Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Oviposition Activity and the Associated Socio-environmental Factors in the New Orleans Area

Mosquito Population Dynamics and Blood Host Associations in Two Types of Urban Greenspaces in Coastal Florida

Urban greenspaces, including residential parks and conservation areas, provide ecological and recreational benefits. This study reports mosquito surveillance and blood meal analysis data from greenspaces in Vero Beach, Florida. It also compares mosquito assemblages and host associations across residential and conservation greenspaces to assess how greenspace type impacts mosquito abundance and host interactions. Using CO2-baited traps and large-diameter aspirators, mosquitoes were collected over 26 sampling weeks (February-December 2023) yielding over 19,000 female mosquitoes from 32 species. Although mosquito species richness and community composition were similar across greenspace types, relative abundance of some key vector and nuisance species differed significantly. For example, Aedes taeniorhynchus was more common in preserved coastal wetland greenspaces, while Aedes aegypti and Aedes albopictus were more common in residential greenspaces. Generalized linear models revealed the impacts of climatic variables on the abundance of many key mosquito species. Blood meal analyses showed that host associations did not vary significantly by greenspace type, suggesting stable mosquito-host interactions across the landscape. These results highlight that greenspaces are not uniform in their mosquito species composition. Further studies on the effects of different greenspace types on mosquito communities can help to identify urban landscape features that minimize mosquito-borne disease risk.

Discarded vehicle tires and their association with mosquito vector abundance across socioenvironmental gradients in New Orleans, LA

Discarded vehicle tires serve as habitat for mosquito vectors. In New Orleans, Louisiana, discarded tires are an increasingly important public concern, especially considering that the city is home to many medically important mosquito species. Discarded tires are known to be associated with mosquito abundance, but how their presence interacts with other socioenvironmental gradients to influence mosquito ecology is poorly understood. Here, we ask whether discarded tire distribution could be explained by social factors, particularly median income, home vacancy and human population density, and whether these factors interact with urban heat islands (UHI) to drive mosquito vector assemblages. We surveyed tire piles across the city and adult mosquitoes in 12 sites, between May and October of 2020. We compared this data with the social indicators selected and UHI estimates. Our results show that median income and human population density were inversely related to tire abundance. Tire abundance was positively associated with Aedes albopictus abundance in places of low heat (LS) severity. Heat was the only predictor for the other monitored species, where high heat corresponded to higher abundance of Aedes aegypti, and LS to higher abundance of Culex quinquefasciatus. Our results suggest that low-income, sparsely populated neighborhoods of New Orleans may be hotspots for discarded vehicle tires, and are associated with higher abundances of at least one medically important mosquito (Ae. albopictus). These findings suggest potential locations for prioritizing source reduction efforts to control mosquito vectors and highlight discarded tires as a potential exposure pathway to unequal disease risk for low-income residents.

Aedes albopictus distribution in Ibagué, Colombia: Potential risk of arboviral outbreaks

Introduction

Aedes albopictus is a vector for arboviruses, such as dengue, Zika, chikungunya, and yellow fever. The first A. albopictus reports on the American continent date back to 1985. It has spread rapidly throughout Colombia since its first report in 1998 due to its ecological and physiological adaptation capability.

Objective

To determine A. albopictus distribution in the 13 communes of Ibagué, Colombia.

Materials and methods

Samples were collected between May and November 2022 in the 13 communes of Ibagué. Vacuum sampling and sweep-netting entomological nets were used in areas with abundant vegetation. The mosquitoes were transported to the Laboratorio de Investigaciones en Parasitología Tropical at the Universidad del Tolima for taxonomic determination.

Results

We identified 708 A. albopictus specimens distributed throughout Ibague’s 13 communes. The highest vector abundance occurred in communes 10, 11, 7, 8, 2, and 9; communes 3, 4, 5, 6, 12, and 13 had a relative abundance of around 3%, while commune 1 had 2% of relative abundance.

Conclusions

Aedes albopictus is distributed throughout all the communes of Ibague. Its dispersion has probably been favored by this region’s environmental and social conditions. We recommend annual monitoring of these vectors populations and molecular characterization of the found arboviruses. Ascertaining this mosquito’s distribution throughout the city will enable focusing entomological control strategies and preventing future arbovirus outbreaks.