Nanoraphidia electroburmica Engel, 2002

Liu, Xingyue, Lu, Xiumei & Zhang, Weiwei, 2016, New genera and species of the minute snakeflies (Raphidioptera: Mesoraphidiidae: Nanoraphidiini) from the mid Cretaceous of Myanmar, Zootaxa 4103 (4), pp. 301-324 : 318-321

Nanoraphidia electroburmica Engel, 2002

( Figs. 12–13 )

Nanoraphidia electroburmica Engel, 2002: 3 .

Diagnosis. As for the genus.

Description. EMTG BA-001202. Female. Body length 3.9 mm (measured without ovipositor) and 5.9 mm (measured with ovipositor). Head length 0.4 mm; antenna length 1.0 mm; prothorax length 0.3 mm; meso- plus metathorax length 0.4 mm; forewing length 4.1 mm, maximum width 1.2 mm; hindwing length 3.9 mm, maximum width 1.1 mm; abdomen length 1.5 mm (measured without ovipositor) and 3.5 mm (measured with ovipositor); ovipositor 2.0 mm long and 0.05 mm wide. Morphology in general almost identical to holotype of N. electroburmica based on original description in Engel (2002). Cephalic and thoracic characters incongruent with that in Engel (2002) refer to: Mandible with only one subdistal inner tooth; pretarsus with arolium reduced. Abdomen with segments 1–2 narrow, but with remaining pregenital segments distinctly swollen. Detail morphology of genital segments hardly visible; sternum 7 about 1.5× length of tergum 8, with posterior margin not produced; segment 8 with a ventrally extending tergum 8, and probably membranous ventrally; tergum 9 rather narrow dorsad but broadened ventrad; ectoproct broadly ovoid; ovipositor distally narrowed and widely apart, with a pair of small digitiform gonostyli.

EMTG BA-002164. A male and a conspecific female preserved in same amber piece. Male. Body length 5.8 mm. Head length 0.9 mm; prothorax length 0.7 mm; meso- plus metathorax length 1.1 mm; forewing length 5.3 mm; hindwing length 4.8 mm; abdomen length 3.0 mm. Female. Body length ~ 8.2 mm (measured without ovipositor) and ~ 10.4 mm (measured with ovipositor). Forewing length 7.6 mm, maximum width 1.6 mm; hindwing length 6.3 mm, maximum width 1.5 mm. General morphology and wing venation almost same to that in holotype of N. electroburmica .

PCXJ BA-0004. A just emerged male with wings incompletely stretching on distal parts. Body length 3.8 mm. Head with clypeus and mouthparts not preserved; portion posterior to compound eyes nearly as long as eye diameter; ocelli invisible. Prothorax length 0.3 mm; meso- plus metathorax length 0.6 mm; forewing length ~ 2.9 mm; hindwing length ~ 2.3 mm; abdomen length ~ 1.7 mm. Genitalia visible in dorsal and ventral view; tergum 9 in dorsal view nearly pentagonal, with concaved anterior margin and convex posterior margin; a pair of long digitiform sclerites (putative gonocoxites 9 or gonocoxites + gonostyli 9) present beneath tergum 9, posterolaterally directing in natural condition (the right one with distal half incurved due to preservation condition), proximally broad, distally with a spinous projection; ectoproct nearly as long as but much narrower than tergum 9, posteriorly slightly convex, bearing some long setae.

Materials examined. EMTG BA-001202: amber piece preserving a complete adult female of N. electroburmica ; it is polished in the form of a suboblong cabochon, transparent, with length×width about 21.3× 8.1 mm, height about 8.0 mm. EMTG BA-002164: amber piece preserving a couple (a male and a female) of N. electroburmica , with bodies mostly preserved except for distal parts of heads, distal parts of male and female genitalia; it is polished in the form of an elliptical cabochon, transparent with numerous particles and bubbles, with length×width about 27.0× 17.2 mm, height about 10.5 mm. PCXJ BA-0004: amber piece preserving a complete, just emerged, adult male of N. electroburmica , and two psocopterans; it is polished in the form of an ovoid cabochon, transparent, with length×width about 21.8× 16.7 mm, height about 5.3 mm.

