UK Overseas Territories

UK Overseas Territories Programme

Inspecting Scaevola sericea on Anegada, British Virgin Islands

Weed and pest problems in the UKOTs

Within many of the UKOTs, introduced exotic species of animals and plants pose an enormous threat to survival of native species.People settling on the islands brought useful crop plants with them to provide food, fuel or fibres. Once in their new environment, away from their natural pests which kept their growth in check, some of these species spread rampantly and smothered indigenous plants.

Exotic invasives: the discovery of Scaevola sericea on Anegada

During fieldwork on Anegada (British Virgin Islands) for the Darwin Initiative project, 'An Assessment of the Coastal Biodiversity of Anegada', the project team discovered several specimens of an exotic invasive shrub, Scaevola sericea (Goodeniaceae).

Originally from the Indo-Pacific region, this species was introduced into Florida and the Caribbean as a landscaping plant and for stabilising sand dunes. In south Florida, S. sericea has become established on many coastal shores, competing with and displacing native vegetation. With buoyant fruit adapted for ocean dispersal and seed which remains viable in sea water, S. sericea was probably carried to Anegada from the Lesser Antilles on ocean currents. It could also have been dispersed by sea birds from neighbouring islands such as Tortola, where the species is used as a landscaping plant. It is more robust and aggressive than the inkberry (S. plumieri), Anegada’s native species of scaevola.

The project team is monitoring the spread of Scaevola sericea on Anegada and asking the local community to help by reporting new localities to the National Parks Trust. To assist in field identification, we have produced a poster and a monitoring form to help distinguish the native species from the exotic.

The invasive Scaevola sericea

Pest problems – an invasive scale insect
Die-back caused by pine scale

In 2005, Kew conservation staff working with the Turks and Caicos National Trust discovered an invasive scale insect, the pine tortoise scale (Toumeyella parvicornis), feeding on the native pine tree, Pinus caribea. This was of particular concern because it is the first time this insect has been detected in the Caribbean. The insect, which is a forestry pest in North America, sucks the sap of various pine trees. It causes greatest harm to seedlings and young saplings which become covered with a black sooty mould. Sometimes infestation can kill branches or even whole trees. The presence of the scale insect will be carefully monitored to assess the level of infestation.

Find out more about weed and pest problems in the UKOTs:

Global Invasive Species Programme
JNCC report on Non-native species in the UK Overseas Territories: a review

 Project: Assessment of the Coastal Biodiversity of Anegada, BVI