In 1998 the presence of the horse chestnut leaf-miner, Cameraria ohridella Deschka-Dimic was reported in Cluj- Napoca. During 2000 – 2003 research concerning the extent, biology, ecology at this micro-lepidopteron, a new pest in our country, was performed. Signaled for the fi rst time in Western area of our country (1998), then in Central (1998), Southern (1999), and Eastern (2003) part of the country, the spread year by year conquering new territories. In the clime conditions of our country, the insect had 4 generations in 2000, and 3 during 2001 – 2003, remaining in hiemal diapauses during pupae stage, inside of the silk cocoons from the galleries of larvae feeding. The fl ight of the butterfl ies from the IIIrd generation (hiemal) is recorded in the beginning of May. The Ist generation has a developmental stage during 15 May – 30 June, the IInd during 1 July – 15 August, and the IIIrd during 15 August – 15 May.
