• Pests in brief

Being given their characteristics, the islands of the south west of the Indian Ocean have favourable conditions for the introduction and propagation of harmful organisms (insularity, diversity of ecosystems, vacant ecological niches ...).

Trade and the development of communication networks between the different states of the Indian Ocean region have allowed disease organisms to cross the natural barriers. Numerous species can thus be found in several countries of the Indian Ocean :

• like the melon fly, Bactrocera cucurbitae, which is harmful to Cucurbitaceae in Mauritius, Réunion and Seychelles
• or, furthermore, the Ralstonia solanacearum bacterium which causes severe damage to solanaceous crops and for which no curative means exist for the time being.

Very often a non-invasive organism in an ecosystem can become invasive in another. The introduction of Hoplochelus marginalis (still called white grub) in Réunion in the 70s bears witness to that. This beetle’s larva, endemic to Madagascar, has caused important damage to sugarcane in the 80s. Its negative effects and its propagation have been contained thanks to the introduction of an entomopathogenic fungus of the Beauveria specie, an accessory to biological control also from Madagascar.

A number of insects are still restricted to certain countries of the Indian Ocean. Those harmful organisms constitute quarantine insects against which one must be protected through th implementations of phytosanitary regulations.

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