Spatio-temporal evolution of Platypus cylindrus (Col., Platypodidae) attacksin a young cork oak stand after debarking:case study of the M’ Sila cork-oak forest (North Western Algeria)

Abstract: Two young plantations of the M’Sila cork oak forest (north-west Algeria) debarked insummer 2007 were selected to follow the rate and intensity of Platypus cylindrus infestation. Thecolonization of the 216 sample-trees was assessed monthly by counting the insect penetrationholes. After eight months of survey (December 2007-July 2008), the results showed an increasingrate of trees infestation, that varied from 26% in winter to 44% in July, with an average densityvarying during this period from 22 to 130 holes/m2. Insect population distribution insect on thetrees is not at random but corresponds to a strategy depending on the following treecharacteristics: size (height < 6m, circumference 2.5, debarking height > 1.5m); sanitary conditions (weak and declining trees).