Avian host-selection by Culex pipiens in experimental trials

Area of Science:

• Vector-borne disease ecology
• Medical entomology
• Wildlife disease surveillance

Background:

• Culex pipiens mosquitoes are primary vectors of West Nile virus (WNV) in the United States.
• Field studies indicate a preference for American robins by Culex pipiens.
• The role of innate host preference in observed feeding patterns requires investigation.

Purpose of the Study:

• To experimentally determine the innate host preference of Culex pipiens.
• To compare the attractiveness of American robins versus European starlings and house sparrows to Culex pipiens.
• To assess the influence of environmental factors on mosquito host selection.

Main Methods:

• Host preference trials were conducted in outdoor cages using known numbers of adult female Culex pipiens.
• Mosquitoes were offered a choice between American robins and either European starlings or house sparrows.
• Logistic regression analysis was used to evaluate host choice and influencing factors.

Main Results:

• Culex pipiens were significantly more likely to enter traps baited with American robins compared to European starlings (OR=3.06) or house sparrows (OR=1.80).
• No difference in trap entry was observed when two American robins were offered.
• Mosquito age, bird characteristics, and environmental conditions did not affect host preference.

Conclusions:

• Culex pipiens exhibit an inherent preference for American robins.
• Innate host preferences likely play a significant role in the enzootic transmission of West Nile virus.
• Understanding these preferences is crucial for predicting and managing WNV outbreaks.