. Afterward, the collected batches were macerated, and the resulting supernatant was then inoculated into C6/36 and Vero cell cultures to facilitate viral isolation. The presence of arboviruses within the inoculated cell cultures was determined through indirect immunofluorescence analysis. Furthermore, positive supernatant samples underwent nucleotide sequencing to precisely identify the viral strains present. Notably, a batch containing Culex (Melanoconion) mosquitoes was identified to be positive for the genus Alphavirus via indirect immunofluorescence. This study is the first report on insect-specific alphavirus isolation in Brazil and the first-ever description of Agua Salud alphavirus isolation within Amazon Forest remnants.