May 2007. Kiribati asked for information on the cultural and biological control of the taro beetle. Kiribati has only one species of the taro beetle – Papuana uninodis – which is known to be present in Kiribati since the 1930s. Use of insecticides cannot be recommended in Kiribati because of very fragile atoll environment.
Biological control using Metarhizium anisopliae (fungus) against taro beetle was tested in 1997; it showed good control and can persist in the soil for up to 9 months after release. In a few trials, using the fungus with mulch in Lae, PNG, it showed up to 90% beetle control and 70-90% clean taro. In fact, the fungus works well in soil with good organic matter.
In the Kiribati situation, two things may work, if:
1. The fungus is applied during planting, and the taro field is kept under mulch throughout the cropping cycle. (Exposing the fungus to direct sunlight reduces virulence; mulching prolongs virulence and persistence.) 2. Taro can be planted in shallow water, for some varieties to avoid taro beetle.
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