Baltosidis, 2021

Szawaryn, Karol, 2021, The first fossil Microweiseini (Coleoptera: Coccinellidae) from the Eocene of Europe and its significance for the reconstruction of the evolution of ladybird beetles, Zoological Journal of the Linnean Society 193, pp. 1294-1309 : 1303-1304

BALTOSIDIS SZADZIEWSKII SP. NOV.

( FIG. 4A–E )

Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 0DE65C57-3418-455A-A64C-79C12CBBBD89

Material examined: Holotype. GPIH no. 5032, Carsten Gröhn collection no. C4673, FT-IR 9613 ( Fig. 5 ), sex unknown, no syn-inclusions. Paratype. CCHH 891, specimen preserved in epoxy resin, sex unknown, no syn-inclusions.

Diagnosis: Baltosidis szadziewskii is characterized by fine, short setae on pronotum and elytra, abdominal postcoxal lines fused with accessory lines apically forming v-shape. Ventral surface setose.

Description: Total length = 1.13 mm, total width = 0.78 mm. Body elongate oval ( Fig. 4A, B ). Head, pronotum and elytra shortly setose. Pronotum covered with small, irregular punctures ( Fig. 4E ), punctures associated with setae ( Fig. 4D ), setae on pronotum longer than those on elytra. Metaventrite covered with moderately large punctures separated by distance of about its double diameter, punctures associated with short setae, without distinct additional rows of large punctures anteriorly to hind coxae, metaventral postcoxal lines complete laterally, straight, discrimen visible in posterior half. Elytra covered with dense punctures of similar size as those on pronotum, irregularly distributed, punctures associated with short setae, sutural line present in apical half, elytral margin narrow ( Fig. 4A ). Elytral epipleuron punctate, punctures associated with short seta, incomplete, reaching to posterior border of ventrite 3. Wings well developed ( Fig. 4A, B ). Ventrite 1 distinctly shorter than 2 and 3 combined, surface covered with punctures of same size as on metaventrite but distributed more sparsely, abdominal postcoxal lines reaching oneseventh of length of ventrite 1 at level of hind coxa, incomplete, accessory line distinctly curved and roundly merged to postcoxal line, forming narrow v-shape pattern ( Fig. 4C ). Ventrite 2 longer than ventrite 3, ventrites 3 and 4 subequal in length, ventrite 5 large, rounded, slightly shorter than ventrite 2. Ventrites 2–5 covered with moderately long setae. Femora swollen, tibiae extended apically, tarsi tetramerous.

Etymology: The specific epithet is dedicated to Prof. Ryszard Szadziewski (University of Gdańsk, Poland), entomologist and expert on recent and fossil Ceratopogonidae (Diptera) , who encouraged me to investigate Baltic amber coleopterans.

Locality and horizon: Eocene, Baltic amber, Gulf of Gdańsk area (secondary deposit).

Note: I examined one additional specimen from the Bitterfeld deposit (CCHH 743-1), which also belongs to the genus Baltosidis . However, its state of preservation (large bubble on ventral side) prevents correct identification to the species level.

Figures

Figure 4. Baltosidis szadziewskii. A, habitus dorsal. B, habitus, ventral. C, postcoxal lines on ventrite 1. D, setation on pronotum. E, pronotum. Holotype, GPIH (5032A–E).

Figure 5. FT-IR absorbance spectra of analysed amber pieces with the indication of museum inventory numbers above each spectrum.