Fluctuations of aphid populations on grapefruit (Citrus x paradisi Macfad.)

Abstract

Very few studies were carried out to investigate the aphids attacking grapefruit. These pests cause considerable damages on citrus trees and other crops. This paper reports on the fluctuations of aphids on grapefruit in the region of Skikda (Algeria). From January 2012 to December 2013, monthly surveys were performed to measure the abundance of aphids recorded on 16 leaves of grapefruit. Through this study, five aphid species were identified, among them Aphis spiraecola Patch, 1914 was the most numerous. Besides, we noticed that the populations of aphids reached high levels many times within the year. However, the most important densities were recorded in spring and autumn.

Keywords

• Aphis spiraecola
• Aphis gossypii
• inter-annual variations of populations
• intra-annual variations
• population dynamics