In May 2001 a tornado passed through Vitosha and broke down about 20 000 m3 in the area of 62 ha mature Picea abies L. (Karst.) timber in the biosphere reserve Bistrishko branishte. The wind throws trees caused conditions for the development of one of the most dangerous insect pests in Picea abies L. (Karst.) forests - Ips typographus (L.) (Coleoptera: Scolytidae). In the middle of summer 2005 Picea abies drying ob Vitosha as a result of I. typographus attack covered about 200 ha.
Influence of the wind throw in biosphere reserve Bistrishko Branishte on the number of IPS typographus (L.) (Coleoptera: Scolytidae) and the condition of Picea Abies L. (Karst.) plantations on Vitosha