Lately, 2 species of lepidopteran insects, Ostrinia nubilalis and Helicoverpa armigera, are very common in corn crops in the west of the country. They have the status of a pest in the larval stage and are a big problem for the phases after the formation of the cob when the attack itself is manifested. Recent studies as well as the opinions of farmers speak of an increase in the size of the adult populations and implicitly of the reproductive capacity and the number of harmful larvae in the crops. The present work comes with recognition information and comparison between the 2 species, both at the adult and larval levels, but also at other important stages in identification (pupa and egg). Among others already known, the identification of adults is easier because those of Helicoverpa are larger, with a more pronounced coloration than those of Ostrinia which are thinner in body, small in wingspan and lighter in color, more uniform. Our studies of corn crops in Palota locality (Bihor County) showed that the larvae are also differentiated by size and coloration in the same trend as the adult. The damage phenophases are somewhat staggered but concentrated especially during the cob formation period. While Ostrinia is specific to corn, Helicoverpa can attack various plants. The analysis of the size of the populations from the last 2 years highlighted a preponderance of the Helicoverpa species at the expense of Ostrinia. These differences are useful in identifying the species more quickly and taking appropriate measures for effective control.

corn, Ostrinia, Helicoverpa, identification, populationsize

agronomy

Presentation: poster