Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae): potential for entry, establishment and spread in Bulgaria

V. Ventsislavov, V. Krumov, O. Karadjova, E. Petrova, Z. Ilieva

Abstract: The tomato leaf miner Tuta absoluta, a devastating pest of tomato in South America, was reported from Spain in 2006 and has subsequently spread throughout many European countries, causing serious damages to tomato in the invaded areas. The pest can also develop on other cultivated plants, among which are peppers, eggplants and potatoes, posing a significant threat to agriculture. The present paper describes the major pathways for entry of the pest on the territory of Bulgaria and its potential for establishment and spread in the context of the Balkan region. It analyses the endangered areas in the country with emphasis on tomato cultivation, which is most at risk, and reviews the current national situation with examples of recent outbreaks. The steady decrease in tomato production in Bulgaria has led to an increase in import of tomatoes in order to meet the consumer demands. This contributes to a higher risk of entry of T. absoluta, as 65% to 99% of the imported fresh tomatoes come from countries where outbreaks of the pest have been observed during the past 5 years. Packing materials for import of tomatoes, peppers and eggplants, as well as imported planting material also present a risk and are considered in detail. T. absoluta has repeatedly entered Bulgaria through import from Turkey and Greece and it is very likely that it will continue to threaten the national vegetable production. The analysis of the available data through climatic modeling shows that the pest cannot permanently establish in the country outdoors, as it cannot survive the cold winter conditions. However, the establishment of transient field populations, developing 2 - 5 generations per year during the growing season, and permanent populations in greenhouses is a likely scenario. These facilitate the spread of T. absoluta to adjacent areas through flight and to distant locations through human-assisted means.

Keywords: Bulgaria; distribution; entry; establishment; Tuta absoluta

Date published: 2019-02-27