Variation in hindwing size and shape of Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae)

Abstract

Plutella xylostella (Linnaeus, 1758) has been claimed to be the most widely distributed Lepidoptera species. However, it is a highly polymorphic species, and there is evidence that what is known as P. xylostella is a species group, so it is possible that all records do not correspond to this species. Aim of the work was to evaluate the variability of hindwing size and shape of Venezuelan P. xylostella specimens and explore possible differentiation between groups of individuals. For this purpose, 126 specimens belonging to the entomological collections of the Museo del Instituto de Zoología Agrícola Francisco Fernández Yépez (MIZA, Central University of Venezuela) and the Instituto Nacional de Investigaciones Agrícolas (INIA), were sampled. Variation patterns of wing size and shape were studied by means of landmark-based geometric morphometrics. The analysis revealed significant differences in wing shape between three groups separated by differences observed in the bifurcation of the M vein. These differences may be due to intra- or interspecific variation; there is not enough evidence to discern. In Venezuela, there are three morphotypes of P. xylostella, separated based on differences in shape and size of their hindwings. It is important to clarify the identity of these morphotypes by combining these results with further information such as molecular data and immature morphological taxonomy.