Bark beetle and woodborer insects’ outbreak as a potent driver of Atlas cedar (Cedrus atlantica (Endl.) Carriere) forests dieback in Aures -East Algeria-

Abstract In order to shed light on the insect part involved in the forest decline associated with Atlas cedar (Cedrus atlantica (Endl.) Carriere.), an etiological study was carried out on eight representative stations in the Aures mountains located in Eastern Algeria. 1,728 woodlogs was prospected, representing three levels of tree’s health status (healthy, decaying, and moribund) and four heights (base, medium, crown, and branches) over three years (2010, 2013 and 2016). From this large-scale investigation, it was found that beetles caused the most important damages on Atlas cedar trees, 22 species of which belong mainly to the Scolytidae (Cryphalus numidicus, Scolytus numidicus, Crypturgus cedri, Phloeosinus cedri, and Hylastes batnensis); the Buprestidae (Melanophila marmottani and Anthaxia martini) as well as the xylomycophage Ciidae (Cis corioli) were found to be the most significant decline agents who impacted most of the phytosanitary status of Cedrus atlantica. The thorough examination of the infestation level and the manner of how these insects affected each stage of decline (taking into account the various specimens collected at different high levels) showed an intra and inter-specific heterogeneity, as well as a succession of the xylophagous entomofauna when comparing various stations.