Massalongia bachmaieri Moehn , 1958

Elsayed, Ayman Khamis, Skuhrava, Marcela, Ohta, Kazuki, Yoshida, Satoshi & Tokuda, Makoto, 2020, Revision of the birch-associated genus Massalongia (Diptera, Cecidomyiidae), with description of a new species from Japan and a taxonomic key to worldwide species, ZooKeys 958, pp. 1-27 : 1

Massalongia bachmaieri Moehn, 1958

Description.

Head (Figs 25-27 ). Eyes separated on vertex by diameter of 0.0-1.5 facets. Frons with 3-9 setae (n = 6). Mouthparts: labrum with 8-17 short setae (n = 9), hypopharynx pointed, mostly microtrichose; labellum with 4-5 stout setae (n = 5) laterally. Antenna: scape and pedicel with few ventral setae.

Thorax (Figs 28 , 29 ). Wing 2.10-2.25 mm long in males (n = 4), 2.10-2.30 mm long in females (n = 4). Anepimeral setae 3-6 (n = 6).

Female abdomen (Figs 30-32 ). Ovipositor: protrusible portion ca. 1.2 as long as tergite VII, with dorsal sclerite on posterior 2 thirds; cerci elongate-ovoid, with dorsal setae on base, and scattered setae apically.

Male abdomen. Tergite VIII with posterior row of setae. Terminalia (Figs 33-35 ): gonostylus with pointed denticles; cerci base with setae; cerci with setae on apical margin; hypoproct entire, slightly notched, narrowed after basal third; aedeagus shorter than cerci and hypoproct, cylindrical in dorsoventral view, wide basally in lateral view.

Pupa (Figs 36-38 ). Head and thorax of exuviae slightly pigmented; abdomen not pigmented. Antennal horns with short, acute, apical protuberances. Two setose lower facial papillae present; 1 asetose and 1 setose lateral facial papillae present on each side. Prothoracic spiracle long, ca. 210 μm, with trachea extending to just before tip. Abdominal segment VIII with 2 setose dorsal papillae. Abdominal terga II-VIII with 2-3 median rows of wider and longer spinules than surrounding ones.

Mature larva (Figs 39-41 ). Orange to red (Bachimaier 1965). Spatula absent. Terminal segment with 6 papillae: 2 tiny corniform and 4 setose papillae.

Material examined.

Lectotype. 1♂ (SMNS): obtained from Möhn collection Nr. 1205. Paralectotypes. 8 larvae collected on 10.iv.1954 from leaf galls on B. nana , Bernrieder Filz; 3♂, 4♀, 2 pupal exuviae in Möhn collection Nr. 1205.

Distribution.

Europe: Germany and Russia ( Gagné and Jaschhof 2017).

Gall and life history.

Massalongia bachmaieri induces parenchymal leaf galls on B. nana (Fig. 42 ). Mature larvae leave the galls and drop to the ground in mid to late October. They overwinter in cocoons that are spun on the fallen leaves. This species has one generation a year ( Möhn 1958; Bachimaier 1965).

Remarks.

Möhn (1958) designated a male specimen as a holotype of M. bachmaieri and two males and a female as paratypes. When we requested the types for this study, we found that all specimens deposited in SMNS were preserved in alcohol. Möhn probably prepared his illustrations of the species from temporary slide mounts and then put the specimens back in alcohol with the others. Because it was not possible to determine Möhn’s holotype and paratypes among these ethanol-preserved specimens, we designated a lectotype and paralectotypes from the permeant slide-mounted specimens we prepared.

Adults of M. bachmaieri are morphologically most similar to M. altaica . See more under M. altaica below.

Figures

Figure 42. Ethanol-preserved leaf gall of Massalongia bachmaieri on B. nana.

Figures 25 - 29. Massalongia bachmaieri. 25 ventral view of mouthparts 26 ventral view of female flagellomere V. 27 ventral view of male flagellomere III 28 wing 29 tarsomere V and acromere. Scale bars: 50 µm.

Figures 30 - 32. Massalongia bachmaieri. 30 - 31 terminal part of female abdomen (arrow in Fig. 31 indicate the dorsal sclerite on the protrusible portion) 32 protrusible portion of ovipositor. Scale bars: 50 µm.

Figures 33 - 35. Massalongia bachmaieri. 33 male terminalia 34 ventral view of gonostylus 35 ventral view of male hypoproct and aedeagus. Scale bars: 50 µm.

Figures 36 - 38. Pupa of Massalongia bachmaieri. 36 ventral view of head 37 prothoracic spiracle 38 dorsal view of terminal part of abdomen (arrows indicate dorsal spines). Scale bars: 50 µm.

Figures 39 - 41. Larva of Massalongia bachmaieri. 39 ventral view of prothoracic segment 40 ventral view of terminal abdominal segments 41 dorsal view of terminal abdominal segments. Scale bars: 50 µm.