forest. I. Baits ranked by numbers of mosquitoes caught and engorged

In an attempt to define *the Favoured hosts of Culex portesi Senevet & Abonnenc and C. taeniopus D. & K., one bat, ten rodents, Four mar-supials,,two birds and one crustacean, one amphibian and one reptile were exposed in groups of six in suction #traps located,in a Forest in Trinidad. Each group of six baits included two whi*te mice as a standard. The numbers of mosquitoes caugh $ at each bait on three or six replicalte exposures were analysed by an analysis of variance #to separate population and site variations. Baits were then compared For ‘ attractiveness ’ by ranking according to an adjusted mean catch For each mosquito species. Tlhe proportion of each mosquito species that engorged on individual baits was also determined. In some cases, attraction and engorgement varied widely, and this was attributed to defensive a&ion on the part of the bait animal. It was concludd that C. faeniopus was particularly attracted by the opossum Didelphis, which was superior to all indigenous mammals, while C. portesi was attracted to a wide range of rodents and marsupials. Neither was attracted by the cold-blooded animals. Both mosquitoes engorged,well on the relatively insensitive marsupials with long bare tails, Didelphis, Marmosa and Caiuromys, and also on the well-Furred *but diurnal squirrel. OF,the mainly nocturnal remainder, Culex portesi showed higher engorgement rates than C. taeniopus, suggesting a more aggressive or persistent Feeding behaviour