The use of an animal-baited net trap for collecting mosquitoes during western equine encephalitis investigations in Argentina.

The research article describes a study conducted in Argentina on mosquito populations using a large net trap baited with horses, during an outbreak of western equine encephalitis in 1984. The research also explores the use of this trapping method for studies on arbovirus ecology.

Sampling Method and Locations

• The study involved setting up a large net trap around horses to catch mosquitoes at three different locations each in Santa Fe and Rio Negro Provinces of Argentina.
• The research was conducted during the austral summer of 1984, following a severe outbreak of western equine encephalitis (WEE) across different provinces in Argentina in 1982-83.

Results and Findings

• From the study, a total of 2,752 mosquitoes were collected from Santa Fe province over five trap nights whereas Rio Negro witnessed a collection of 6,929 mosquitoes over three trap nights.
• In Santa Fe, Culex mosquitoes of the Culex subgenus were the most common, making up 45.8% of the total collection. Aedes albifasciatus mosquitoes were also prevalent, with a ratio of 21.7%.
• In Rio Negro province, the most common species of mosquito was the Aedes albifasciatus, making up 95.7% of the total collection.
• The complexity and diversity of mosquito fauna were found to be higher in Santa Fe Province (with a minimum of 18 species) compared to Rio Negro province (with a minimum of 6 species).

Implications and Recommendations

• The outcomes of the study indicate the usefulness of the net trap in arbovirus ecology studies. It can be an effective tool to assess the diversity and population of mosquitoes in a particular region, which can help in controlling the spread of diseases they might carry.
• Given the high effectiveness of the large net trap, the authors recommend its use in other regions for similar studies, especially in areas where arboviral diseases are prevalent.