History of a disastrous biological invasion: Tecia solanivora in Ecuador
The history of the introduction and spread of Tecia solanivora (Lepidoptera: Gelechiidae – EPPO A2 list) in Ecuador is presented by Barragán et al. (2004). In Ecuador, the presence of T. solanivora was officially declared in 1996 in the province of Carchi (north of the country), although observations made by farmers suggested that it may have been present since 1994. The authorities took phytosanitary measures (restrictions on potato movements from infested areas and control of potato imports) to try to prevent any further spread of the pest. Information and training courses were also provided to growers. At the end of 1997, climatic conditions changed (as an effect of El Niño) to cooler temperatures and abundant rains. This led to an apparent disappearance of T. solanivora in all infested areas. It was rapidly concluded that the pest was no longer present, and uncontrolled trade of potatoes continued. In 2000, a systematic survey done in all potato-growing areas and on the main markets revealed that the pest was still widespread. At the end of 2000, climatic conditions returned to higher temperatures and lower precipitations, which were more favourable to potato production and to the insect. Potato production increased but market prices dramatically fell, and large amounts of unsold potatoes were abandoned in the fields. These readily constituted good resources for the rapid development of T. solanivora populations. In 2001-2002, the situation was critical with drastic increases of infected seed potatoes and infected crops. An international workshop took place in Quito in 2002. It highlighted the need for international cooperation in south America, for continuing research on biology and ecology, and for developing IPM strategies to control T. solanivora.
Sources
Barragán, A.; Pollet, A.; Onore, G. (2004) La teigne du Guatemala en Equateur. Comprendre une invasion biologique réussie outre-Atlantique pour la prévenir en Europe.
Phytoma – La Défense des Végétaux, no. 569, 52-54.