ABSTRACT

The General Directorate of Plant Health (DGSV in Spanish) is recognized as the National Plant Protection Organization of the Federal Government of Mexico that acts under the Plant Health Federal Law. Some relevant plant protection programmes that Mexico is implementing include: The Huanglongbing (HLB) - Asian Citrus Psyllid (ACP) Programme, Mediterranean Fruit Fly Programme, National Fruit Fly Campaign, Pink Hibiscus Mealybug Programme and a permanent Phytosanitary Epidemiological Surveillance Programme to prevent the introduction and spread of regulated non-native pests. HLB or citrus greening is caused by the bacterium, Candidatus Liberibacter spp., and considered the most devastating citrus disease in the world. Once infected, it causes the death of orange, mandarin, grapefruit and lemon trees within 3 to 8 years. HLB is transmitted by the ACP, (Diaphorina citri Kuwayama), an insect vector widely distributed in most citrus producing regions of the world, including the citrus areas of Mexico. Until 2004, the disease only existed in Asia and Africa. It was first reported to occur in the Americas in 2004 (São Paulo, Brazil) and 2005 (Florida USA). In 2009, it was detected for the first time in Yucatán, Mexico. During that year, the national Mexican citrus production was 6.82 million tons (SIAP 2017). The economic impact evaluation by Salcedo-Baca et al. (2010) indicated that without the intervention of the Federal Government, HLB would be responsible for a reduction of the Mexican citrus production by 2.7 million tons in five years (39.6%). In spite of the spread of HLB, the citrus production in Mexico increased 11% to 7.56 million tons in 2015 (SIAP 2017). Today Mexico has 573 406 hectares (ha) of citrus compared to 545 947 in 2009, an increase of 5%. The first phytosanitary actions implemented on an area-wide basis were: (1) timely detection of HLB in agricultural and urban areas; (2) systematic elimination of infected trees in areas under surveillance; (3) control of the D. citri vector and (4) protection of propagative material in nurseries to avoid its infection. As a result of the successful HLB Programme implemented since 2008, adverse effects of the disease have largely been avoided. Management of HLB is organized through Regional Areas of Control (Areas Regionales de Control or ARCOs), which implement the following area-wide measures: epidemiological surveillance and monitoring of psyllids based on criteria associated to climate and host presence in urban 34and cultivated areas, and chemical and biological controls. From 2010 to 2015, 31 million parasitoid wasps Tamarixia radiata (Waterston) were produced and released in commercial citrus and backyard host areas of Yucatán, Quintana Roo, Campeche, Tabasco, Chiapas, Oaxaca, Hidalgo and Guerrero. The ARCOs are public-private organizations jointly operated by federal and state governments together with citrus grower associations. In 2016, the Mexican government allocated almost USD 8.5 million to the HLB Programme. With these actions, Mexico has largely mitigated the adverse effects of the disease while at the same time slightly increased citrus production. In addition, research programmes have been established together with scientific institutions to generate vegetative material with tolerance or resistance to the disease. Although the government has successfully implemented area-wide strategies for regional control, it is necessary to develop new and improved technologies to eliminate the vector, following the example of the Mediterranean fruit fly Programme in Mexico.