Pest categorisation of Liriomyza sativae

Abstract

The EFSA Panel on Plant Health performed a pest categorisation of Liriomyza sativae (Diptera: Agromyzidae) for the EU. L. sativae (the cabbage or vegetable leaf miner; EPPO code: LIRISA) is a polyphagous pest native to the Americas which has spread to Africa, Asia and Oceania. L. sativae can have multiple overlapping generations per year. Eggs are inserted in the leaves of host plants. Three larval instars, which feed internally on field vegetables (leaves and stems), follow. Then, the larva jumps into the soil where a fourth larval instar occurs immediately before pupation, which takes place in the soil. L. sativae is regulated in the EU by Commission Implementing Regulation (EU) 2019/2072 (Annex IIA). Within this Regulation, import of soil or growing medium as such or attached to plants for planting from third countries other than Switzerland is regulated. Therefore, entry of L. sativae pupae is prevented. However, immature stages on plants for planting (excluding seeds) and fresh leafy hosts for consumption, cut branches, flowers and fruit with foliage provide potential pathways for entry into the EU. L. sativae has been repeatedly intercepted in the EU, especially in basil (Ocimum spp.). Climatic conditions and the wide availability of host plants provide conditions to support establishment in the EU, both in open fields and greenhouses. Impacts on field vegetables and ornamentals as well as hosts in greenhouses would be possible. Phytosanitary measures are available to reduce the likelihood of entry. L. sativae satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest. Although human-assisted movement of vegetables is considered the main spread way for L. sativae, this agromyzid does not meet the criterion of occurring in the EU for it to be regarded as a potential Union regulated non-quarantine pest.

Keywords: Agromyzid; European Union; cabbage leaf miner; pest risk; plant health; plant pest; quarantine; vegetable leaf miner.

Figure 1

Global distribution map for Liriomyza sativae (extracted from the EPPO Global Database updated 30/01/2020 accessed on 17/2/2020)

Figure 2

Host plants where L. sativae was intercepted between 1996 and 2019 (n = 624). Hosts where the pest was intercepted less than 10 times have been grouped as ‘Others’. This category includes Amaranthus sp., Amaranthus viridis, Artemisia dracunculus, Brassica alboglabra, Brassica sp., Cassia sp., Cestrum sp., Chrysantemum sp., Coriandrum sativum, Dendranthema sp., Dianthus sp., Gypsophila sp., Ipomoea sp., Momordica charantia, Moringa oleifera, Solanum sp., Solidago sp., Spinacia sp., Trigonella sp. and Trigonella foenum‐graecum

Figure 3

Countries of origin of the commodity where L. sativae was intercepted between 1996 and 2019 (n = 624). Countries from which the pest was intercepted less than 10 times have been grouped as ‘Others’. This category includes Congo, Colombia, Dominican Republic, Ecuador, Egypt, Ethiopia, Ghana, Iran, Jordan, Sri Lanka, Morocco, Mexico, Nigeria, Pakistan, Tanzania and Uganda

Figure 4

Annual number of interceptions of L. sativae between 1996 and 2019 (n = 624)

Figure 5

Köppen–Geiger climate type zones (MacLeod and Korycinska, 2019). In its native range in the Americas, L. sativae is established from Canada to Argentina and Chile (dotted rectangle), a zone including all climate types also occurring in the EU