A number of citrus trees in Malta have been infected with a deadly virus, a surveillance programme has found. 

The infected trees, originating from Sicily, were discovered in various garden centres following sampling and testing.

The monitoring was carried out by the Plant Health Directorate within the Parliamentary Secretariat for Agriculture with the objective of monitoring the status of pest occurrence.

The directorate activated the contingency plan and carried out the destruction of the infected consignments. To ensure the eradication of this pest, the public is being asked to notify the directorate of any purchase of citrus trees in the last six months.

The Citrus Tristeza Virus is the most destructive citrus disease worldwide

The Citrus Tristeza Virus is the most destructive citrus disease worldwide. Caused by a closterovirus, it is mainly transmitted by grafting of infected material and aphid vectors. The symptoms are not always visible and may remain unnoticed for a number of years without affecting fruit setting and production.

The most recent outbreak dates back to 2012 when an area in San Blas and Daħlet Qorrot Valleys in Gozo was demarcated. During the emergency action, citrus trees of various species were felled from the contingency area and the pest was completely eradicated. In 2013, the virus was detected again in trees brought from abroad in a local nursery.

Monitoring surveys for both the CTV and its vector have been conducted in different citrus orchards throughout Malta since 1999, with around 800 samples collected each year. In 2004, Malta was declared as a protected zone for this disease.

The virus cannot be controlled by any pesticide, and the only control mechanism for this disease is that of uprooting and burning infected trees and applying pesticides for the vectors.

The Plant Health Directorate can be contacted on 2292 6535 or freephone 8007 2310, or email at plant.health@gov.mt.