Terms of reference

Following an application to import the currently un-regulated pest Agrotis infusa for research purposes in Sweden, the Swedish Board of Agriculture has requested SLU Risk Assessment of Plant Pests to perform a rapid PRA of the species. The PRA should provide a description of the pest and focus on the likelihood of establishment, potential magnitude of spread and potential impact and whether the corresponding criteria for a quarantine pest could be fulfilled. The risk assessment area is Sweden, but within the context of the whole EU. The format of this rapid PRA is an adapted version of the EPPO Express PRA scheme (EPPO 2012; 2019).

Summary

Agrotis infusa, with the common names Bogong moth or Common cutworm, is a nocturnal moth native to Australia. The species is well known for its annual long-distance migrations from the breeding areas to the Australian Alps where the moth hibernates during the summer, referred to as aestivation. The species is a very polyphagous pest and feeds on a range of different plants including species of cereals, vegetables, grasses, legumes, weeds as well as pine seedlings.

Presence

Agrotis infusa is native in Australia and has not been reported as established anywhere else. The moth is frequently observed in New Zealand but has not established populations there.

Entry, establishment and spread

The likelihood of entry was not evaluated since the PRA was initiated as a response to an application to import A. infusa. The likelihood of establishment in Sweden was assessed as very low (with medium uncertainty) mainly due to unfavourable climatic conditions. In the southern and western parts of the EU, where the climate is comparable to that in the native range and host plants are available, the likelihood of establishment is assessed as higher than in Sweden. If A. infusa establish in more southern parts of the EU, annual migration of the pest into Sweden could occur. Agrotis infusa is able to disperse very long distances but potentially strong Allee effects may reduce the spread rate. If established, the magnitude of spread was assessed as high with medium uncertainty.

Impact

Damage by Agrotis infusa is caused by larval feeding and many host plants in the native range are also found in Sweden and the EU. The magnitude of potential impact in Sweden was assessed as very low (with low uncertainty) mainly due to unfavourable climatic conditions.  At the EU-level the endangered area would be regions in western and southern parts of the EU where climatic conditions are conducive and host plants are available. The potential impact in these areas would presumably be similar to that in the native range, i.e. moderate economic impact with medium uncertainty, low environmental and social impact with medium and low uncertainty respectively. 

Assessment in relation to the definition of a quarantine pest

The following conclusions were made in relation to the conditions required for a quarantine pest (EU 2016/2031);

(a) Agrotis infusa is a plant pest whose identity is established

(b) Agrotis infusa is not present in the EU.

(c) Whether A. infusa is capable of entering into the EU was not assessed since the PRA was initiated as a response to an application to import the species for research purposes. Following potential entry, the likelihood of establishment in Sweden was assessed as very low and the criteria of being capable of becoming established is assessed to not be fulfilled. The likelihood of establishment was assessed to be higher in some other parts of the EU but further analysis would be required to determine if the criteria of establishment at the EU-level is fulfilled.

(d) A detailed description of the current impact of A. infusa, and an assessment of potential impact in Sweden/EU is provided in this PRA to support a decision of whether the potential impact should be considered to be “unacceptable”.

(e) Whether effective measures are available to prevent the entry of A. infusa was not assessed since this PRA was initiated as a response to an application to import the species for research purposes.

Key uncertainties and further investigation needed

The main uncertainty is associated with the potential establishment of A. infusa. In particular, there is a lack of information about the climatic requirements for non-migratory populations of the pest and whether other factors prevent establishment outside the native range, e.g. strong Allee effects. There is also a lack of quantitative estimates of damage in the literature. Further analysis is needed to improve the assessment of the endangered area in the EU.