The species Diabrotica virgifera virgifera (Le Conte) is part of the Chrysomelide family of the Coleoptera order. Overall, the Diabrotica genus includes insects that prefer cucurbitaceae. In particular, beetles are adapted to differentiated feeding diet, so that Diabrotica virgifera feeds and survives predominantly in corn crops. In its living environment, the beetles are often seen on plants or flying, looking for food or in moments of copulation and feeding. However, at the level of morphology and taxonomy of adult form, the species of the Diabrotica genus are still confused, with a pronounced polymorphism. It is difficult to establish some genetic standards in identifying interspecific features. It is known that geographical locations can influence the ratio of individuals of a population, especially among individuals of the same species (males and females). Going on this point, in this paper we want to show whether there are or not morphological variations between adult insect populations, that have previously been collected from different places and different corn hybrids. Studies have been conducted on beetle populations from 7 different corn cultures. Crops were located in different locations (different localities from Timis and Arad County) in the western area of Romania. The collecting of the beetles was done manually, directly from plants (leaves and silk) in July and August, during of 2007 year. Detailed studies have been conducted at microscope. Later on, the beetles were divided into morphological categories. The targeted morphological characters were body length, antenna length, elytra coloration, and background color of the body. The observed results concluded that there are morphological differences between beetles from different populations but also between beetles belonging to the same population. Additionally, the variation of coloration has strengthened the fact that food color can imprint a similar nuance to the background color of the beetle and this is because feeding intensely on the same plants.

Diabrotica virgifera, polymorphism, insect populations, corn hybrids.

biology

Presentation: poster