|Smith, Lincoln - Link|
Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/4/2001
Publication Date: 12/15/2001
Citation: Cuellar, M., Calatayud, P., Melo, E.L., Smith, L., Bellotti, A.C. 2001. Consumption and oviposition rates of six phytoseiid species feeding on eggs of the cassava green mite Mononychellus tanajoa (Acari:Tetranychidae). Florida Entomologist. 84:602-607. Interpretive Summary: In Africa, the cassava green mite, Mononychellus tanajoa, is an important exotic pest of cassava, Manihot esculenta. The pest is native to South America, where it is generally not such a serious problem. Predatory phytoseiid mites from South America are being evaluated as potential biological control agents of this alien pest. We evaluated six phytoseiid species by measuring the rate of consumption of hosts and the rate of egg laying, in relation to prey density under optimal laboratory conditions. Euseius ho and Typhlodromalus aripo had the highest consumption rates, consuming up to 93 and 101 pest eggs per day. Prey consumption by Typhlodromalus tenuiscutus, Neoseiulus californicus, Neoseiulus idaeus, and Galendromus annectens was never above 40, and it leveled off at lower prey densities. Typhlodromalus tenuiscutus had the highest oviposition rate (up to 3.9 eggs per day). Galendromus annectens had extremely high oviposition/consumption ratios at the lowest prey densities, suggesting that these species can persist when prey are scarce.
Technical Abstract: We evaluated six species of predatory phytoseiid mites, collected in South America, for their potential as biological control agents for the cassava green mite, Mononychellus tanajoa. We measured the rate of consumption of hosts and the rate of egg laying, in relation to prey density under optimal laboratory conditions. Prey consumption by Euseius ho, Typhlodromalus aripo and T. tenuiscutus were the highest, with maxima of 93, 101 and 59 prey per day, respectively when 200 prey were available. Maximum daily oviposition rates were highest for T. tenuiscutus, N. californicus, N. idaeus and G. annectens (3.9, 3.6, 2.9 and 9.8, respectively). Euseius ho and T. aripo had lower oviposition maxima (2.2 and 1.4, respectively). The ratio oviposition to prey consumption was generally higher for G. annectens, N. californicus and N. idaeus. The high prey consumption rate of E. ho, T. aripo and T. tenuiscutus suggests that these species are the best agents in regard to the attack of pest eggs. The high oviposition/consumption ratio at low prey densities (1-3 prey eggs) of T. aripo and G. annectens suggests that these species may be able to reproduce enough to persist when prey populations are low.