24–25 Heads and pronota of 5th instar larvae, right lateral views. 24 Ecclisopteryx dalecarlica Kolenati, 1848 25 Drusus botosaneanui Kumanski, 1968 26 Drusus serbicus Marinkovic-Gospodnetic, 1971, 5th instar larva, head, right lateral view (dotted oval: spinule area). 27–29 Heads and pronota of 5th instar larvae, frontal views. 27 Drusus nigrescens Meyer-Duer, 1875 (arrows: long dark setae reaching dorsal midline; sro: serrated outline of pronotal ridge; numbers refer to setal positions) 28 Drusus mixtus (Pictet, 1834) (arrows: long dark setae not reaching dorsal midline; numbers refer to setal positions) 29 Drusus aprutiensis Moretti, 1981 (arrows: long dark setae not reaching dorsal midline; numbers refer to setal positions). Scale bars: 0.5 mm.