Phalacrocera tipulina, OSTEN SACKEN, 1865

Imada, Yume, 2021, Moss mimesis par excellence: integrating previous and new data on the life history and larval ecomorphology of long-bodied craneflies (Diptera: Cylindrotomidae: Cylindrotominae), Zoological Journal of the Linnean Society 193, pp. 1156-1204 : 1189

PHALACROCERA TIPULINA OSTEN SACKEN, 1865

( FIGS 3E , 5K , 7G–I , 10E , 11E, F , 18C–H )

Life history: This species occur in shaded seepage areas surrounded by deep grasses and clumps of ferns; the larvae occur in stagnant pools with brown and murky water due to the acidification by Sphagnum mosses ( Byers, 2002; this study). The number of moults is unknown. This species can be multivoltine, as larvae with greatly variable sizes are observed both in February and November. The larvae are motionless and hang on shoots of Sphagnum mosses; they pupate near water surface.

Figures

Figure 3. Larvae of Cylindrotominae, showing diverse sizes and forms of elongated cuticular appendages. (A) Cylindrotoma distinctissima, ventral (left), lateral (middle), and dorsal (right) views. (B) Diogma glabrata, oblique ventral (left) and lateral (right) views. (C) Triogma trisulcata, oblique ventral (left) and dorsal (right) views. (D) L. mikado, lateral (left) and dorsal (right) view. (E) Phalacrocera tipulina, dorsal view. A–C are redrawn from Peus (1952).

Figure 5. Schematic diagram illustrating diverse arrangements and numbers of the elongated cuticular lobes in 11 cylindrotomine species. Each diagram represents a simplified larval body, longitudinally grouped into six, based on the patterned arrangements of the lobes: (1) prothorax, (2) meso- and metathorax, (3) abdominal segment I, (4) abdominal segment II, (5) abdominal segments III–VII, and (6) abdominal segment VIII (anal segment). Each square partitioned by double lines in a row denotes the integument on the dorsal (dl), lateral (la), ventral (vl) sides of the corresponding segment(s). Each black dot symbolizes a cuticular lobe, of which position/size in a given space express the relative position/size of the lobe.Anal papillae are not shown. Lobe forms, auxiliary outgrowths, and relative length of segments are not shown here (see each species' own description). Each taxon name is abbreviated. For G and I, diagrams are based on the description in Brodo (1967) and Peus (1952), respectively; caution is needed when these are compared with the species examined herein (A–F, I–K), because the lobe characteristics could be treated differently in the previous studies. For K, a single lobe is present at the location of asterisk (*) only in the abdominal segment VII but not in the other segments.

Figure 7. Ultrastructure of dorsal integument, SEM views. Dorsal integument with elongated cuticular lobes of abdominal segment at larval stage. Cylindrotoma japonica (A–C). (A) General dorsal integument. (B) Dorsal elongated lobe. (C) Ditto, closer view. Liogma brevipecten (D–F). (D) General dorsal integument. (E) Dorsal elongated lobe, lateral side. (F) Ditto, frontal side. Phalacrocera tipulina (G–I). (G) General dorsal integument to which diatoms and debris are sparsely attached. (H) Ditto, closer view. (I) Dorsal elongated lobe. Scales are shown in each image.

Figure 10. Spiracular lobes of cylindrotomine larvae. (A) Cylindrotoma japonica, dorsal view. (B) Liogma nodicornis, caudal view. (C) L. brevipecten, oblique dorso-caudal view. (D) Phalacrocera replicata, caudal view. (E) P. tipulina, caudal view. Abbreviations: anp, anal papilla; dac, accessory dorsal lobe; dl, dorsal lobe; dm, dorsomedial lobe; ha, hair fringe; sp, spiracle; spd, spiracular disc; vl, ventral lobe. Scale = 2 mm.

Figure 11. Ultrastructure of spiracular field of cylindrotomine larvae, SEM views. (A–B) Cylindrotoma japonica. (A) Spiracular field is devoid of hair fringe. (B) Ditto, closer view. (C–D) Liogma brevipecten. (C) Spiracular field is present on the lobe fringed with hairs. (D) Ditto, closer view. (E–F) Phalacrocera tipulina. (E) Spiracular field on the lobe with hair fringe. (F) Ditto, closer view. White arrowheads denote apertures in the central plugs. Scales are shown in each image.

Figure 18. Biology and structures of Phalacrocera replicata and P. tipulina. (A–B) P. replicata. (A) Specimen of lateinstar larva preserved in alcohol, dorsal view. (B) Characteristic lobes in anal segment, lateral view. (C–I) P. tipulina. (C) Specimen preserved in alcohol. (D) Late-instar larva curling its posterior body anchored with anal segment the Sphagnum mosses. (E) Late-instar larva floating near water surface with ventral side up, anchoring its mandibles to a moss shoot. (F) Morphological features of anal segment, oblique lateral view. (G) Ultrastructure of ventral lobe in anal segment, SEM view. (H) Ultrastructure of accessory dorsal lobe, SEM view.Abbreviations: anp, anal papilla; dac, accessory dorsal lobe; dl, dorsal lobe; dm, dorsomedial lobe; spd, spiracular disc; vl, ventral lobe. Scale (except G and H) = 1 mm.