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 : 1300

BALTOSIDIS DAMGAARDI SP. NOV.

( FIG. 2A–J )

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:96CACFFB-9847-4DED-8212-8818CDDD25A3

Material examined: Holotype. GPIH no. 5030, Carsten Gröhn collection no. C8111, FT-IR 9615 ( Fig. 5 ), sex unknown, no syn-inclusions. Paratypes. GPIH no. 5031, Carsten Gröhn collection no. C4527, FT-IR 9614 ( Fig. 5 ), female, no syn-inclusions; ALD Co80, FT-IR 9616 ( Fig. 5 ), sex unknown, no syn-inclusions.

Diagnosis: Baltosidis damgaardi can be distinguished from congeners by pronotum and elytra covered with two types of setae: long, stiff bristles intermixed with short hairs. Moreover, its abdominal postcoxal lines are widely separated from accessory lines. Ventral surface setose.

Description: Total length = 1.05–1.18 mm, total width = 0.73–0.79 mm. Body elongate oval ( Fig. 2A, B ). Head, pronotum and elytra covered with two types of setae: distinct long setae intermixed with fine, short hairs ( Fig. 2D ). Pronotum covered with medium-sized, irregular punctures about same size as those on elytra, punctures associated with setae ( Fig. 2B ). Metaventrite covered with moderately large punctures separated by distance of about its double diameter ( Fig. 2F ), punctures associated with short setae, additional rows of large punctures present anteriorly to hind coxae, metaventral postcoxal lines complete laterally, slightly descending, discrimen visible in posterior half. Elytra covered with dense punctures of similar size as those on pronotum, irregularly distributed, punctures associated with setae, sutural line present in apical third ( Fig. 2E ), elytral margin narrow. Elytral epipleuron punctate, glabrous, incomplete, reaching to posterior border of ventrite 3 ( Fig. 2A ). Wings not observed. Ventrite 1 as long as 2 and 3 combined, surface of ventrites covered with punctures of same size and density as those on metaventrite, abdominal postcoxal lines reaching one-seventh of length of ventrite 1 at level of hind coxa, incomplete, accessory line distinctly curved, short, broadly separated from postcoxal line, not forming v-shape pattern ( Fig. 2H ). Ventrite 2 longer than ventrite 3, ventrites 3 and 4 subequal in length, ventrite 5 large, rounded, about as long as ventrite 2. Ventrites 2–5 covered with long setae. Femora swollen, tibiae extended apically, tarsi tetramerous ( Fig. 2C ). A part of female genitalia can be observed in paratype C4527 (GPIH 5031) ( Fig. 2J ): coxites narrow, elongate, with two to three long setae attached to stylus.

Etymology: The specific epithet is dedicated to Anders L. Damgaard (Copenhagen, Denmark), collector of one of the paratypes, who allowed me to examine his collection of coccinellid beetles.

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

Figures

Figure 2. Baltosidis damgaardi. A, habitus ventral. B, habitus dorsal. C, details of tarsus. D, details of setation on elytra. E, tip of elytra with sutural lines. F, meso- and metaventrite. G, head, prosternum, mesoventrite. H, postcoxal lines on ventrite 1. I, details of an eye and antenna. J, tip of abdomen and female genitalia. Holotype, GPIH 5030 (A–D, F–I); paratype, ALD Co80 (E); paratype, GPIH 5031 (J).

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