de Silva, P.H.P.R.Fernando, L.C.P.2014-05-162014-05-162008Exp Appl Acarol (2008) 44:37–42http://hdl.handle.net/123456789/1358A method was developed for the rearing of coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), and its predatory mite Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae) on embryo culture seedlings of coconut (Cocos nucifera) in the laboratory. Seedlings in the ages of <2, 2–4 and 4–6 months were infested with 75 Weld- collected coconut mites and the population growth was determined up to six weeks after introduction. The populations of coconut mites increased exponentially up to Wve weeks after introduction and declined thereafter on seedlings of all ages with signiWcant diVer- ences among the three groups of seedlings occurring over time. At week 5, a signiWcantly higher mean number (§SE) of coconut mites (20,098 § 3,465) was bred on 4–6-month-old seedlings than on smaller seedlings, and on the largest seedlings the numbers were highest at all time intervals, except at week 2. Neoseiulus baraki was reared on embryo culture seedlings of the three age groups infested with coconut mites, by introduction of Wve female deutonymphs and one male, three weeks after introducing coconut mites. Predator numbers progressed signiWcantly over time, but the size of seedlings did not signiWcantly inXuence the numbers. On all groups of seedlings, the mean number of N. baraki increased up to two weeks after introduction on to seedlings and then declined. Many coconut mites were successfully reared in the laboratory for a longer period by this method and it could also be used as an alternative method to rear N. baraki. Development of this method may contribute to the progress of studies on the biology and ecology of coconut mite and its interactions with natural enemies.enAceria guerreronisCocos nuciferaCoconutNeoseiulus barakiRearingArticle