Xylophagous Entomofauna in Branches of Oaks (Quercus Spp.) and Its Significance for Oak Health in the Karst Region of Slovenia. Jurc, M., Bojović, S., Komjanc, B., & Kr ̌c, J. Biologia, 64(1):130–138, January, 2009.
doi  abstract   bibtex   
Samples of dying branches from 121 trees of Quercus pubescens, Q. cerris, and Q. petraea were taken from 102 sites in Seslerio autumnalis-Quercetum petraeae and Ostryo-Quercetum pubescentis forests. After nine months' rearing in eclectors, branches were cut to 20-cm sections, and signs of infestation as well as larvae and adult insects were noted. We analysed 395 sections of branches from Q. pubescens, 125 sections from Q. cerris, and 85 sections from Q. petraea. We found 44 adult insects: 45\,% were from the Cerambycidae family (Callimus angulatus ssp. angulatus, Poecilium alni, and Exocentrus adspersus), 18\,% were from the Scolytinae subfamily (Scolytus intricatus, Xyleborus dispar), 4\,% from the Buprestidae family (Coraebus florentinus), 4.5\,% from the Cleridae family (Tilloidea unifasciata), and 28.5\,% from other families. In addition, 145 larvae were found: 50\,% from the Cerambycidae family, 39\,% from the Buprestidae family, 4\,% from the Scolytinae subfamily, and 7\,% from other families. Significant difference in the abundance of adult insects and larvae with regard to the diameter of branch sections and the host species were found. 78\,% of dying branches showed signs of infestation. Species of the Buprestidae, Scolytinae, and Cerambycidae represent important factors in the decline in oak vitality in the lower Karst region of Slovenia. [Excerpt] Poecilium alni is a European species. It is polyphagous, mainly on oaks and other deciduous trees. Larvae develop under the bark of dead, mostly 1-2 cm thick branches. It is quite common throughout Slovenia, except in the high mountains, and its numbers and density are stable. It is a stenotopic species, inhabiting low altitudes and submountainous forests (Brelih et al. 2006). [] Exocentrus adspersus is a stenotopic, thermophilic, polyphagous species, occurring mostly on Quercus spp., but also on other deciduous trees, and in rare cases on conifers (Pinus spp.). Larvae feed under bark in the wood of dead, dry branches and shoots, particularly in the thin material in the crown of trees. Exocentrus adspersus used to be very rare in Slovenia, at least according to available data, however, in the past two decades it appeared in greater numbers and has become the most common species of the Exocentrus genus (Brelih et al. 2006). Because of its bionomics, E. adspersus represents a stress factor in the dying of oaks. In Germany, it is on the red list of threatened species (http://www.mu.sachsenanhalt. de/start/fachbereich04/artenschutz/files/299- 304 2004 rl sachs anh bockkaefer.pdf#search=%22 Exocentrus % 20adspersus%20%20%22). [] Scolytus intricatus is found on deciduous trees of the Quercus, Fagus, Ostrya, and Castanea genera (Pfeffer 1995). Sexually immature young beetles perform maturity eating on shoots or buds of growing vegetation as well as on the previous year's thinner branches of the host tree. Maturity eating, which usually takes place on a vital tree, causes dying of branches. Scolytus intricatus has a wide economic importance because it attacks freshly felled trees. It causes the dying of young small branches of healthy hosts, where the maturity eating of the beetles takes place. Females lay their eggs on trunks which are weakened by other factors, and they thus become another factor in the decline of the host trees, particularly oaks (F¨uhrer 1998). In Europe, S. intricatus is in the 35th place out of 40 harmful insect species (Grégoire & Evans 2004). This species is generally present in Slovenia, particularly in the Karst area of the Primorje region (unpublished data from Slovenian Museum of Natural History).
@article{jurcXylophagousEntomofaunaBranches2009,
  title = {Xylophagous Entomofauna in Branches of Oaks ({{Quercus}} Spp.) and Its Significance for Oak Health in the {{Karst}} Region of {{Slovenia}}},
  author = {Jurc, Maja and Bojovi{\'c}, Sr{\dj}an and Komjanc, Bo{\v s}tjan and Kr{\v c}, Janez},
  year = {2009},
  month = jan,
  volume = {64},
  pages = {130--138},
  issn = {1336-9563},
  doi = {10.2478/s11756-009-0024-8},
  abstract = {Samples of dying branches from 121 trees of Quercus pubescens, Q. cerris, and Q. petraea were taken from 102 sites in Seslerio autumnalis-Quercetum petraeae and Ostryo-Quercetum pubescentis forests. After nine months' rearing in eclectors, branches were cut to 20-cm sections, and signs of infestation as well as larvae and adult insects were noted. We analysed 395 sections of branches from Q. pubescens, 125 sections from Q. cerris, and 85 sections from Q. petraea. We found 44 adult insects: 45\,\% were from the Cerambycidae family (Callimus angulatus ssp. angulatus, Poecilium alni, and Exocentrus adspersus), 18\,\% were from the Scolytinae subfamily (Scolytus intricatus, Xyleborus dispar), 4\,\% from the Buprestidae family (Coraebus florentinus), 4.5\,\% from the Cleridae family (Tilloidea unifasciata), and 28.5\,\% from other families. In addition, 145 larvae were found: 50\,\% from the Cerambycidae family, 39\,\% from the Buprestidae family, 4\,\% from the Scolytinae subfamily, and 7\,\% from other families. Significant difference in the abundance of adult insects and larvae with regard to the diameter of branch sections and the host species were found. 78\,\% of dying branches showed signs of infestation. Species of the Buprestidae, Scolytinae, and Cerambycidae represent important factors in the decline in oak vitality in the lower Karst region of Slovenia.

