Molecular identification by PCR of the armyworm in southern Ecuador

Sumario: Spodoptera frugiperda is an insect pest of corn. This polyphagous species is included within the group of the armyworms, considered pests of economic importance in several countries of America. In corn, these larvae cause damage from the seedling to pre-ripeness stages. Identification of Lepidoptera is usually based on the morphology of adults, meaning that larvae must reach adulthood for their identification. Nevertheless, the larval period is the stage that causes mayor damage in corn. Currently, the use of molecular tools such as PCR, based on mitochondrial or nuclear DNA sequences, has been used for unambiguous identification of pests or biotypes from larvae. The objective of this study was to identify the presence of S. frugiperda species in white corn crops in the South of Ecuador at molecular level. For this, we used a PCR analysis with specific primers for S. frugiperda at the level of the mitochondrial gene of subunit 1 cytochrome oxidase (COI) I. A total of 360 larvae were collected in 36 sites distributed in three provinces: 18 in Azuay, 12 in Cañar and 6 in Loja, between January and March 2015. As a result, amplifications of molecular weights of approximately 500 pb corresponding to S. frugiperda were generated. This molecular characterization is, to our knowledge, the first one performed for the Austro of Ecuador.