The generalist phytoseiid mite Cydnodromus californicus (McGregor) (Mesostigmata Phytoseiidae) is considered a very important
biocontrol agent of the spider mite Tetranychus urticae Koch both in greenhouses and field. Its capacity to feed alternative
foods allows the increase of the population in field, even when the primary prey is not available. To investigate the effect of various
alternative food substances present in the Mediterranean agroecosystems on the biological parameters of C. californicus, laboratory
trials were carried out using 17 pollens and 3 preys. As it was expected, T. urticae was the best food for both the postembryonic
development and the oviposition rate (100% of attained adulthoods and 2.65 eggs/female/day were laid). Good results
were obtained also with pollens of Carpobrotus edulis (L.) and Scrophularia peregrina L.: on both pollens, 84% of eggs reached
the adulthood and the oviposition rate was 2.00 and 1.81 eggs/female/day for the two pollens respectively. Interesting results were
obtained with the alternative prey Petrobia hartii (Ewing), very common on Oxalis spp., a weed widespread in Mediterranean orchards
(72% of attained adulthoods and 0.57 eggs/female/day). On the other hand, the effect of Mentha piperita L. was not positive
on the juvenile development (only 28% of eggs reached the adulthood), while it was positive on the oviposition rate (1.12
eggs/female/day)