[Excerpt] Poecilium alni is a European species. It is polyphagous, mainly on oaks and other deciduous trees. Larvae develop under the bark of dead, mostly 1-2 cm thick branches. It is quite common throughout Slovenia, except in the high mountains, and its numbers and density are stable. It is a stenotopic species, inhabiting low altitudes and submountainous forests (Brelih et al. 2006).

[] Exocentrus adspersus is a stenotopic, thermophilic, polyphagous species, occurring mostly on Quercus spp., but also on other deciduous trees, and in rare cases on conifers (Pinus spp.). Larvae feed under bark in the wood of dead, dry branches and shoots, particularly in the thin material in the crown of trees. Exocentrus adspersus used to be very rare in Slovenia, at least according to available data, however, in the past two decades it appeared in greater numbers and has become the most common species of the Exocentrus genus (Brelih et al. 2006). Because of its bionomics, E. adspersus represents a stress factor in the dying of oaks. In Germany, it is on the red list of threatened species (http://www.mu.sachsenanhalt. de/start/fachbereich04/artenschutz/files/299- 304 2004 rl sachs anh bockkaefer.pdf\#search=\%22 Exocentrus \% 20adspersus\%20\%20\%22).

[] Scolytus intricatus is found on deciduous trees of the Quercus, Fagus, Ostrya, and Castanea genera (Pfeffer 1995). Sexually immature young beetles perform maturity eating on shoots or buds of growing vegetation as well as on the previous year's thinner branches of the host tree. Maturity eating, which usually takes place on a vital tree, causes dying of branches. Scolytus intricatus has a wide economic importance because it attacks freshly felled trees. It causes the dying of young small branches of healthy hosts, where the maturity eating of the beetles takes place. Females lay their eggs on trunks which are weakened by other factors, and they thus become another factor in the decline of the host trees, particularly oaks (F\textasciidieresis uhrer 1998). In Europe, S. intricatus is in the 35th place out of 40 harmful insect species (Gr\'egoire \& Evans 2004). This species is generally present in Slovenia, particularly in the Karst area of the Primorje region (unpublished data from Slovenian Museum of Natural History).},
  journal = {Biologia},
  keywords = {*imported-from-citeulike-INRMM,~INRMM-MiD:c-4003848,forest-pests,forest-resources,ostrya-carpinifolia,scolytus-intricatus,slovenia},
  lccn = {INRMM-MiD:c-4003848},
  number = {1}
}

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