Triogma trisulcata
Creators: name: Imada, Yume
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Cylindrotomidae
Triogma
Triogma trisulcata

description: TRIOGMA TRISULCATA (SCHUMMEL, 1829)
(FIGS 3C, 5I)
Life history: Larvae of this species occur in semiaquatic mosses on moorlands, such as those of Hypnum cuspidatum (Brindle, 1967), in stagnant waters on bogs (Brinkmann, 1997). They have also been found in slowly running water and springs (Steinmann, 1907 – 08; Hemmingsen, 1968), and in small alpine streams (Steinmann, 1907 –08; Müller, 1908; Alexander, 1915). According to Haake (1922), the larvae underwent moulting four times until pupation (Haake, 1922); however, his explanation had a contradictory statement. As Haake (1922) noted, stages I, II and III have one, two and no moulting, respectively, which does not make the total of four instars that the author recorded. First-instar larvae were whitish without distinct colour (Haake, 1922). The larva lives among the stems of the aquatic moss Fontinalis antipyretica, to which it clings firmly with two strong chitinised hooks at the caudal end of the body (Haake, 1922). On pupating, it comes to the water surface and remains immobile for the first few days of pupation; after 8–10 days, it becomes more mobile (Haake, 1922).
Egg: Spindle-shaped, circular in cross-section, with a tapered front pole. Pale yellow. Chorionic sculpture elongated and narrow, arranged as irregularly jagged, dotted dash lines; reticulated near micropyle.
Final-instar larva: Length 19 mm (Alexander, 1920). Body colour light green with dark blotches (Alexander, 1920). Prothorax with three pairs of dorsal lobes along pronotal ridge; one pair of lateral lobes; three pairs of ventral lobes as tubercles (Peus, 1952). Meso- and metathoracic segments with each two pairs of dorsal and lateral lobes; lateral and ventral lobes two and three pairs, respectively (Alexander, 1920). Dorsal elongated lobes on abdominal segments shorter than body width in ventrolateral view, c. 1.5 mm in length (Alexander, 1920): abdominal segments II–VII with four pairs of lobes, posteriormost pair longest, bearing three or four teeth-like auxiliary outgrowths at the front (Alexander, 1915, 1920). Lateral lobes on abdominal segments conical; on segments I and II–VII, three and four pairs, respectively, anteriormost pair smallest (Alexander, 1920). Ventral lobes small, finger-shapd (Alexander, 1920). Anal segment with one pair each of dorsal, lateral and ventral lobes. Spiracular field with hair fringe (Alexander, 1920).
Host-plants: Larvae are found on the submerged moss Fontinalis antipyretica (Hypnales: Fontinalaceae), and may also use Hypnum (Hypnales: Hypnaceae) and Amblystegium (Hypnales: Amblystegiaceae) as hosts (Wesenberg-Lund, 1943). Brinkmann (1991) reported that one adult emerged from Mnium hornum Hedw. (Bryales: Mniaceae).
description: Published as part of 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), pp. 1156-1204 in Zoological Journal of the Linnean Society 193 on page 1186, DOI: 10.1093/zoolinnean/zlaa177, http://zenodo.org/record/5752755