o:8488 Phenological Study of the Spruce Bark Beetles Ips typographus (L.) and Pityogenes chalcographus (L.) (Coleoptera: Curculionidae) on Tara Mountain, Serbia en Abstract This study presents a detailed phenological analysis of two important spruce bark beetle species, Ips typographus (L.) and Pityogenes chalcographus (L.) (Coleoptera: Curculionidae), in the region of Tara Mountain in western Serbia, conducted over a period of three years (2016–2018). Field observations were complemented by growth degree days (GDD) calculations to determine thermal thresholds for development under local climatic conditions. Both species were found to be univoltine, with the potential for a sister generation. Timing of life stages, particularly adult emergence, was closely linked to accumulated thermal units, with developmental thresholds of 557 GDD reached between early and mid-July each year. The results highlight the influence of microclimate and temperature variability on bark beetle development and illustrate the potential for phenological shifts under future climate scenarios. These findings provide a regional framework for predicting outbreaks and improving forest pest control strategies in the face of ongoing climate change. voltinism; European spruce bark beetles; growing degree days (GDD); climate change; western Serbia 1552099 10.15177/seefor.25-16 1552102 https://www.seefor.eu/vol-16-no-2-milosavljevic-et-al-phenological-study-of-the-spruce-bark-beetles-ips-typographus.html 2025-11-20T13:52:33.872Z 44 yes 46 Marija Milosavljević 0000-0002-0208-5402 Mara Tabaković-Tošić person Snežana Stajić person 0000-0001-9023-3542 Goran Češljar person Suzana Mitrović person 0000-0003-1855-4418 application/pdf 3395378 https://unilib.phaidrabg.rs/o:8488 no yes 16 70 1552253 South-East European Forestry SEEFOR 16 2 2025