Lauxania cylindricornis

Semelbauer, Marek & Kozánek, Milan, 2012, Morphology of preimaginal stages of Lauxania and Calliopum (Diptera: Lauxaniidae), Zootaxa 3346, pp. 1-28 : 23

Lauxania cylindricornis

Egg ( Figs 1, 3 ). Length 0.60–0.71 mm. Chorion of egg with small clusters of perforated windows. Posterior tubercle surrounded by ring of perforated chorion. Chorion of mycropylar pole tufted.

First larval instar ( Fig.6 ). Length: 0.70–1.50 mm. Length of cephaloskeleton: 0.19–0.24 mm ( Fig. 106 ). Five teeth on distal part of mouth hook ( Figs 7 , 37 ). Two digitiform projections of ventral organ ( Fig. 8 ) appear to be longer compared to L. minor .

Second larval instar ( Figs 9–12 ). Length: 1, 07–3, 34 mm. Length of cephaloskeleton: 0.30–0.40 mm ( Fig. 107 ). Probably without reliable differentiating characters.

Third larval instar. Length: 3.28–4.55 mm. The first thoracic segment almost completely covered by spines dorsally ( Figs 26 , 29 ). The second thoracic segment with anterior comb spines, middle spinous area and broad smooth area on posterior margin. The third thoracic segment with similar pattern, but note the hairs on posterior margin ( Fig. 29 ).

Integument of abdominal segments almost completely villous both from dorsal and ventral side ( Figs 30, 32 ). Two pairs of dorsal tubercules not surrounded by smooth area ( Fig. 30 ). Anterior spiracles with 9–10 papillae, the upper-most papilla smaller ( Fig. 27 ).

Length of cephaloskeleton: 0.62–0.68 mm. Cepahloskeleton ( Fig 39 ) not compressed in dorsoventral axis. Dorsoventral axis of mouth hooks meets in acute angle, tips of mouth hooks slightly diverging. Intermediate sclerite straight from lateral view. Pharynx with pigmented transversal strip posteriorly, but in different specimens it can be variously developed. Dorsal edge of ventral cornua pressed inwards between apodeme and vertical plate. Pharynx relatively deep in posterior half.

Puparium. Length 2.97–3.93 mm. Surface more hairy than in L. minor , corresponding to the integument of the third instar. Processes of anal division more well developed than in L. minor ( Fig. 116).

Figures

FIGURES 1 – 4. Eggs of Lauxania cylindricornis and L. minor. 1 – L. cylindricornis, oriented with posterior end to left. 2. L. minor, oriented with posterior end to left. 3. L. cylindricornis, detail of posterior tubercle. 4. L. minor, detail of posterior tubercle.

FIGURES 5 – 8. First instar of L. cylindricornis and L. minor. 5. L. minor, pseudocephalon, ventral view. 6. L. minor, detail of ventral organ. 7. L. cylindricornis, pseudocephalon, ventral view. 8. L. cylindricornis, detail of ventral organ and mouth hook. C, cirri; C 1, first row of cirri; LL, labial lobe; LS, labial sensilla; MH, mouth hook; VO, ventral organ.

FIGURES 101 – 106. Calliopum splendidum, third instar, arrowheads indicate the tubercles. 101. First and second thoracic segment, dorsal view. 102. Third thoracic and first abdominal segments, dorsal view. 103. Abdominal segments, ventral view. 104. Abdominal segments, lateral view. 105. Anal division and last abdominal segments, dorsal view. 106. Posterior spiracles, dorsal view. A 1 – A 7, first to seventh abdominal segments; ACW, anterior creeping welt; AL, ambulatory lobe; AS, anterior spiracle; DP, dorsal process; LCW, lateral creeping welt; LP, lateral process; PCW, posterior creeping welt; PS, posterior spiracles; T 1 – T 3, first to third thoracic segments.

FIGURES 35 – 46. Eggs of Calliopum species, columns from left to right: whole egg oriented with posterior end up; posterior tubercle; mycropyle. 35 – 37. C. aeneum. 35. Left, dorsal view; right, ventral view. 38 – 40. C. elisae. 38. Dorsal view. 41 – 43. C. splendidium. 41. Dorsal view. 44 – 46. C. simillimum. 44. Lateral view.

FIGURES 9 – 12. L. cylindricornis, second instar. 9. Pseudocephalon, ventral view. 10. Pseudocephalon, anterodorsal view. 11. Ventral organ, detail. 12. Anterior spiracle. A, antenna; C, cirri; LL, labial lobe; LS, labial sensilla; MH, mouth hook; MP, maxillary palpus.

FIGURES 107 – 112. Cephaloskeletons of L. cylindricornis (left column) an L. minor (right colum). From the top for each figure: dorsal, lateral and ventral view. 107. L. cylindricornis, first instar. 110. L. minor, first instar. 108. L. cylindricornis second instar. 111. L. minor, second instar. 109. L. cylindricornis, third instar 112. L. minor, third instar. db, dorsal bridge; dc, dorsal cornu; ds, dental sclerite; es, epistomal sclerite; dmh, dentate part of mouth hook; is, intermediate sclerite; lb, labrum; ls, ligulate sclerite; mh, mouth hook; pb, parastomal bar; ph, pharynx; r, rami; smh, stalk part of mouth hook; ss, subhypostomal sclerite; vb, ventral bridge; vc, ventral cornu; vp, vertical plate.

FIGURES 23 – 28. Lauxania cylindricornis, third instar, arrowheads indicate the tubercles. 23. Pseudocephalon, ventral view. 24. Maxillary palpus. 25. Ventral organ. 26. Pseudocephalon and first thoracic segment, dorsal view. 27. Anterior spiracle, anterior view. 28. Medial tubercle on first thoracic segment, dorsal view. A, antenna; C, cirri; CS, pseudocephalon; LL, labial lobe; LS, labial sensilla; MH, mouth hook; MP, maxillary palpus; NS 1, NS 2, first and second additional sensilla; SB 1 – SB 4, first to fourth sensilla basiconica; SC 1 – SC 4, first to fourth sensilla coeloconica; VO, ventral organ.

FIGURES 29 – 34. Lauxania cylindricornis, third instar, arrows indicate borders between segments, arrowheads indicate the tubercles. 29. Pseudocephalon and thoracic segments, dorsal view. 30. Abdominal segments, dorsal view. 31. Anal division, ventral view. 32. Abdominal segments, ventral view. 33. Anal division, dorsal view. 34. Posterior spiracles, posterior view. A 3 – A 5, third to fifth abdominal segments; ACW, anterior creeping welt; AL, ambulatory lobe; AS, anterior spiracle; DP, dorsal process; LP 1, LP 2, first and second lateral process; PCW, posterior creeping welt; MCW, medial creeping welt; PS, posterior spiracles; T 1 – T 3, first to third thoracic segments; VP, ventral process.