Seychelles: Setting up biological control against coconut whitefly

The coconut whitefly Aleurotrachelus atratus Hempel (Hemiptera: Aleyrodidae), has caused significant economic damage to the Comoros in recent years. With the establishment of a biological control program (2005-2007) under the PRPV(collaboration CIRAD / INRAPE), and the discovery of a new species of parasitoid (see summary of the scientific article), the phytosanitary situation in the Comoros has improved significantly.

This experience has been enhanced with the launch of a similar program in the Seychelles, where the whitefly was first reported in January 2007.

At the request of the Seychelles government, a Cirad Entomological mission confirmed inJuly 2007 the presence of the insect on the main island (Mahé), and identifiedan outbreak on the island of Praslin. This whitefly secretes large quantitiesof honeydew which leads to the development of sooty mold on the leaves oftrees. They represent a serious threat to tourism and palm trees in the Seychelles.

In April2008, a biological control project was proposed by Cirad Réunion, in collaboration with the Seychelles authorities. The Seychelles Ministry of Foreign Affairs and the Ministry of the Environment and Transport welcomed thisproject, which is being subsidized by the Fund for Regional Cooperation(France), which has provided some of the funding, the rest being shared between the government of Seychelles and the Territorial Cooperation Programme of the European Union.

Under the first phase of the project, which aims to establish a precise assessment of the situation in the Seychelles, Nicolas Borowiec, entomologist at the UMR PVBMT(CIRAD / University of Réunion), in charge of the project, conducted a missionto the Seychelles in July 2008 accompanied by two technicians.

Preliminary results from this mission showed that the whitefly has spread to La Digue and that four of six palm species endemic to the Seychelles are at risk from this pest. In addition, a newly-discovered parasitoid was found on three islands. It remains to be seen whether this parasitoid is effective in controlling whitefly populations or whether to use one already present in Réunion and the Comoros.The activities planned later in the project aim to answer these questions.

The Seychelles authorities, appreciative of the rapid intervention against this pest, have provided extensive media coverage (television and print) of there cent conference organized on the subject, which was attended by 80 people.