Homoneura biumbrata (Loew 1873)

Semelbauer, Marek & Kozánek, Milan, 2014, The immatures of lauxaniid flies (Diptera: Lauxaniidae) and their taxonomical implications, Zootaxa 3780 (3), pp. 401-454 : 410

Homoneura biumbrata (Loew 1873)

Living larvae only moderately dorsoventrally flattened, the distal parts of Malpighian tubules expanded.

Egg ( Figs 3–5 ). Length 0.77–0.79 mm. Scaphoid from lateral view, dorsal side with 4–5 marked ridges, ventral side with ridges suppressed but more numerous. The chorion perforated. Posterior tubercle prominent and asymmetrical from lateral view.

First instar ( Figs 39, 40 ). Length 1.60–1.83 mm. Medially to the mouth hooks flat rounded outgrowths present. The peristomal cirri rather stout. The ventral organ flatwith three digitiform outgrowths.

Cephaloskeleton ( Fig. 163 ). Length 021– 0.25 mm. The mouth hooks with three strong apical teeth; basal part sclerotised, the dental sclerites indistinguishable.

Second instar ( Figs 41 ). Length 1.89–3.27 mm. Facial mask relatively narrow (12 scraping cirri per row). The peristomal cirri rather stout and few in numbers. The lateral of abdominal segments covered by bumps.

Cephaloskeleton ( Fig. 178 ). Length 0.35–0.38 mm. Mouth hooks converging, 2 apical teeth. Intermediate sclerite strong, ventral bridge narrow. Epistomal sclerite shorter than broad, posterior hyaline plate with two symmetric lobes. Ligulate sclerites stalked, converging. Subhypostomal sclerites converging. Dorsal bridge semilunar. Dorsal cornua broader than ventral cornua from lateral view; distal third of ventral cornua hyaline. Cibarium hyaline.

Third instar ( Figs 42–44 ). Length 3.57–4.05 mm. The facial mask relatively narrow (8–15 scraping cirri per row). The scraping cirri in anterior rows either bifid or trifid. The peristomal cirri stout and few in number. Labial lobe large and broad. The first thoracic segment with broad dorsal belt of comb spines. The second and third thoracic segment with narrow belt of comb spines and laterally with bumps. The anterior spiracles fan-shaped with 5 papillae. The processes of anal division poorly yet clearly developed. The posterior spiracles on stout short sprouts, the peristigmatic tufts small and simple.

Cephaloskeleton ( Fig. 193 ). Length 0.59 mm (n=1). Mouth hooks converging. Intermediate sclerite robustly built, ventral bridge narrow. Epistomal sclerite narrow with posterior hyaline process. Ligulate sclerites as converging vertical plates. Subhypostomal sclerite as converging arms. Rami and parastomal bars rather thick. Dorsal bridge semilunar. Dorsal cornua broader than ventral ones. Distal third of ventral cornua hyaline. Cibarium hyaline.

Figures

FIGURES 1 – 8. Eggs of Cnemacantha muscaria, Homoneura biumbrata and H. limnea. 1. C. muscaria, dorsal view. 2. Same, detail of egg chorion. 3. H. biumbrata, dorsal view. 4. Same, lateral view of posterior tubercle. 5. Same, detail of the egg chorion. 6. H. limnea, ventral view. 7. Same, detail of the posterior tubercle. 8. Same, detail of the egg chorion.

FIGURES 39 – 44. Homoneura biumbrata, first (39, 40), second (41) and third (42 – 44) instars. 39. Cephalic segment. 40. Detail of the ventral organ, lateral view. 41. Cephalic segment, ventral view. 42. Cephalic segment, ventral view. 43. Abdominal segments, lateral view. 44. Detail of the integument of abdominal segment. A, antenna; A 3 – A 5, third to fifth abdominal segments; LL, labial lobe; MH, mouth hooks, PC, peristomal cirri; SC, scraping cirri, SC 1, first row of scraping cirri; VO, ventral organ.

FIGURES 162 – 167. Cephaloskeletons of first larval instar, dorsal (top), lateral (middle) and ventral (bottom) view. 162. Cnemacantha muscaria. 163. Homoneura biumbrata. 164. H. limnea. 165. Minettia austriaca. 166. M. fasciata. 167. M. flaviventris. c, cibarium; db, dorsal bridge; dc, dorsal cornua; dmh, distal part of mouth hook; es, epistomal sclerite; is, intermediate sclerite; lb, labrum; ls, ligulate sclerite; smh, stalked part of mouth hook; pb, parastomal bar; ss, subhypostomal sclerite; vb, ventral bridge; vc, ventral cornua; vp, vertical plate.

FIGURES 177 – 182. Cephaloskeletons of second larval instar, dorsal (top), lateral (middle) and ventral (bottom) view. 177. Cnemacantha muscaria. 178. Homoneura biumbrata. 179. H. limnea. 180. Minettia austriaca. 181. M. fasciata. 182. M. flaviventris. a, apodeme of ventral cornu c, cibarium; db, dorsal bridge; dc, dorsal cornua; ds, dental sclerite; es, epistomal sclerite; is, intermediate sclerite; lb, labrum; ls, ligulate sclerite; mh, mouth hook; pb, parastomal bar; r, rami; ss, subhypostomal sclerite; vb, ventral bridge; vc, ventral cornua; vp, vertical plate.

FIGURES 192 – 197. Cephaloskeletons of third larval instar, dorsal (top), lateral (middle) and ventral (bottom) view. 192. Cnemacantha muscaria. 193. Homoneura biumbrata. 194. H. limnea. 195. Minettia austriaca. 196. M. fasciata. 197. M. flaviventris. a, apodeme of ventral cornu; c, cibarium; db, dorsal bridge; dc, dorsal cornua; es, epistomal sclerite; is, intermediate sclerite; lb, labrum; ls, ligulate sclerite; mh, mouth hook; pb, parastomal bar; r, rami; ss, subhypostomal sclerite; vb, ventral bridge; vc, ventral cornua; vp, vertical plate.