Overabundant single‐host settings as field labs to assess blood meal patterns of mosquitoes

Abstract

Blood meal patterns of mosquitoes (Diptera: Culicidae) are strongly influenced by hostavailability. However, the role of community composition and abundance of vertebratehosts in determining such patterns is still unclear. Here, we analysed the blood mealsources of field-collected mosquitoes in settings with a permanent overabundance of aspecific vertebrate species. Mosquitoes were collected using a battery-powered handheldaspirator every 2 months between November 2021 and April 2022 in temperateArgentina. Blood-engorged mosquitoes were collected at 11 sites corresponding to fivetypes of settings: two cattle fields, one rabbit breeding farm, three chicken farms, twodog boarding facilities, and three geriatric hospitals, characterised by the permanentoverabundance of cows, rabbits, chickens, dogs, and humans, respectively. Blood mealanalysis was performed via polymerase chain reaction (PCR) and sequencing. A principalcomponent analysis (PCA) was performed in which variables were pairs comprising anengorged mosquito species and the host species it fed on. A total of 242 blood mealsfrom Aedes (3 species), Culex (4), Isostomyia (1) and Psorophora (1) were identified. Amongthese, five mammals and 12 avian species were identified as hosts. Overall, 79% of theblood meals were taken from the overabundant host, ranging from 67% to 99% in all settingsexcept for geriatric hospitals (7%). The proportion of feeds taken on the overabundanthost was lowest for Culex quinquefasciatus Say (0.67, N = 119), Cx. pipiens molestusForskal (0.5, N = 18) and the hybrid between the two (0.5, N = 2), and highest for Aedesaegypti Linnaeus (1, N = 2), Ae. albifasciatus Macquart (1, N = 3), Ae. crinifer Theobald(1, N = 46), Cx. eduardoi Casal & García (0.9, N = 10), Isostomyia paranensis Brèthes(1, N = 20) and Psorophora ferox Humboldt (1, N = 21). By fixing host abundance in preselectedsettings, we propose a field design that overcomes the difficulties of estimatinghost community composition. This approach aids in achieving a clearer understanding ofmosquito feeding patterns and their implications for arbovirus disease transmission.