Pest survey card on tomato leaf curl New Delhi virus

Abstract

This pest survey card was prepared in the context of the EFSA mandate on plant pest surveillance (M-2017-0137) at the request of the European Commission. Its purpose is to guide the Member States in preparing data and information for tomato leaf curl New Delhi virus (ToLCNDV) surveys. These are required to design statistically sound and risk-based pest surveys, in line with current international standards. Tomato leaf curl New Delhi virus is a clearly defined taxonomic entity. Although the main potential pathway of entry and spread of this virus via plants for planting of host plants is subject to prohibitions and specific measures designed to prevent entry and movement, the widespread occurrence and polyphagous nature of its vector Bemisia tabaci constitutes a risk for introduction and further spread of ToLCNDV given its persistent transmission biology. The virus is currently present in parts of the EU, and surveys in Member States can have several objectives, e.g. substantiation of disease freedom for countries or pest-free areas, or disease monitoring. The major hosts of ToLCNDV belong to the Solanaceae and Cucurbitaceae families, and detection surveys should thus target cultivated species belonging to these families. ToLCNDV is expected to be able to become established in most or all areas of the EU where B. tabaci is able to become established-outdoors or under protected cultivation-and where Solanaceae and Cucurbitaceae crops are grown. Surveillance should target symptomatic host plants in a fully grown crop. Because of the severity of its symptoms, surveillance of ToLCNDV can rely on visual examination. However, because its symptoms are similar or identical to those of other begomoviruses, its identification requires the use of validated laboratory assays.

A distinct strain of tomato leaf curl New Delhi virus that causes mosaic disease in ash gourd and other cucurbitaceous crops

“…The whitefly-transmitted Tomato leaf curl New Delhi virus (ToLCNDV) is a limiting factor for cucurbit production in Asian and European countries ( Srivastava et al, 1995 ; Hussain et al, 2004 ; Maruthi et al, 2005 ; Chang et al, 2010 ; Sangeetha et al, 2018 ). It has become a significant threat to numerous crops across plant families including the Apocyanaceae, Acanthaceae, Asteraceae, Cucurbitaceae, Caricaceae, Euphorbiaceae, Fabaceae, Malvaceae, Papaveraceae, Phyllanthaceae, and Solanaceae worldwide ( Kumar et al, 2015 ; Moriones et al, 2017 ; Zaidi et al, 2017 ; Nagendran et al, 2017b ; Ashwathappa et al, 2020 ; Gemert et al, 2020 ; Chakraborty and Kumar, 2021 ; Krishnan et al, 2023 ). The infection of ToLCNDV on cucurbits exhibits characteristic symptoms including yellow mosaic, reduction of internodal length, severe curling, vein swelling, rough skin, reduced fruit setting, etc.…”