Identification of Diatraea spp. (Lepidoptera: Crambidae) based on cytochrome oxidase II

Abstract

Diatraea spp. (Lepidoptera: Crambidae) are a group of insects that are agriculture pests in many economically relevant crops such as sugarcane, sorghum, corn and rice. Recognized species for this genus respond differentially to natural enemies used in their biological control, emphasizing the importance of species in a regional approach. Currently, identification is based on the male genitalia. However, the availability of specimens collected from field and subjectivity based on the character recognition can seriously hamper species identification, and therefore result in inadequate pest management. To overcome this, individuals of Diatraea spp. preliminarily classified male genitalia and obtained from reared conditions and the field (both derived from natural populations occurring in Colombia) were analyzed using genitalic morphometry and molecular biology specifically using a fragment of the cytochrome oxidase subunit II (CO II) mitochondrial gene. Although morphometric analysis did not show any overriding results regarding genitalia morphology, the bioinformatics analyses of CO II sequences resulted in an adequate classification of the individuals within the recognized species. It also, revealed that the occurrence of clades associated with geographical distribution may be associated with cryptic species. The latter was also confirmed by a Single-Strand Conformation Polymorphism (SSCP) methodology evaluating the same fragment of CO II. This experimental approach allows properly recognizing each species and in consequence is proposed as an effective tool in Diatraea species identification.

Resistencia varietal al ataque por Diatraea spp. (Lepidoptera: Crambidae) en caña de azúcar

“…Los barrenadores de la caña de azúcar, Diatraea spp., son considerados las plagas de mayor importancia en este cultivo en América (Solis y Metz 2016) y en Colombia, particularmente en el valle del río Cauca, se ha venido presentando un incremento en los daños atribuibles a la predominancia de D. busckella Dyar & Heinrich, 1927y D. tabernella Dyar, 1911. Al parecer estas especies, recientemente registradas en la zona (Vargas et al 2013;Vargas et al 2017 y Barrera et al 2017) no solo han desplazado a D. saccharalis (Fabricius 1794) y a D. indigenella Dyar & Heinrich, 1927, especies tradicionalmente conocidas en la región (Ramírez et al 2015) sino que también el control biológico utilizado regularmente mediante las moscas taquínidas; Lydella minense (Townsend 1927), Billaea claripalpis (van der Wulp 1896), Genea jaynesi (Aldrich, 1932) Resumen: Los barrenadores del tallo, Diatraea spp., constituyen las plagas más importantes de la caña de azúcar en Colombia. En el país, el proceso de obtención de variedades no involucra la selección con respecto a la resistencia a insectos plaga, pero en la etapa final de selección se evalúa el porcentaje de entrenudos barrenados (intensidad de infestación) y se asigna una calificación de daño relativa al daño promedio obtenido en cada prueba, que luego de al menos tres pruebas da lugar a un promedio de calificación de daño denominado índice de resistencia (I.R.).…”

Resistance to Diatraea (Lepidoptera: Crambidae) stem borers in sugarcane is independent of species

“…The expression of pest injury may be affected not only by the different sugarcane stem borer species present, but also by variability within them. Variability has been found at the molecular level in populations of Eldana saccharina Walker (Lepidoptera: Pyralidae), D. saccharalis, D. lineolata , and D. centrella (Lange et al 2004, Palacio-Cortés et al 2010, Joyce et al 2016, Barrera et al 2017, Francischini et al 2019). However, even though host-plant resistant biotypes have not been reported within sugarcane stem borer species, there is a dearth of information available as to variation within many of the Diatraea species and their interactions with host plants.…”

Morphological and Molecular Identification of Diatraea grandiosella Dyar1 and Its Natural Enemies Associated with Maize Cultivation at Guanajuato, Mexico

“…Identification of Diatraea species has been based mainly on dissection of adult male genitalia (Barrera et al 2017). Species of the genus cannot be identified using only external traits because it includes very similar species (Solís and Metz 2016).…”