Holotype: ♂, Bulgaria SW, Struma River valley, Rupite, 41.462°N; 23.256°E, 30.iv.2013. J. Junnilainen leg & coll.: GPJJ201578 and red label “HOLOTYPE of Spiniphallellus chrysotosella Junnilainen“. – Paratypes: 1 ♂, same locality and data as holotype with green label DNA sample 24244 Lepid Phyl.; 3 ♂, Georgia Gremi 42.002°N; 45.657°E, 23–25.v.2011 J. Junnilainen leg., Coll. J. Junnilainen. 1 ♂, Turkey, Anatolia, Manavgat, 36.788°N; 31.416°E, 01.v.1996 K. Nupponen & J. Junnilainen leg., Coll. J. Junnilainen. Gen Prep No.7126 Bo Wikström. All paratypes with red label “PARATYPE of Spiniphallellus chrysotosella Junnilainen“.

Adult (Fig. 1). Wingspan 9–9.5 mm. Labial palp brown with golden shine. Antenna brown, slightly serrate. Head, tegula, and thorax dark brown with glossy golden and purple hue.

Forewing brown with golden shine, with five shiny golden spots: three on the costa, one at 1/5 length of wing from base extending to fold, second at middle of costa, and third 2/3 from base; two spots in fold: one at 1/3 wing length from base and second at 3/5 from base. Hindwing fuscous. Abdomen and legs brown somewhat shiny golden.

Male genitalia (Figs 2, 3). Sternite VIII broad sub-rectangular, laterally rounded, with broad anterior projections on both sides, posterior margin broadly rounded with weak medial indentation. Tegumen relatively short with V-shaped anterior margin; uncus formed as almost sub-rectangular plate, except with posterior margin broadly extended medially, latero-medially with two strong setae and with 6–8 short and thinner setae; valva twice as long as tegumen, elongate, apical half strongly hirsute, apex sharp, weakly pointed inwards; transtilla lobe relatively long, digitate, apically with some fine setae; posterior margin of vinculum medially with broad rounded indentation, laterally formed as sub-triangular plate, distally covered with fine setae; saccus broad, rounded; basal half of phallus almost round, distal part relatively slender, tapered apically; ankylosed by strongly sclerotized and tightly attached anellus.

Externally the new species is characterized by its forewing with gold shiny markings, which are absent in other close relatives. The species differs from S. fuscescens Bidzilya & Karsholt, 2008 by its longer and slenderer valva, longer transtilla lobe and by the form of its vinculum; from S. stonisi it differs by its broader uncus, slenderer valva and by distinctive transtilla lobes, lacking in S. stonisi; and from S. desertus it differs by its slenderer valva, narrower shape of the transtilla, and more rounded saccus.

Female genitalia. Unknown.

Bulgaria, Georgia, and Turkey.

Early stages are still unknown although Jasminum fruticans seems to be the most probable host plant. The imago is mostly day active. Flight period begins at the end of April or beginning of May. S. chrysotosella has probably been overlooked due to its small size and because it is apparently diurnal and might not be usually attracted to lights.

The species name is derived from its golden shiny forewing markings, which are absent from other related taxa.

Spiniphallellus was originally named based on the characteristic thorn or spine laterally in the medial part of the phallus. This process, however, is actually a strongly sclerotized part of the anellus, tightly fused to the phallus. The phallus is very difficult to remove during dissection without breaking the juxta-anellus complex.

The DNA barcode (sample ID MM24244) shows a very clear difference to all other moths in BOLD (www.barcodinglife.org). The nearest species is Diasemia grammalis Doubleday, 1848, which is an exotic Crambiinae moth differing by 8.16%. This barcode difference is so large that its placement is not considered meaningful. No other species of Spiniphallellus has been barcoded so far.