Plaumannion fistulosum Talamas, 2015

Talamas, Elijah & Buffington, Matthew, 2015, Fossil Platygastroidea in the National Museum of Natural History, Smithsonian Institution, Journal of Hymenoptera Research 47, pp. 1-52 : 27-29

Plaumannion fistulosum Talamas sp. n.

Figures 79 , 80-82

Description.

Female body length: 1.40 mm (n=1). Sculpture of head: finely rugulose throughout. Occipital carina: complete. Cells along anterior margin of occipital carina: increasing in size ventrally.

Anterior margin of pronotum in dorsal view: transverse. Sculpture of dorsal pronotum: rugulose. Transverse pronotal carina anterior to epomial carina: present. Transverse pronotal carina posterior to epomial carina: present. Sculpture of lateral pronotum posterior to epomial carina: finely transversely striate. Pronotal cervical sulcus: indicated ventrally by line of large cells. Mesoscutal suprahumeral sulcus: comprised of deep cells across anterior margin of mesoscutum. Sculpture of mesoscutum: coarsely and deeply areolate rugose. Sculpture of mesoscutellum: coarsely and deeply areolate rugose. Lateral margin of axillar area: with line of cells in dorsal view. Size of cells along anterior margin of mesoscutellum: larger than cells of surrounding sculpture. Mesopleural carina: present as a strong ridge. Cells along dorsal margin of mesopleural carina: present. Sculpture of femoral depression: transversely rugose. Posterior mesepimeral sulcus: indicated by line of cells. Ventral mesopleuron: extending anteriorly between forecoxae.

Sculpture of anteroventral metapleuron: coarsely punctate-rugose. Sculpture of posterodorsal metapleuron: finely striate. Lateral portion of metanotal trough: comprised of large cells. Posterior propodeal projection: flat lamella that overlaps T1, fitting between sublateral keel and a short submedian carina.

Number of visible tergites: 6. Number of visible sternites: 6. Sublateral keels: present on T1-T4. Patch of fine setae on anterior part of lateral T1: present. Sculpture of T1-T4: coarsely areolate rugose. Sculpture of S1-S4: coarsely areolate rugose. Antecostal sulci of T2-T3: indicated by line of cells larger than surrounding sculpture. Sculpture of T6: finely punctate. Posterior margin of T6: emarginate. Patch of microsculpture on posteromedial S1: present. Cerci: visibly protruding from apex of metasoma.

Diagnosis.

Plaumannion fistulosum is closest to P. fritzi with which it shares a submedian carina on T1, coarse sculpture of the mesonotum and tergites, and a distinguishable mesoscutal suprahumeral sulcus. These two species can readily be separated by the sculpture of the head: finely rugulose in P. fistulosum and coarsely areolate in P. fritzi ; and by the sculpture in the dorsal part of the lateral pronotum: finely striate in P. fistulosum and smooth in P. fritzi . Plaumannion fistulosum is best separated from P. yepezi by the coarse and deep sculpture of the mesoscutum and mesoscutellum, the distinct mesoscutal suprahumeral sulcus, and the presence of submedian carinae on T1. Plaumannion fistulosum has 6 visible sternites, whereas P. yepezi and P. fritzi each have 5. We here expand the generic concept of Plaumannion to include species with 6 sternites.

Etymology.

The epithet fistulosum, meaning "full of holes" refers to the deeply areolate rugose sculpture found on this species.

Link to distribution map.

[http://hol.osu.edu/map-large.html?id=344197]

Material examined.

Holotype, female: DOMINICAN REPUBLIC: USNMENT00903996 (deposited in USNM).

Comments.

Plaumannion is an exceptionally rare genus, known from only a handful of specimens. Its presence in amber suggests the possibility that this genus was more common in the past, and perhaps its biology, although unknown, predisposes it to preservation in tree resin.

Figures

Figure 79. Plaumannion fistulosum, holotype female (USNMENT 00903996), head, mesosoma, metasoma, ventral view. Scale bar in millimeters.

Figure 80 - 82. Plaumannion fistulosum, holotype female (USNMENT 00903996) 80 head, mesosoma, metasoma, dorsolateral view 81 head and mesosoma, ventrolateral view 82 head and mesosoma, lateral view. Scale bars in millimeters.