Mesocentrus palaeoeuropaea, Butcher & Zaldivar-Riverón & Kamp & Rolo & Baumbach & Quicke, 2014

Butcher, Buntika Areekul, Zaldivar-Riverón, Alejandro, Kamp, Thomas Van De, Rolo, Tomy Dos Santos, Baumbach, Tilo & Quicke, Donald L. J., 2014, Extension of historical range of Betylobraconinae (Hymenoptera: Braconidae) into Palaearctic Region based on a Baltic amber fossil, and description of a new species of Mesocentrus Szépligeti from Papua New Guinea, Zootaxa 3860 (5), pp. 449-463 : 453-454

Mesocentrus palaeoeuropaea sp. nov. †

( Figs 4–7 )

Holotype ♂. Braconidae /C. V. Henningsen [the collector]/ 22-6-1953 [the collecting date]. No further information is available.

Length of body 3.25 mm and of fore wing c. 3.3 mm.

Antenna with 19 flagellomeres, median flagellomeres nearly quadrate, scapus weakly flared apically. Fore wing vein (RS+M)a strongly sinuate ( Fig. 7 ). Width of head 1.6 x width of face. Face produced into a distinct point medio-dorsally between antennal sockets. Clypeus separated from face dorsally by a distinct groove. Hypoclypeal depression strongly convex medio-dorsally. Malar suture weak, curved. Occipital carina not weakened mediodorsally. Frons strongly depressed laterally. Mesosoma 2 x longer than maximally high. Fore wing vein (RS+M)a strongly sinuate ( Fig. 7 ). Fore wing vein 3RSa 1.5 x r-rs, 0.38 x 3RSb, vein (RS+M)a strongly sinuous. Hind wing vein 1M 1.1 x M+CU, m-cu antefurcal. Fore tibia with weak longitudinal dorsal ridge ( Fig. 5C ). Fore telotarsus approximately 0.8 x length of fore basitarsus. First metasomal tergite approximately as long as posteriorly wide with submedial carinae apparently more prominent than medial carina. 2 nd metasomal tergite longitudinally striate. 3 rd tergite apparently entirely smooth.

Notes. Differs from extant species of Mesocentrus in having a distinct (though weak) midlongitudinal ridge on the fore tibia, a groove separating the clypeus from the face medio-dorsally, and flared basal flagellomeres. Whilst it could be argued that it might equally be placed in an extinct genus rather than Mesocentrus , the differences are rather slight and only the lack of dorsal separation of the clypeus in Mesocentrus would support its monophyly relative to the extinct species. Despite careful visual examination we were unable to determine whether the eyes of the fossil specimen are setose as in the extant species, and such detail is below the resolution of the synchrotron imaging system employed, though it seems likely that they are at least less setose if not completely glabrous.

Etymology. Name refers to its ancient European provenance.

Figures

FIGURE 4. Mesocentrus palaeoeuropaea sp. nov. 3D surface rendering based on synchrotron X-ray microtomography data. A, B, approximately lateral views, showing raw surface with air bubbled over posterior of mesosoma, and with air bubbles removed, respectively; C, D, head, dorsal and lateral aspects respectively.

FIGURE 5. Mesocentrus palaeoeuropaea sp. nov. 3D surface rendering based on synchrotron X-ray microtomography data. A, mesosoma and most of 1st metasomal tergite, lateral view; B-D, fore, middle and hind legs respectively.

FIGURE 6. Mesocentrus palaeoeuropaea sp. nov. A, 3D surface rendering based on synchrotron X-ray microtomography data. A, head, front view; B, mesosoma and 1st metasomal tergite; C, ventral view of head and body; D, dorsal view of remains of propodeum and metasoma.

FIGURE 7. Mesocentrus palaeoeuropaea sp. nov. wings. 3D surface rendering based on synchrotron X-ray microtomography data showing wings.