Exploring the ecological surveillance of mosquito vectors and arbovirus threats in one of Brazil's most biodiverse protected areas
Deep within the dense Atlantic Forest of Brazil's Rio de Janeiro state, the Parque Estadual dos Três Picos (PETP) stretches across more than 65,000 hectares of pristine wilderness. As the largest state park in Rio de Janeiro, it serves as a crucial biodiversity sanctuary, protecting countless species of flora and fauna in one of the world's most threatened ecosystems 4 . With its imposing granite peaks reaching heights of 2,366 meters, spectacular waterfalls, and lush vegetation, the park represents both a natural treasure and an important ecotourism destination. Yet, beneath this breathtaking landscape, an invisible drama unfolds—one that connects the health of the forest to the health of human populations.
Mosquitoes play critical roles in forest ecosystems as pollinators, food sources, and nutrient cyclers, despite their potential as disease vectors.
These insects pose potential threats as vectors of diseases known as arboviruses—including dengue, yellow fever, chikungunya, and Zika 1 .
Within this protected area, scientists have turned their attention to some of the forest's smallest inhabitants: mosquitoes. Far from being merely nuisance biters, these insects play critical roles in ecosystem dynamics while simultaneously posing potential threats as vectors of diseases known as arboviruses. Research conducted in the park aims to unravel the complex interactions between these mosquitoes, their environment, and the pathogens they might carry 1 . This investigation isn't just academic; it's a crucial step in preventing outbreaks of dangerous diseases in both wildlife and human populations who live near or visit these protected areas.
To understand the potential disease threats lurking within the forest, researchers designed a comprehensive study that combined field ecology with meticulous data collection. The investigation, centered around the Jequitibá headquarters area of PETP, established five sampling points along different trails with varying environmental configurations 2 . Each location was carefully selected to represent the diverse habitats found within the park, from dense forest interiors to areas more frequently visited by humans.
Sampling Points
Capture Techniques
Environmental Monitoring
The research team employed multiple capture techniques to get a complete picture of the mosquito populations. For adult mosquitoes, they used CDC light traps baited with CO₂—the carbon dioxide mimicking human breath—and Castro catchers for more targeted collection 1 2 . To capture mosquitoes in their immature stages, scientists scoured natural breeding sites, examining everything from permanent and semi-permanent bamboo stalks to water-filled bromeliads, tree holes, and even rock cavities 1 .
The study extended beyond simple collection, incorporating environmental monitoring to understand what factors influenced mosquito activity. Temperature, relative humidity, rainfall, larval habitat availability, and vegetation cover were all meticulously recorded across different times of day and throughout the seasons 1 . This comprehensive methodology enabled scientists to paint a detailed picture of how ecological factors shape mosquito populations in this protected area.
What researchers discovered was both fascinating and concerning: the park harbored an astonishing diversity of mosquito species, with their presence and abundance directly influenced by environmental conditions 1 . The findings revealed a complex ecosystem where different mosquito species occupied specific niches, their populations fluctuating with seasonal changes and habitat availability.
Among the captured specimens, several species known to be capable vectors of arboviruses stood out. Aedes fluviatilis (71 specimens), Aedes scapularis (55 specimens), and Haemagogus leococelaenus (29 specimens) were all present in significant numbers, along with various species from the Culex genus (163 specimens) 2 .
Perhaps most revealing was how mosquito populations responded to environmental drivers. The research demonstrated that mosquito richness and diversity were directly influenced by factors like temperature, humidity, and rainfall 1 .
| Species | Vector Potential | Abundance | Transmission Risk |
|---|---|---|---|
| Aedes fluviatilis | Arbovirus transmission | 71 specimens | |
| Aedes scapularis | Arbovirus transmission | 55 specimens | |
| Haemagogus leococelaenus | Yellow fever, other arboviruses | 29 specimens | |
| Culex spp. | Various arboviruses | 163 specimens |
The meticulous work of entomological surveillance relies on both traditional tools and modern technology. Each piece of equipment serves a specific purpose in the challenging environment of the Atlantic Forest, where researchers must adapt to difficult terrain and unpredictable weather conditions.
A crucial device that uses light and carbon dioxide to attract host-seeking mosquitoes, particularly effective for capturing a wide diversity of species across different habitats.
A manual capture tool that allows researchers to actively collect mosquitoes from their daytime resting places, complementing the passive trapping methods.
Hands-on approach of inspecting natural containers, from water-filled bromeliads to tree hollows, to identify mosquito breeding sites 1 .
Used for detailed morphological examination of collected specimens, enabling accurate species identification based on physical characteristics.
Specialized guides that lead researchers through a series of choices based on morphological features to correctly identify mosquito species 2 .
Digital mapping technology that helps visualize and analyze the spatial distribution of mosquito species in relation to environmental factors 2 .
Site Selection
Field Collection
Specimen Processing
Identification
Data Analysis
The discovery of multiple mosquito species with known vector potential transforms our understanding of disease risk in protected natural areas. The presence of Haemagogus leococelaenus is particularly significant, as this species has been incriminated in transmission of yellow fever virus in sylvatic cycles 2 . Similarly, the various Aedes species collected have demonstrated capacity to transmit multiple arboviruses in different contexts, raising concerns about the potential for these pathogens to circulate within the park's ecosystem.
This research highlights the delicate balance between conservation and public health. Parks like PETP serve as crucial refuges for biodiversity, including mosquito species that may act as bioindicators of environmental change 1 .
The study specifically noted that the park, with its wide density of vector species, presented itself as a location with high potential for transmission, introduction, and reintroduction of arboviruses 1 .
The global context makes this research even more urgent. As noted by the World Health Organization, chikungunya and other arboviral diseases have caused significant outbreaks worldwide, with the presence of competent Aedes mosquitoes posing a continuous threat of introduction and spread in previously unaffected areas 3 .
The meticulous work of entomologists in Três Picos State Park represents far more than an academic exercise in cataloging insect species. It embodies a proactive approach to public health, one that seeks to understand disease threats at their source before they emerge as outbreaks in human populations. By deciphering the complex relationships between mosquitoes, their environment, and the pathogens they carry, this research provides invaluable insights that could help prevent future arbovirus epidemics.
Human health is inextricably linked to the health of our ecosystems
Critical for both biodiversity preservation and human health protection
As climate change and human expansion continue to reshape our world, the interface between wild ecosystems and human communities becomes increasingly porous. In this context, the continuous monitoring of mosquito populations in protected areas takes on critical importance—not just for the preservation of biodiversity, but for the protection of human health. The work in PETP underscores an essential truth: that human health is inextricably linked to the health of our ecosystems, and that by guarding the gateways where these worlds meet, we protect both nature and ourselves.
The future of disease prevention lies in understanding the ecological dynamics of vectors within their natural habitats.