Bromeloecia balaena Yau and Marshall, 2018

Yau, Tiffany & Marshall, Stephen A., 2018, A revision of the genus Bromeloecia Spuler (Diptera: Sphaeroceridae: Limosininae), Zootaxa 4445 (1), pp. 1-115 : 42-49

Bromeloecia balaena Yau and Marshall sp. n.

(Figs. 9.1–9.14)

Description: Body length 1.5–1.8 mm (males), 1.2–2.0 mm (females).

Head: Length of anterior fronto-orbital seta 0.6x posterior seta. Flagellomere 1 with 4 or more closely contiguous pits on basal outer surface. Genal height 0.6x eye height.

Thorax: Katepisternum with a row of 3–4 smaller anterior setae with dorsal most seta 0.5x and almost level with strong dorsal seta.

Wing: Costa ends at 3/4 of wing length. Angle between costa and R4+5 85°. Distance between radial fork and rm 2x length of r-m; dm-cu subequal to length of r-m and distance between crossveins 0.5x length of dm-cu. Mpseudovein slightly bent towards costa, bent posteriorly to meet level of basal portion in distal one third and ending close to wing margin.

WIPs: Ripple pattern of cell r2+3 distinct, pattern parallel to costa and R2+3 over three quarters of length, distally dipped, narrowest cross section at distal quarter of CS3. Basal angle of distal spot wide, 115°.

Male abdomen and terminalia: Syntergite 1+2, T3 and T4 with long lateral setae, a distinctly long pair of divergent medial setae and multiple short marginal setae in between. Anteroventral arm of synsternite 6+7 thick and truncated, length 0.4x width (measured from sensory setula 6); posteroventral lobe long and curled inwards to abdominal cavity, with anteroventral edge sclerotized. Right side of epandrium without anteroventral process. Surstylus ventral lobe with a row of mollisetae, distal soft ends of mollisetae bent dorsally, dorsomedial lobe long and simple, with few scattered setulae, posterior lobe rounded with a cluster of 6–7 setae.

Hypandrium V-shaped, anterior apodeme extremely reduced, lateral extension plate starts from distal half of posteromedial hypandrial processes; hypandrial arms slender. Ejaculatory apodeme and bulb not observed. Epiphallus quadrate. Distiphallus LFS slender; FDS basally folded, apex reaches back to base of WS; SDS shoehorn-shaped.

Female abdomen and terminalia: T6 narrower than T5, medially usually with a trio of triangularly arranged setae. Each half of T8 large, triangular, with 1 large and 7 smaller setae. S8 laterally triangular, medially shortened. Epiproct almost fully covered with microtrichia, bare surfaces not glossy. Cercus diamond-shaped. Each spermatheca with 1 large apical and 2 small basal pits.

Type specimens: Holotype: ♂: BOLIVIA: La Paz: Coroico, Cerro Uchumachi , 16°12ʹ43ʺS, 067°42ʹ49ʺW, elfin forest, 2550 m, dung pans, 5–6 Apr 2001, S.A. Marshall, debu00189061 ( CBFC).

Paratypes: BOLIVIA: La Paz: same as holotype (21♂, 15♀, CBFC, DEBU); ditto, 5–16 Apr 2001 (7♂, 7♀, CBFC, DEBU). ECUADOR: Pichincha: 22.7 km E Tandapi, moss forest, 8000ʹ, dung trap, 24–29 Jun 1975, S. Peck (26♂, 17♀, QCAZ, DEBU).

Etymology: This name refers to the prominent whale-shaped anteroventral arm of synsternite 6+7 (Latin ‘balaena’: whale).

Comments: B. balaena is known only from dung traps set in mossy elfin forests at high elevations in the Andes of Ecuador and Bolivia. The closely related but more widespread Andean species B. ponsa also occurs at relatively high elevations.