Pristiphora Abietina Christ., Defoliator in Resinous Forest Stands of Lunca Bradului Forestry Department

Abstract

Pristiphora abietina Christ. is one of the most dangerous pests of coniferous forest stands, especially at those that are located outside their natural vegetation area. During four years this species was monitored in Lunca Bradului Forestry Department and it has been found that there is a trend of reduced infested areas and the degree of infestation. Infested area decreased from 2.85% (in 2010) to 0.39% (in 2013) of the total area of the Forestry Department. As a result of soil surveys it was found that larval hibernating density ranged from: 1.3 to 25.2 larvae / m² (in 2010, from 1.2 to 6.5 larvae / m² (in 2011) , between 1.1 to 2.9 larvae / m² (in 2012), and between 1.1 to 2.2 larvae / m² (2013). This trend is determined both by the action of chemical control of larvae and due to the contribution of useful entomofauna. In this infested stands, we proceeded to multiplying the ant mounds. Entomofauna of predatory Carabidae collected in Barber traps is represented by 36 species. The dominant species are: Carabus ulrichii Germar. and Harpalus distinguendus Duft.