Bolitophila warreni, Greenwalt & Blagoderov, 2019

Greenwalt, Dale E. & Blagoderov, Vladimir A., 2019, Review of the fossil record of Bolitophilidae, with description of new taxa and discussion of position of Mangas Kovalev (Diptera: Sciaroidea), Zootaxa 4567 (3), pp. 546-560 : 547-548

Bolitophila warreni sp. nov.

( Figures 1–6 , 12.1)

urn:lsid:zoobank.org:act:D7D7EBC6-FA7D-4C0D-8999-210F4C71D276

Etymology. The specific epithet is derived from the paternal name of Jill Warren, a middle school science teacher from Corvallis, Montana who assisted in the collection of specimens and whose Science Olympiad team won state championships in 2010, 2012 and 2013.

Holotype. USNM 595138 ; deposited in the Department of Paleobiology, National Museum of Natural History ( NMNH), Smithsonian Institution , Washington, District of Columbia.

Type Horizon. Middle Eocene Coal Creek member, Kishenehn Formation.

Type Locality. Disbrow Creek site, Middle Fork of the Flathead River (Pinnacle, Montana).

Diagnosis. R 4 sigmoid, ending in R 1; C ends beyond tip of R 5; tb present, but very short. Stigma very weak. Parameres longer than aedeagus; gonostyli tapering towards apex, simple.

Description. Adult male ( Figure 1 ), body length 4.66 mm. Head black, 0.43 mm long, 0.62 mm high. Eyes not visible. Maxillary palp 0.3 mm long. Antenna brown, at least 3.2 mm long (estimated, middle flagellomeres not preserved), 58 mm and 35 mm wide (first and terminal flagellomeres respectively); flagellomeres ~ 8x longer than wide ( Figures 1 and 2 ). Thorax 1.04 mm long. Mesonotum black/dark brown dorsally, lateroteregite, anepisternum and katepisternum light brown, anepimeron yellow; coxae yellow ( Figure 2 ). Haltere very lightly pigmented, spatulate, approximately 0.9 mm long (visible portions 0.73 and 0.39 mm for right and left haltere respectively), 35 mm and 183 mm wide at midpoints of stem and knob respectively. Wing length 4.6 mm, width 1.33 mm ( Figure 3 ). L/W ratio = 3.46. Wing membrane with microtrichia only. Stigma faint, at the apex of R 1. Vein R 2+3 slightly sigmoid, terminating in costa (Figure 4.1). Sc ending at the level of base of Rs1, sc-r at the level of middle of m-cu. Cell r 1 parallel-sided proximad of R 2+3. C extending only slightly beyond R 5. R 5 and M 1 slightly converging at the apex, M 1 and M 2 rather parallel along most of their extension, except at the very tip, M2 strongly diverging from M1; M 4 and CuA curved basally at apex. Cross-veins r-m and m-cu, and the very base of M3+4 (tb) present, oblique. Length of r-m 0.5x the section M3 and equal to the length of m-cu. A 1 present but distal portion not visible due to folding of the wing. Wing surface covered with microtrichia, anterior margin of wing with spiniform setae approximately 50 mm long. All six legs present, setose ( Fig. 1 ). Length of tibial spurs on fore, mid and hind legs 35, 95 and 155 mm, respectively ( Fig. 5 ). Abdomen brown, setose, length 3.51 mm (including terminalia), 0.45 mm wide at distal tip of gonocoxites. Length of segments 7 and 8 respectively 0.8x and 0.6x of that of segment 6. Male genitalia with tergite 9 and cerci short; gonocoxites 0.45 mm wide, 0.15 mm long; gonostyli with long setae on lateral surface, evenly tapering towards apex and very slightly curved inwards, without visible teeth or branches. Parameres longer than aedeagal complex ( Figure 6 , 12.1).

Remarks. The species seems to be close to B. hybrida (Meigen) group but differs from all known species in combination of shape of gonostyli, length of parameres, presence of the distinct base of M 3+4 (tb) and C running beyond the tip of R 5.

Figures

FIGURE 1. Bolitophila warreni sp. nov., holotype USNM 595138. Scale bar equals 3 mm.

FIGURE 2. Head and thorax of Bolitophila warreni sp. nov., holotype USNM 595138. The arrows denote portions of the antennae. Scale bar equals 1 mm.

FIGURE 3. Right wing of Bolitophila warreni sp. nov., holotype USNM 595138. 1. Photograph. 2. Drawing. Scale bar equals 2 mm.

FIGURE 4. Details of the wing venation of Bolitophila warreni sp. nov., holotype USNM 595138. 1. Right wing vein R 2+3 (arrows). 2. Left wing crossvein tb (long arrow) and vein M 3+4 (arrowhead). Scale bars equal 0.2 mm (1) and 0.5 mm (2).

FIGURE 5. Tibial spurs of Bolitophila warreni sp. nov., holotype USNM 595138. 1. Front leg. 2. Middle leg. 3. Hind leg. Scale bar, applicable to all three photos, equals 0.1 mm.

FIGURE 6. Terminalia of Bolitophila warreni sp. nov., holotype USNM 595138. Scale bar equals 0.2 mm.