Pest categorisation of naupactus leucoloma

Abstract

The EFSA Panel on Plant Health performed a pest categorisation of Naupactus leucoloma Boheman (Coleoptera: Curculionidae) for the EU territory. N. leucoloma is a polyphagous pest reported to feed on 385 plant species; cultivated hosts include alfalfa, beans, brassicas, carrots, clover, onions, peas, potatoes and soft fruits. N. leucoloma is native to eastern South America. During the first half of the 20th century, it spreads to Australia, New Zealand, South Africa and the USA. In 2005, it was reported in the Azores where it occurs in the wild. In suitable conditions, N. leucoloma can develop from egg to adult in about 12 months with adults emerging during spring and summer. Outside of South America only females are known, they develop and lay eggs without fertilisation. Eggs are usually laid in the soil but can be laid on the stem or lower leaves of hosts. Larval root feeding causes damage to root surfaces leading to stunting and yield or quality losses. Larvae can tunnel inside potato tubers causing significant losses. Pupation takes place in the soil in spring and summer. Larvae and eggs that are laid late in the summer overwinter. Plants for planting and plant products, such as potatoes, provide potential pathways for entry into the EU. The suitable climate and the wide availability of host plants provide conditions to support the establishment of N. leucoloma in the EU. N. leucoloma is regulated in the EU by Commission Implementing Regulation 2019/2072 (Annex IIA). The import of soil or growing medium, from third countries other than Switzerland, is prohibited in the EU and therefore so far inhibited the entry of N. leucoloma larvae and pupae. All criteria assessed by EFSA for consideration either as a potential union quarantine pest or as a potential regulated non-quarantine pest are met.