Remarks. It is notable that the two females of N. electroburmica herein examined greatly differ from each other in body size. The forewing length of female specimen EMTG BA-001202 is 4.1 mm, while in the female specimen EMTG BA-002164 the forewing is 7.6 mm long. However, we could not find any other morphological differences between them. Thus, we tentatively identify them to be a same species. If this identification is verified, the size (i.e. forewing length ≤ 6.0 mm) could not be a constant diagnostic feature to distinguish all nanoraphidiine species from other mesoraphidiids.

We also tentatively identify a just emerged male to be N. electroburmica because of the head with portion posterior to compound eyes nearly equal in length to the length of eye, the short antennae, and the presence of only one forewing discoidal cell, although the ocelli and the diagnostic trifurcate MA are invisible in this specimen.

Key to species of Nanoraphidiini based on non-wing characters (modified from Pérez-de la Fuente et al. 2012)

1. Compound eye shorter, equal, or not much longer than head posterior to eyes; antenna with a low number of flagellomeres (≤ 30)................................................................................................. 2

- Compound eye longer than head posterior to eyes; antenna elongate, with a high number of flagellomeres (≥ 38)..................... 6

2. Head ovoid; compound eye shorter or equal than head posterior to eyes; antenna with less than 26 flagellomeres; metatibia without process at its midpoint........................................................................... 3

- Head quadrangular; compound eye slightly longer than head posterior to eyes; antenna with 26 flagellomeres; metatibia with a process at its midpoint (Pérez-de la Fuente et al. 2010: fig. 4)...................................................................................... .. Cantabroraphidia marcanoi Pérez-de la Fuente, Nel, Peñalver & Delclòs, 2010

3. Compound eye not distinctly shorter than head posterior to eyes; ocelli positioned between posterior half of compound eyes ( Fig. 12 A).......................................................................................... 5

- Compound eye distinctly shorter than head posterior to eyes; ocelli, if present, positioned between anterior half of compound eyes (Pérez-de la Fuente et al. 2012: fig. 8)................................................................ 4

4. Pronotum slightly shorter than head and much shorter than meso- plus metathorax ( Martynov 1925: fig. 7)............................................................................... Grimaldiraphidia parvula ( Martynov, 1925)

- Pronotum slightly longer than head but slightly shorter than meso- plus metathorax (Pérez-de la Fuente et al. 2012: fig. 8).................................... Amarantoraphidia ventolina Pérez-de la Fuente, Peñalver, Delclòs & Engel, 2012

5. Compound eye nearly as long as head posterior to eyes; antenna longer than head length; posterior border of head without a collar-like lip ( Fig. 12 A).............................................. Nanoraphidia electroburmica Engel, 2002

- Compound eye apparently slightly longer than head posterior to eyes; antennae shorter than head length; posterior border of head with a collar-like lip (Grimaldi 2000: fig. 1).......................... Grimaldiraphidia luzzii (Grimaldi, 2000)

6. Clypeus slightly shorter or equal than length of compound eye; all tibiae swollen ( Fig. 1 C).......................... 7

- Clypeus slightly shorter than half length of compound eye; pro- and mesotibiae swollen, but metatibiae slender ( Fig. 7 A).. 10

7. Clypeus prolonged, rostrum-like, as long as compound eye; antenna moderately elongate, with ~40 flagellomeres ( Fig. 5 D; Pérez-de la Fuente et al. 2012: fig. 11).................................................................... 8

- Clypeus not distinctly prolonged, slightly shorter than compound eye; antenna extremely elongate, with 100 or more flagellomeres ( Figs. 1 , 3 )............................................................................... 9

8. Ocelli present; bilobed extensions of third tarsomere with distal digitiform processes (Pérez-de la Fuente et al. 2012: fig. 11).................................... Alavaraphidia imperterrita Pérez-de la Fuente, Peñalver, Delclòs & Engel, 2012

- Ocelli absent; bilobed extensions of third tarsomere without distal digitiform processes ( Fig. 5 )................................................................................................. Rhynchoraphidia burmana sp. nov.

