Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Definitions used in the Invasive Species Compendium

The following working definitions have been applied during the development of this compendium.

Species categorizations

Invasive (alien) species: an (alien) species whose establishment and spread threaten ecosystems, habitats or species with economic or environmental harm.
Source: McNeely, J.A., Mooney, H.A., Neville, L.E., Schei, P.J. and Waage, J.K. (eds) (2001) Global Strategy on Invasive Alien Species. IUCN, Gland, Switzerland and Cambridge UK. [Use of the term "species" in this context includes species, subspecies or lower taxa; also note parentheses have been added around 'alien' by CABI because the Compendium also considers species that are invasive in their native range].

Introduced species (alien, non-native): A species, subspecies or lower taxon, introduced outside its natural past or present distribution; includes any part, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce.
Source: CBD Guiding Principles

Native species: A species, subspecies, or lower taxon, occurring within its natural range (past or present) and dispersal potential (i.e. within the range it occupies naturally or could occupy without direct or indirect introduction or care by humans.)
Source: IUCN, 2000. IUCN Guidelines for the Prevention of Biodiversity Loss caused by Alien Invasive Species. IUCN, Species Survival Commission, Gland, Switzerland.

(Plant) pest: Any species, strain or biotype of plant, animal or pathogenic agent injurious to plants or plant products.
Source: FAO, 2007. Glossary of Phytosanitary Terms. ISPM Pub. No. 5. FAO, Rome, Italy.

OIE notifiable disease: Detailed criteria for inclusion of diseases in the list of those notifiable to the World Organisation for Animal Health (OIE) are given in Chapter 2.1.1. of the Terrestrial Animal Health Code (OIE, 2007). Each criterion is based on a measurable parameter, and if a disease fulfills at least one of these, it becomes notifiable. Potential for international spread is the most important criterion. Others include zoonotic potential and the ability to spread significantly within native populations.

Distribution categories

The distribution status for a country or region is based on all the information available - when several references are cited in the Distribution Table or map, they may give conflicting information on the species status. In particular, citations of earlier presence may be included even though there is an authoritative reference to indicate that the pest is now absent. An alternative view of the distribution records is provided in the datasheet report where the section 'Distribution Table Details' can be selected to display each referenced source as a row in table format. In some cases extra information concerning individual sources can be found there. This section is not provided by default when the Report option 'All sections' is selected because the more compact 'Distribution Table' is used in preference. It can be manually selected for inclusion in the datasheet report.

Only records of presence are shown in the default display of the distribution map. Please refer to the Distribution Table in the datasheet for records of eradications, former presence, interceptions, and unreliable or invalid records reported in the literature. The absence of a record on the map does not necessarily mean the pest is absent from that country or region, it may be the case that information for those areas is not available. Most distribution records arise from a report of presence at some time in the past; it is not within the scope of Compendia to seek absence records routinely. The Distribution text in the datasheet may also provide additional information.

CABI requests users to send additional distribution information, with appropriate published references, to the Compendium Coordinator, CABI, Wallingford, Oxon OX10 8DE, UK, email: Only records accompanied by a published reference can be considered for inclusion but personal communications may be recorded in the text until a published record becomes available. Data will be verified by CABI's scientific advisors, but this process will be greatly assisted if the relevant references are provided.

Categories of presence

Present (no further details): Occurring in a particular country or area (without details on range). May be abbreviated to 'Present'
Widespread: Occurring practically throughout the country or area where conditions are suitable
Restricted distribution: Present, but not widespread; used to indicate that the species does not occur in some suitable parts of the country or area. Other terms used for the same situation are: "Localised" and "Limited distribution"
Present, few occurrences: Reported occasionally or reports suggest its presence is rare or sporadic
Present only under cover/indoors
Present only in captivity/cultivation: It is not intended that pet, zoo, aquarium, botanical garden and ornamental occurrences are generally included in the Distribution Table, however this category may be the most appropriate for some records selected for inclusion. Occurrence in captivity and cultivation is more concisely described in the Distribution text
Confined and subject to quarantine: Confined to a particular area only and prevented from spreading to other parts of the country or area by regulatory control (quarantine) and official measures are taken to control or eradicate the pest within the confined area

The following FAO categories for plant pest reporting have been added to the Compendium:
Transient: actionable, under eradication: The pest has been detected as an isolated population which may survive into the immediate future and, without phytosanitary measures for eradication, may establish. Appropriate phytosanitary measures have been applied for its eradication
Transient: actionable, under surveillance: The pest has been detected as an individual occurrence or an isolated population that may survive into the immediate future, but is not expected to establish. Appropriate phytosanitary measures, including surveillance are being applied
Transient: non actionable: The pest has only been detected as an individual occurrence or isolated population not expected to survive and no phytosanitary measures have been applied

Categories of absence

Eradicated: Recorded at some time in the past but eradication was successful, so the pest is not present now
Absent, intercepted only: Only found in imported consignments, on entry or at the place of destination. It is not present now
Absent, formerly present: Recorded at some time in the past, but did not establish and is not present now. It disappeared without any special measures being taken
Absent, unreliable record: Species records indicate presence but they are considered unreliable because of ambiguous nomenclature, outdated identification methods etc.
Absent, invalid record: Species records indicate presence but the records are no longer valid due to changes in taxonomy, misidentification, erroneous record, changes to national borders etc.
Absent, never occurred: The country concerned officially states that the species has never occurred there. This category is not used comprehensively, usually only if there has been an incorrect report in the literature

For animal diseases, the categories used in data supplied by the OIE include:
Disease never reported
Disease not reported (date of last outbreak not known)
Disease last reported in [Date of the last reported occurrence of the disease in previous years]
Disease suspected but presence not confirmed
Reported present or known to be present
Serological evidence and/or isolation of the causal agent, but no clinical signs of disease
Disease limited to specific zones

Pathways for introduction and dispersal

Pathway cause: Why a species is transported, that is, whether accidentally or deliberately
Pathway vector: How, physically, a species in transported, that is, the physical means or agent
Carlton JY, Ruiz GM, 2005. Vector science and integrated vector management in bioinvasion ecology: conceptual frameworks. In: Invasive Alien Species: A New Synthesis (ed. by Mooney HA et al.). Island Press, Washington, USA.

It is acknowledged that the scheme now widely accepted by invasive species data publishers is that described in the technical note Convention on Biological Diversity (CBD), 2014. Pathways of introduction of invasive species, their prioritization and management (26 June 2014; It is CABI’s intention to apply this more recent schema to the data in the ISC datasheets and the Horizon Scanning Tool