Liogma nodicornis, (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 : 1183

LIOGMA NODICORNIS (OSTEN SACKEN, 1865)

( FIGS 5E , 6E , 16D )

Life history: This species is univoltine ( Alexander, 1920). It commonly occurs in damp, swampy woods, in gorges of creeks and on moist, shaded hillsides. Larvae are found on small patches of Mniaceae mosses along the slope of forest paths, dead tree trunks and detritus underneath.

Oviposition: Females deposited eggs singly on the leaves or branches; or lightly attached eggs to the axils of the leaves of Rhytidiadelphus squarrosus ( Alexander, 1915) .

Final-instar larva: Body with green hue, and pale-grey pigmentation patterning on the integument ( Fig. 14A ); brown individuals unknown; dark pigmentation making a narrow band, appearing as an oblique line in lateral view, on abdominal segments I–VII, but absent on cuticular lobes; pigmented area larger on posterior body segment. Larval trunk cylindrical. Integumental surface smooth. Prothorax with two pairs of dorsal, lateral and ventral lobes. Meso- and metathorax with two pairs of dorsal lobes, anterior pair small and conical, and posterior pair bearing single, small, tooth-like auxilliary outgrowth at the front; two pairs of lateral lobes, anterior pair larger and posterior pair conical and smaller; two pairs of ventral lobes. Dorsal lobes of abdominal segments short, apices sharply pointed backwards ( Fig. 5D ): abdominal segment I with two pairs, anterior pair conical, bearing a tiny tooth at the front, posterior pair longer, with a small tooth at the front; abdominal segments II–VII with four pairs of lobes, posterior two bearing a small toothlike auxiliary outgrowth at the front. Lateral lobes of abdominal segments conical; three and four pairs on segment(s) I and II–VII, respectively. Ventral lobes small, three and five pairs on segment(s) I and II– VII, respectively. Anal segment with one pair each of dorsal, dorsomedial lobes; two pairs of ventral lobes, anterior pair papilla-like; four anal papillae present. Spiracular field with hair fringe. Elongated cuticular lobes internally containing tracheal branches.

Host-plants: Larvae are reared on Rhizomnium punctatum (Hedw.) T.J.Kop. ( Bryales : Mniaceae ) and Hypnum cupressiforme Hedw. ( Hypnales : Hypnaceae ) ( Brodo, 1967; Byers, 2002). This study confirms that larvae can also be reared on Rhizomnium appalachianum T.J.Kop. and Plagiomnium ciliare (Müller Hal.) T.J.Kop. , Pl. cuspidatum and Pl. drummondii (Bruch & Schimper) T.J.Kop. ( Bryales : Mniaceae ).

Figures

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 6. Comparative morphology of dorsal elongated cuticular appendages on abdominal segment in cylindrotomine larvae at late instar. (A) Cylindrotoma japonica. (B) Diogma glabrata. (C) Liogma brevipecten. (D) L. mikado. (E) L. nodicornis. (F) L. serraticornis. (G) Triogma kuwanai. (H) Phalacrocera replicata. For C, E and H, body colour is faded away due to preservation in alcohol. Scale = 1 mm.

Figure 14. Biology and morphology of Diogma glabrata. (A) Final instar larva of D. glabrata. (B) Later-instar larva feeding on Bryhnia cf. tenerrima (Brachytheciaceae). (C) Characters of anal segment. Abbreviations: dl, dorsal lobe; dm, dorsomedial lobe; vl, ventral lobe. Scale = 1 mm.

Figure 16. Biology and morphology of Liogma mikado, L. nodicornis, L. serraticornis. (A–C) L. mikado. (A) Late-instar larva, lateral view. (B) First-instar larva (scale = 0.5 mm). (C) Early-instar larva on a tuft of Plagiothecium euryphyllum (Plagiotheciaceae). (D) Late-instar larva of L. nodicornis, feeding on Plagiomnium ciliare (Mniaceae). (E–I) L. serraticornis. (E) Late-instar larvae with green hue, feeding on Plagiomnium vesicatum (Mniaceae). (F) Late-instar larvae with brown hue feeding on Mnium lycopodioides (Mniaceae), found in the same population as the individual shown in (B). (G) Habitus of lateinstar, dorsal view; mesoand metathoracic segments are entirely dark and inverted Y-shaped pattern is evident in abdominal segments I–VII. (H) Characters of head. (I) Characters of anal segment. Black arrows indicate papilla-like, anterior pair of the ventral lobes. Abbreviations: anp, anal papilla; dl, dorsal lobe; pr, pronotal ridge; vl, ventral lobe. Scale (except B) = 1 mm.