9. Head length 0.6–0.8 mm; antenna nearly twice as long as body, with ~100 flagellomeres ( Fig. 1 A)............................................................................................... Dolichoraphidia aspoecki sp. nov.

- Head length 0.3–0.4 mm; antenna ~2.5 times as long as body, with more than 100 flagellomeres ( Fig. 3 A).......................................................................................... Dolichoraphidia engeli sp. nov.

10. Compound eye ~2.0× length of head posterior to eyes ( Bechly & Wolf-Schwenninger, 2011: fig. 5)......................................................................... Lebanoraphidia nana Bechly & Wolf-Schwenninger, 2011

- Compound eye ~4.0× length of head posterior to eyes ( Fig. 7 A).......................... Burmoraphidia reni sp. nov.

Figures

FIGURE 1. Dolichoraphidia aspoecki gen. et sp. nov. A. Holotype EMTG BA- 001002, habitus in dorsal view; B. Same specimen, habitus in lateral view; C. Same specimen, head and thorax in lateral view; D. Paratype EMTG BA- 002179, habitus in dorsal view; E. Paratype EMTG BA- 002253, habitus in dorsal view. Scale bar = 1.0 mm.

FIGURE 3. Dolichoraphidia engeli gen. et sp. nov. A. Holotype EMTG BA- 001300, habtius in dorsal view; B. Same specimen, fore- and hindwing; C. Same specimen, ovipositor in ventral view; D. Same specimen, drawing of ovipositor in ventral view; E. Paratype EMTG BA- 001252, habitus in dorsal view. Arrows indicating pterostigmal crossvein. Scale bar = 1.0 mm.

FIGURE 5. Rhynchoraphidia burmana gen. et sp. nov., holotype EMTG BA- 002256. A. Habitus in dorsal view; B. Head and thorax in dorsal view; C. distal parts of left wings; D. Drawing of head and prothorax in dorsal view. Arrow indicating pterostigmal crossvein. Scale bar = 1.0 mm.

FIGURE 7. Burmoraphidia reni gen. et sp. nov., female. A. Holotype EMTG BA- 001272, habitus in dorsal view; B. Paratype EMTG BA- 002135, habitus in dorsal view; C. Paratype EMTG BA- 002260, habitus in dorsal view; D. Paratype EMTG BA- 0 0 2254, habitus in dorsal view. Arrows indicating pterostigmal crossvein. Scale bar = 1.0 mm.

FIGURE 12. Nanoraphidia electroburmica Engel, EMTG BA- 001202. A. Habitus in dorsal view; B. Drawing of fore- and hindwing; C. Drawing of female genitalia, lateral view; D. Drawing of female genitalia, dorsal view. T: tergum; S: sternum; gst: gonostylus; op: ovipositor; e: ectoproct. Scale bar = 1.0 mm.

FIGURE 13. Nanoraphidia electroburmica Engel. A. EMTG BA- 002164, habitus (left: male; right: female); B. PCXJ BA- 0 0 0 4, habitus in dorsal view; C. Same specimen, male genitalia in dorsal view; D. Same specimen, drawing of male genitalia in dorsal view; E. Same specimen, male genitalia in ventral view; F. Same specimen, drawing of male genitalia in ventral view. Arrows indicating putative gonocoxites 9 or gonocoxites + gonostyli 9. T: tergum; e: ectoproct. Scale bar = 1.0 mm (A – B) and 0.5 mm (C – F).