Research regarding the evolution of Autographa gamma L. species in center of Moldavia conditions

Abstract

Autographa gamma L. species is a polyphagous pest that attacks most crop plants, but prefer beets, soya, beans, potato, flax, hemp, and from legumes crops: cabbage, tomatoes, cucumbers, cauliflower. The attack occurs in hearths, where at larvae density above ETP (economical threshold pest) of 3 - 5 larvae/sqm is necessary crop protection measures. Adult collection with a light trap, observations and measurements made during 1993 – 2012, showed that Autographa gamma L. species was present in the study area, each year, the number of specimens collected ranged from 7 specimens (2002) to 157 specimens (1993), the average collections for the 20 years of observations was of 47,75 exemplare. The emergence of the first adults was recorded in the second or third decade of Aprilie, the insect flight continued without interruption until the end of the first decade of October. During this time, two flight curves were identified, first made by the adults of the hibernating generation, which recorded a flight peak in the second or third decade of May. The second flight curve was made by the adults of the summer generation and reached the top flight in the first or second decade of August. The observations and measurements have shown that under the Central Moldova conditions, the insect presented two generations per year, the hibernation occurs in larvae stage in the deeper layers of soil.