Abstract A strain of C. maculatus was obtained from Turkey where it was collected from lentils. It was transferred to and maintained on cowpeas, the primary host of the species, for 9 generations. The fecundity of females reared in cowpeas was greater than those reared in lentils although, initially, percentage survival and the time for development were comparable in lentils to those exhibited by a Brazilian strain in its normal host, cowpeas. However, the number of eggs laid on lentils rapidly diminished, percentage survival of larvae decreased and the development time increased. The Brazilian strain laid relatively few eggs on lentils compared with the number laid on cowpeas; few of the larvae emerging from those eggs on lentils produced adults and their development time was very long. It therefore appears that strains are well adapted to their normal hosts but have the capacity to move to and utilize new hosts effectively in the course of a few generations.