Scientific Opinion on the pest categorisation of Circulifer haematoceps and C. tenellus

Abstract

The Panel on Plant Health performed a pest categorisation of Circulifer tenellus (Ct) and C. haematoceps (Ch) (Hemiptera, Cicadellidae) for the European Union (EU) territory. They are well-defined insect species that can be identified on the basis of external morphology and male genitalia. Ch and Ct are considered to originate from the Old World; Ct is also present in North America and the Caribbean. In the EU, Ch is reported in 11 Member States, mostly in southern or central Europe, and Ct is reported in Spain, France, Italy and Greece. Neither species is harmful by itself, but they are vectors of Spiroplasma citri, the causal agent of, for example, citrus stubborn disease. The major impact of Ct in North America results from the transmission of Beet curly top virus to sugarbeet. Ct also transmits 'Candidatus Phytoplasma trifolii' and Ch transmits 'Ca P. asteris'. There is no transovarial transmission of the pathogens. Ch and Ct are regulated harmful organisms in the EU and listed in Annex II, Part A, Section II, of Council Directive 2000/29/EC together with Spiroplasma citri and with respect to plants of Citrus, Fortunella, Poncirus and their hybrids, other than fruit and seeds, despite the fact that Ct and Ch have a larger host range. Ch and Ct are likely to be disseminated by plants for planting (the eggs are laid into the leaf veins and petioles), they have also been observed to hitch-hike on terrestrial vehicles, and Ct is known for its very high flight capacity. Both species have many hosts, in particular in the Chenopodiaceae, Brassicaceae and Asteraceae. Ecological conditions in the risk assessment area are suitable for the establishment and spread of S. citri, at least where citrus is currently grown.

Pest categorisation of Beet curly top virus (non‐EU isolates)

“…Seasonal dispersals can occur over relatively long distances. In the USA reports have shown that C. tenellus can migrate from the desert in Utah were it breeds, to invade distant sugar beet crops that are up to 300 km away (EFSA PLH Panel, 2015). Similar migration patterns and distances have been described for C. tenellus in the southwestern part of the USA or from northern Mexico to Miami, Florida (Severin, 1933;Dorst and Davis, 1937).…”

“…Consequently, outside the natural range of the vector, BCTV infected plants may occur but without further spread of the virus from its source. As explained in the 'Scientific Opinion on pest categorisation of C. haematoceps and C. tenellus' (EFSA PLH Panel, 2015), it is possible that C. tenellus is already present (but not reported) in few EU countries, such as Portugal, Slovenia and Croatia, and if still absent from these countries, it could spread into presently uncolonised areas where ecoclimatic conditions are suitable for its development.…”