EVALUATING PREY PREFERENCE BY SEVERAL PHYTOSEIID PREDATORS FOR MONONYCHELLUS-TANAJOA (BONDAR) AND M-CARIBBEANAE MCGREGOR (ACARI, TETRANYCHIDAE) IN CASSAVA

Five phytoseiid predators from the dry regions of Colombia and Ecuador , which are candidate classical biological control agents of the cassa va green mite, were evaluated for preference of the predominant indige nous prey, Mononychellus caribbeanae McGregor, and the target prey, Mo nonychellus tanajoa (Bondar). Preference by adult female phytoseiids w as measured in two-choice, split-leaf-disk experiments using four para meters: consumption of prey eggs, consumption of prey immatures, locat ion of phytoseiid eggs, and periodic observations of the location of t he foraging adult female phytoseiid. None of the phytoseiid species sh owed any preference with respect to the consumption of prey tetranychi d eggs. Galendromus helveolus Denmark, Neoseiulus californicus (McGreg or), and Neoseiulus idaeus Denmark and Muma showed substantial prefere nce for M. tanajoa. Typhlodromalus tenuiscutus McMurtry & Moraes was t he only species that failed to show a preference for either tetranychi d for any of the parameters. Typhlodromalus manihoti (Moraes) showed a preference only for M. tanajoa immatures. None of the phytoseiids exh ibited a preference for M. caribbeanae in any of the assays, so they c an all be considered suitable biological control candidates with respe ct to preference for these two prey species, The results are compared with results from previously published olfactometer studies. (C) 1996 Academic Press, Inc.