Bombus (Cullumanobombus) trophonius, Prokop, Jakub, Dehon, Manuel, Michez, Denis & Engel, Michael S., 2017

Prokop, Jakub, Dehon, Manuel, Michez, Denis & Engel, Michael S., 2017, An Early Miocene bumble bee from northern Bohemia (Hymenoptera, Apidae), ZooKeys 710, pp. 43-63 : 47-50

Bombus (Cullumanobombus) trophonius sp. n. Figs 1, 2-3, 4-6

Bombus sp. indet.; Prokop and Nel 2003: 166, Dvořák et al. 2010: 36, 78.

Diagnosis.

The new species has a wing shape that is consistent with species of the subgenus Cullumanobombus (Dehon et al. in prep.). Within this group, the fossil has a wing pattern most similar to Bombus (Cullumanobombus) rufocinctus Cresson, a species distributed widely across the Nearctic ( Milliron 1973, Williams et al. 2014), with both species having a similar combination of 3Rs about as long as r-rs but shorter than 4Rs, the basal vein basad 1cu-a, 2Rs arched posteriorly but not as greatly prolonged proximally as in several other species of Cullumanobombus (e.g., Milliron 1971), 1m-cu entering second submarginal cell near midpoint (refer to Discussion). The convex pterostigmal border within the marginal cell, less apically narrowed marginal cell, and less arched 2rs-m minimally serve to distinguish the fossil species from B. rufocinctus .

Description.

♀: Wings and integument black as preserved (taphonomically altered; coloration and membrane pigmentation as in life unknown) (Figs 1-3); forewing total length 14.6 mm; maximum width 5.10 mm (Figs 2, 4, 5); basal vein (1M) weakly arched at base, comparatively straight along length, basad 1cu-a by about vein width, in line with 1Rs; Rs+M originating anteriorad, 1Rs slightly shorter than r-rs; pterostigma short, slightly longer than wide, border inside marginal cell convex, prestigma nearly as long as pterostigma; marginal cell length 5.1 mm, width 1.1 mm, tapering slightly across its length, free portion of cell slightly shorter than portion bordering submarginal cells, apex rounded and offset from anterior wing margin by much more than vein width, not appendiculate; 2Rs strongly arched basally and then gently arched outward, giving second submarginal cell distinct proximal extension; r-rs about as long as 3Rs; 4Rs only slightly longer than 3Rs; three submarginal cells of comparatively similar sizes, albeit third slightly larger than first or second; first submarginal cell length 0.9 mm, width 1.0 mm; second submarginal cell length 1.3 mm, width 0.9 mm; third submarginal cell length 1.6 mm, width 1.2 mm; 1rs-m straight, comparatively orthogonal with Rs; 2rs-m arched distally in posterior half; 1m-cu distinctly angulate anteriorly near M, entering second submarginal cell near cell’s midlength; 2m-cu weakly and gently arched apically, meeting third submarginal cell at cell’s apical fifth of length. Hind wing length 9.4 mm, width 2.6 mm (Figs 3, 6). Preserved portion of thorax and legs difficult to discern and interpret, although portion of metatibial corbicula preserved (basal quarter to third), and most sclerites with numerous, long setae.

♂: Latet.

Holotype.

♀ (caste uncertain, likely a worker), ZD0003, Early Miocene, Most Formation, Clayey Superseam Horizon, Holešice Member (No. 30), Bílina Mine near Bílina, Czech Republic; deposited in the museum collection of the Bílina Mine Enterprises, Bílina, Czech Republic.

Etymology.

The specific epithet is taken from the Greek mythological hero, Trophonius, one of the two brothers who absconded with the treasure of King Hyrieus and who fled into caverns at Lebadaea ( today’s Livadeia in Boeotia). Trophonius is generally associated with bees and the underworld since, according to legend, it was a swarm of bees that led a boy to rediscover his cave, bringing his spirit honor and peace.