The Cypress aphids in the South of France

In the South of France, Cinara (Cupressobium) cupressi, the main Cypress aphid, has been studied during 6 years on a mixed hedgerow in which Cupressus sempervirens and C. arizonica had been planted alternatively. In the area, this monoecious aphid is anholcyclic and heavily attended by ants. Continuous observation of the trees and of the colonies allowed a description of the population dynamics and the characterization of the damages. The two cypress species are regularly attacked, but the aphid appears earlier, remains longer and is more abundant on C. sempervirens, than on C. arizonica. The distribution of the colonies among trees is contagious. Some trees or groups of trees are attacked more frequently and/or present colonies earlier, suggesting that the tight interaction with ants may induce hivernation and early attack in some places.