Evaluating Prey Preference by Several Phytoseiid Predators forMononychellus tanajoa(Bondar) andM. caribbeanaeMcGregor (Acari: Tetranychidae) in Cassava

Five phytoseiid predators from the dry regions of Colombia and Ecuador, which are candidate classical biological control agents of the cassava green mite, were evaluated for preference of the predominant indigenous prey,Mononychellus caribbeanaeMcGregor, and the target prey,Mononychellus tanajoa(Bondar). Preference by adult female phytoseiids was measured in two-choice, split-leaf-disk experiments using four parameters: consumption of prey eggs, consumption of prey immatures, location of phytoseiid eggs, and periodic observations of the location of the foraging adult female phytoseiid. None of the phytoseiid species showed any preference with respect to the consumption of prey tetranychid eggs.Galendromus helveolusDenmark,Neoseiulus californicus(McGregor), andNeoseiulus idaeusDenmark and Muma showed substantial preference forM. tanajoa. Typhlodromalus tenuiscutusMcMurtry & Moraes was the only species that failed to show a preference for either tetranychid for any of the parameters.Typhlodromalus manihoti(Moraes) showed a preference only forM. tanajoaimmatures. None of the phytoseiids exhibited a preference forM. caribbeanaein any of the assays, so they can all be considered suitable biological control candidates with respect to preference for these two prey species. The results are compared with results from previously published olfactometer studies.