Population age structure of the green beach aphid, Myzus Persicae [Sulzer] [Homoptera: Aphididae] in Cumin fields in Assiut Upper Egypt

ABSTRACT

The present studies were carried out during 2011-2012 and 2012-2013 on cumin growing seasons. The main objective was to study population age structure of the green peach aphid, Myzus persicae [Sulzer] infesting cumin plants in Assiut, Upper Egypt. When using beginning of cumin planting as a starting date, data show that the migration of the green peach aphid from overwintering site into cumin fields occurred after about 50 days [nearly during the end of December]. The population then increased to become 10% of the maximum number after 66 days [nearly during the first half of January]. Maximum population density of the green peach aphid occurred after about 95 days. Therefore, the peak of abundance could be expected around the first half of February. After the population reached it's the highest level, it generally declined and reached 10% of the maximum after 121 days. The population then vanished from the cumin field in about 132 days [toward the middle of March]. The present results indicate that the number of green peach aphid was significantly higher in the second season 2013 [421.3 aphids / 10 plants], than that of the first season 2012 [249.30 aphids / 10 plants]. The differences in levels of infestation between the two seasons might be attributed to the differences in weather factors [temperature, relative humidity] and /or the effect of the common natural enemies in each season