Feeding Ecology and Host Preferences of Mosquitoes in two Zoological Gardens in the United Kingdom

Abstract Background: Zoological gardens contain unique configurations of exotic and endemic animals and plants that create a diverse range of developing sites and potential sources of blood meals for local mosquitoes. This may imply unusual interspecific pathogen transmission risks involving zoo animals, like avian malaria to captive penguins. Understanding mosquito ecology and host preferences is necessary to improve mosquito control and disease prevention measures in these environments. Methods: Mosquito sampling took place in Chester Zoo for three years (2017 to 2019) and for one year in Flamingo Land (2017) using different trapping methods. Blood-fed mosquitoes were identified and their bloodmeal was amplified by PCR, sequenced, and blasted for host species identification.Results: In total, 640 blood-fed mosquitoes were collected (Culex pipiens (n = 497), Culiseta annulata (n = 81), Anopheles maculipennis s.l. (n = 7), An. claviger (n = 1) and unidentifiable (n = 55)). Successful identification of the host species was achieved from 159 of the 640 blood-fed mosquitoes. Mosquitoes fed on birds (n = 74), non-human mammals (n = 20) and humans (n = 71). There were mixed bloodmeals from two hosts (n = 6). The proportions of blood-fed mosquitoes varied across sampling seasons and sites within the zoos. The use of resting traps and aspiration of vegetation were more efficient techniques for capturing blood-fed mosquitoes than traps for host-seeking or gravid mosquitoes. By relating the locations of zoo animals to where fed mosquitoes were trapped, the minimum travelling distances were calculated (13.7 to 366.7 meters). Temperature, precipitation, relative humidity, proximity to zoo animal exhibits and vegetation level were found to be significantly associated with the proportion of captured blood-fed mosquitoes by generalized linear modelling.Conclusions: Mosquito feeding behaviour in zoos is influenced by environmental variables and host availability, which highlights the value of mosquito monitoring in complex settings to plan control strategies and potentially reduce inherent disease transmission risks for humans and threatened zoo animals.