The studies were conducted on Cornus alba L. in the years 1999–2001 in the green areas on two sites: with heavy traffic (site A) and no traffic (site B). C. alba was the host plant for two species of aphids: Anoecia corni (F.) and Aphis salicariae Koch. A. corni was dominating in the years of observations and it was most numerous in 2000, while A. salicariae in 1999. The weather had a significant effect on the aphid population. After a mild winter and warm spring aphids were more numerous. High temperatures (over 30ºC) and stormy rainfalls as well as autumn ground frosts limited their population. On the other hand, aphidophagous species did not limit the population of aphids in any considerable manner. A. corni lowered the ornamental values of C. alba shrubs, especially in autumn.

95-110