External anatomy and life cycle of Aphis nasturtii (Hemiptera: Aphididae)

Abstract

Aphis nasturtii (Kaltenbach) is a cosmopolitan species who can cause direct damage to the plants by extracting the sap, and indirectly it is a vector to 16 plant viruses. The study presents data referring to the external morphological characteristics, to the biometrical measurements and to the life cycle of Aphis nasturtii. The researches have been carried out for a period of four years on the potato and for a period of two years on the orchards from Romania. At the Aphis nasturtii species the smallest length of the body found for aphids captured in Romania was 1.10 mm, while the biggest was 2.40 mm. In the conditions of the Western part of Romania Aphis nasturtii winter egg stage started in October. On the primary host the aphids gave birth parthenogenetically to three generations of fundatrigenous. In July, the winged form migrated to the secondary host, where successive generations have been born through parthenogenetic reproduction. Gynopara in October return to the primary host and give birth to wingless oviparae that mate with males and lay winter eggs. The biometrical measurements of Aphis nasturtii help to complete knowledge on external morphology of this species. By knowledge of biology and ecology of Aphis nasturtii a protocol for the prevention and control can be established.