In comparative tests with baited traps slowly rotated about a common vertical axis, comparable numbers of Culex tarsalis were attracted to birds of the same size whether of the same or different species, while the number attracted to birds of different size was proportional to their size.
C. tarsalis engorgement rates were independent of attraction rates and size of bird, but they varied for different bird species and for different individuals of the same species. Engorgement rates on individual birds were usually consistent, with only a few instances of night-to-night differences. A combination of the host's attractiveness and acceptability to C. tarsalis undoubtedly influences the biting attack rates on avian hosts.
A depression of the engorgement of C. tarsalis on chickens was found to be correlated with increased numbers of mosquitoes.
C. tarsalis is attracted to and feeds on a wide range of avian and mammalian species exposed in traps under field conditions.
Logan Field Station Section, Communicable Disease Center, Logan, Utah.
School of Public Health, University of California, Berkeley.
Communicable Disease Center, Bakersfield, California.