BLOOD-FEEDING PATTERNS OF ANOPHELES FREEBORNI AND CULEX TARSALIS (DIPTERA, CULICIDAE) - EFFECTS OF HABITAT AND HOST ABUNDANCE

The blood feeding patterns of Anopheles freeborni Aitken and Culex tar salis Coquillett were studied, and the effects of host availability on these patterns were assessed in four different habitats within a nort hern California rice agroecosystem Resting mosquitoes were collected f rom June to September of 1991 and 1992. The source of mosquito blood m eals was identified with the modified precipitin test. Anopheles freeb orni exhibited a 'specialized' (fixed) blood feeding pattern, predomin antly (99% of the time) feeding on mammalian hosts; leporids and bovid s were the major hosts, while equines, suids, and other mammals were m inor hosts. Culex tarsalis exhibited a more 'generalized' (catholic) b lood feeding pattern, taking blood meals from both birds and mammals a t a ratio of 3:1 with Passeriformes being the most fed upon host group . Human blood indices were under 3% for both mosquito species, and mul tiple blood meals were estimated at less than 2%. The host feeding pat terns for both mosquito species differed among the four (riparian, ric e, pasture and mixed) habitats. The host feeding pattern for C. tarsal is reflected the distribution of both mammalian and avian hosts availa ble. On the contrary, the host feeding patterns for A. freeborni refle cted the distribution of mammalian but not the available avian hosts. Overall, host availability may be an important determinant of populati on size of some mosquito taxa (e.g. A. freeborni) than others (e.g. C. tarsalis) in rice culture agroecosystems.