Sustainable Management of Invasive Species for Small Island Developing States under Changing Climates

Definition and Examples of Invasive Species

Invasive species threaten the ecosystems they occupy. If they become established and expand, they pose a risk of degradation to the invaded habitats and/or suppression or extinction of other species (Kairo, Bibi, Cheesman, Haysom, & Murphy, 2003; IUCN, 2011). These invasives may also affect processes such as the nutrient and water cycles as well as fire regimes. Invasive species are alien, i.e. introduced from the geographic range where they have existed historically into territories which are ecologically/environmentally different and more conducive to their spread (e.g. in the absence of natural enemies and other species that would compete with them for resources). Some indigenous species can also become invasive if abiotic or biotic changes in their habitats, such as extinction of a major competitor or natural enemy, lead to greater availability of space, light or other resources. Species exhibit varying levels of invasiveness which are mainly influenced by environmental factors (CBD, 2013).

Crop related invasive species (IS) include, insects, viruses, microbes, protists, fungi, plants and animals. Through its association with human activity insects have become frequent invaders. Several invasive alien species (IAS) are associated with host organisms as predators or parasites; the hosts or vectors may be non-invasive but can carry pests or diseases that become invasive in new environments (Moutou & Pastoret, 2010). Most invasive species recorded in SIDS are not pests of agricultural crops, however many invasive pests have been introduced and established in islands, resulting in high economic cost to the agriculture sector.

Some examples include:

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  Arthropods

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  Sucking pests and disease vectors

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    Asian citrus pysllid, Diaphorina citri

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    Brown citrus aphid, Toxoptera citricida (Kirkaldy)

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    Citrus blackfly, Aleurocanthus woglumi Ashby

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    Citrus leafminer, Phyllocnistis citrella Stainton

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    Coconut whitefly, Aleurodicus pulvinatus(Maskell)

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    Diamondback moth, Plutella xylostella L.

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    Hibiscus (Pink) mealybug, Maconellicoccus hirsutus (Green)

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    Imported red fire ant, Solenopsis invicta Buren

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    Melon thrips, Thrips palmi Karny

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    Papaya mealybug Paracoccus marginatus Williams and Granara de Willink

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    Red palm mite Raoiella indica Hirst

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    Tephretid fruitflies Anastrepha spp.

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    Tropical bont tick, Amblyomma variegatum

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    Whitefly, Bemisia tabaci (Gennadius) (B biotype)

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  Molluscs

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    Giant African snail, (Achatina fulica)

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  Diseases

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    Black Sigatoka, Mycosphaerella fijiensis

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    Citrus Canker, Xanthmonas campestris pv. citri

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    Citrus Greening Candidatus Liberibacter asiaticus

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    Citrus Tristeza virus

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    Frosty Pod of cocoa, Moniliophthora roreri

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    Moko disease, Ralstonia solanacearum

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  Plants

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    Black wattle Acacia mearnsii De Wild.

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    Cogon grass Imperata cylindrica (L.) P. Beauv.

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    Corallita Antigonon leptopus Hook. & Arn.

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    Lantana Lantana camara Hook. & Arn

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    Pink tecoma Tabebuia heterophylla (DC.) Britton

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    Water hyacinth Eichhornia crassipes (Mart.) Solms

(Kairo et al., 2003; Lowe, Browne, Boudjelas, & De Poorter, 2000.)