Mylabris quadripunctata

Mylabris quadripunctata (Linnaeus, 1767) (Plate II, 11, 12; Fig. 2 C) Material examined: Bulgaria, Sakar Mts, W of Ustrem Vill., 42°01.434’N 26°26.828’E, 107 m a.s.l., meadows (Fig. 2 D), 22.vii.2021, 1 ♂ (BFUS- MEL000056), 1 ♀ (BFUS- MEL000057), on Cichorium intybus L., D. Gradinarov leg.; the same data, 23.vi.2023, 17 ♂♂ (BFUS-MEL000058, BFUS-MEL000059, BFUS-MEL000060, BFUS-MEL000061, BFUS-MEL000062, BFUS-MEL000063, BFUS-MEL000064, BFUS-MEL000065, BFUS-MEL000066, BFUS-MEL000067, BFUS-MEL000068, BFUS-MEL000069, BFUS-MEL000070, BFUS-MEL000071, BFUS-MEL000072, BFUS-MEL000073, BFUS-MEL000074), 4 ♀♀ (BFUS- MEL000075, BFUS-MEL000076, BFUS-MEL000077, BFUS-MEL000078); Bulgaria, Sakar Mts, N of Sakartsi Vill., 42°03.696’N 26°17.567’E, 365 m a.l.s., dirt road, meadows, 23.vii.2023, 3 ♂♂ (BFUS- MEL000079, BFUS-MEL000080, BFUS-MEL000081), 4 ♀♀ (BFUS- MEL000082, BFUS-MEL000083, BFUS-MEL000084, BFUS-MEL000085), on Cichorium intybus L. and Apiaceae, Y. Petrova leg. Notes: All examined specimens from both localities (near Ustrem and near Sakartsi villages) have an unusual elytral black pattern in which the spots in the basal third of the elytra and the middle spots are almost or completely fused into two fasciae (Plate II, 11, 12). This pattern resembles that of M. variabilis, with which such individuals can be accidentally confused. In our study, the two species occur sympatrically (see below for the distributional data of M. variabilis), and in such mixed populations, the most reliable distinguishing feature is the morphology of the male genitalia (Plate II, 11a, 11b, 13a, 13b; Pan & Bologna 2014). The observed similarity in elytral black pattern of M. quadripunctata and M. variabilis may represent an example of classical Müllerian mimicry, where two different defended species share the same warning signal (Speed 1999).