Cessator brodzinskyi Ferreira and Ivie, 2017

Ferreira, Vinicius S. & Ivie, Michael A., 2017, The First Fossil Species of the Extant GenusCessatorKazantsev (Coleoptera: Lycidae): A New Leptolycini from Dominican Amber, The Coleopterists Bulletin 71 (1), pp. 57-60 : 58

Cessator brodzinskyi Ferreira and Ivie , new species

( Figs. 1–5 )

Diagnosis. Male. Among known Dominican amber species, C. brodzinskyi is characterized by dehiscent elytra and the cylindrical, filiform, very weakly subserrate antenna. The Wu species has expanded elytra in the posterior half, while Electropteron avus Kazantsev, 2012 shares the dehiscent elytra of Cessator . Electropteron has distinctly flattened and widened antennomeres from IV to XI. The antennal condition in the Wu species is not clear in the photograph. Further, Cessator has antennomere II much shorter than III, while both II and III are subequally short in Electropteron and the Wu species. Cessator brodzinskyi can further be separated from E. avus and the Wu species by the short, transverse pronotum (3:6), which is less transverse in E. avus (4:6), while the Wu species is as long as wide. Color also differs in these species, with the base of the elytra completely black in C. brodzinskyi and in the Wu species, while it is yellowish in E. avus .

From other Cessator species , C. brodzinskyi differs from Cessator luquillonis Kazantsev, 2009 and C. parda in having the pronotum yellow, while it is black in the others. A wide variety of color patterns is seen in the undescribed extant material before us, so having the same color pattern should not be considered strong evidence of conspecificity. The antennae of the previously described species and most of the several undescribed species we have seen are short and stout with the last antennomere dark, and the gena (from the eye to the posterior margin of the head) is as long as or longer than the eye when viewed from below (see Kazantsev 2009, figs. 3, 32). Cessator brodzinskyi has long antennae, a white antennomere XI, and the gena behind the eye apparently shorter than the eye. There are specimens from Cuba and the Dominican Republic that have antennae and genae similar to C. brodzinskyi , but further discussion of these will be left for a revision of the genus by the first author.

Description. Male. With the general characteristics of the Leptolycini ( Miller 1991) . General coloration dark black-brown, except pronotum, legs, and antennomeres XI yellowish. Body elongate ( Fig. 1 ). Head transverse, small, not covered by pronotum, hypognathous. Eyes round, large, protuberant, coarsely granulate ( Figs. 1, 4 ). Maxil- lary palp 4-segmented, apical palpomere short, acute; mandibles not visible. Antennae inserted on gibbous prominence ( Figs. 1, 3 ); subserrate, subcylindrical, densely setose; attaining median portion of elytra; antennomere I subconical, antennomere II short, ca.0.25X length of I; III ca. 0.25X longer than I; antennomeres IV–X subequal to III; XI slightly longer. Pronotum transverse trapezoidal (3:6); margins thick, prominent; with obscure median impression in posterior third ( Fig. 3 ). Scutellum subquadrate, notched posteriorly ( Fig. 1 ). Prosternum short, V-shaped, posterior margin rounded ( Fig. 4 ); mesoventrite trapezoidal, posteriorly rounded. Metaventrite convex; posterior lateral angles acute; metadiscrimen complete, attaining posterion margin of mesoventrite ( Fig. 2 ).

Elytra elongate, ca. 7X longer than pronotum, reaching nearly to end of abdomen when abdomen fully extended, distally dehiscent, apparently with 3 elytral costae ( Fig. 1 ). Legs slender, elongate; trochanters tubular, ca. 0.33X length of femur; femora and tibiae clavate. Pro- and mesocoxae moderately oblique, elongate, projecting; metacoxa transverse. Abdomen with 8 ventrites (sternites II–IX), ventrite VII notched medially, IX elongate ( Fig. 2 ). Male genitalia with median lobe elongate, leptolycine-like. Length: 2.5 mm. Width (across humeri): 0.5 mm.

Female. Unknown, probably larviform.

Type Material. Holotype, male. Dominican Amber, Oligocene to Miocene (between 3 and 33 MYA) from Santiago mine (from West Indian Beetle Fauna Project collection, to be deposited in the US National Museum of Natural History ).

Etymology. The species was named after Jacob Brodzinsky in acknowledgement of the gift of the specimen to this study and his general assistance, hospitality, and friendship to MAI and many other visiting entomologists.

Discussion. The final division between Calopterini and Leptolycini remains unclear (Ferreira and Ivie 2016). Bocákova (2003, 2005) has done much to formalize the limits of the Calopterini , but points out that more study is needed. As is the case in several groups, C. brodzinskyi shares common features of both Leptolycini and Calopterini , including the absence of a transverse carina on the pronotum ( Calopterini ), reduced mouthparts (both Calopterini and Leptolycini ), and dehiscent elytra ( Calopterini and Leptolycini ). However, this species has the general appearance of a Leptolycini , including reduced mouthparts, the clearly dehiscent elytra, and the antennae inserted on a gibbous prominence ( Figs. 3, 4 ). A key character for distinguishing calopterines and leptolycines is the shape of the plantar pads of tarsomere 4, which are expanded laterally in Calopterini and narrowed in Leptolycini ( Miller 1991; Ferreira and Ivie 2016). Cessator brodzinskyi has tarsomere 4 narrow although we could not see the plantar pad itself. Extant congeners have the plantar pad clearly narrow, and this is used as a deciding factor for the taxonomic placement of this species in the Leptolycini .

Figures

Figs. 1–5. Cessator brodzinskyi, holotype. 1) Dorsal view; 2) Ventral view; 3) Pronotum and head; 4) Prosternum and mouthparts; 5) Antenna. Scale bar = 0.5 mm.