Abstract <p>The shift towards “close-to-nature forestry” in Central Europe led to an area-wide decrease of open forest structures and a decline of many photophilous species or taxa. One of them, the endemic taxon <i>Zygaena angelicae elegans</i>, only occurs on the western margin of the Swabian Alb, Germany. Five of only 37 (mostly small) populations became extinct since 2000; hence, this evolutionary significant unit is at the verge of extinction. We assessed landscape-scale drivers of population persistence by comparing contemporary surveys with data from the 1990s and analysed larval microhabitat selection to provide target values for habitat management, which we tested in a case example. While population size was highest in open, south-exposed slopes, population persistence strongly decreased with increasing distance to the next occupied patch, with high extinction risk above 1.3–1.5&#xa0;km. Occurrence and abundance of larvae was mostly driven by afternoon insolation (&gt; 135&#xa0;min) and the availability and height of the larval host plant <i>Coronilla coronata</i> (&gt; 15 and &gt; 25&#xa0;cm for occurrence and abundance, respectively), which in turn depended on low canopy (&lt; 61%) and shrub cover (&lt; 26%).</p> Implications for insect conservation <p>Habitat management reducing forest encroachment based on these thresholds resulted in an immediate boost of local population size. Management plans targeting a stable metapopulation must focus on the expansion of current relict habitats and creation of new habitats in close vicinity (1.5 km) to existing populations, with rapid population responses indicating that a consequent implementation may save the highly endangered taxon from extinction.</p>