author(s)
Salim Lebbal, Malik Laamari

abstract
Aphids are important pests of many cultures in different regions worldwide. In this study, aphids and their seasonal dynamics were compared between three citrus species (orange, lemon and clementine) from an orchard composed of different citrus species, situated in Skikda (Northeast of Algeria). We sampled monthly, from January 2012 to December 2013, shoots or leaves from each species. Then we counted the number of aphids, aphid mummies and predators. We identified, during the investigation, four aphid species in total. The most abundant species observed was Aphis spiraecola. Moreover, the lemon trees were relatively the less infested species by aphids. On the other hand, this study showed the variability of the infestation degree by aphids between years. Nevertheless, we noted the highest levels of aphids in either spring or autumn. Thus, the monitoring of aphids should be carried out through the year in order to control these pests efficiently.