Massalongia rubra (Kieffer, 1890)

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 rubra (Kieffer, 1890)

Hormomyia rubra Kieffer, 1890: 199.

Oligotrophus ruber Kieffer, 1895: lxxi.

Description.

Female abdomen. Ovipositor: protrusible portion long; cerci elongated; hypoproct short ( Kieffer 1913b).

Male abdomen. Terminalia: gonostyli with blunt denticles; cerci with rounded tips, shorter than hypoproct; hypoproct notched; aedeagus longer than hypoproct, with enlarged tip (Fig. 52 ) ( Kieffer 1913b).

Mature larva (Figs 53 , 54 ). Spatula bilobed. Dorsal papillae on thoracic segments with tiny setae. Terminal segment with 4 corniform papillae, outer 2 longer than inner ones, and 2 setose papillae.

Pupa. Unknown.

Material examined.

3 larvae: collected in August 1964 from Betula sp. Pěčín Village, Rychnov nad Kněžnou Region, Hradec Králové, Czech Republic, M. Skuhravá leg.

Distribution.

Widespread in Europe and west Asia ( Gagné and Jaschhof 2017).

Gall and life history.

Massalongia rubra induces barely noticeable midrib leaf galls on Betula pubescens Ehrh. and other Betula spp. ( Gagné and Jaschhof 2017; Kieffer 1913b). The females lay eggs on young leaves in May, and most mature larvae leave the galls to overwinter in the ground in October, but some hibernate in the galls ( Skuhravá and Skuhravý 1973).

Remarks.

The larval specimens we described here were collected from similar galls to those described by Kieffer (1913b) for M. rubra and the larval morphology fits Kieffer’s description and illustrations, thus we believe they indeed belong to M. rubra . Types of M. rubra , like most of Kieffer’s types, are considered lost ( Gagné and Jaschhof 2017). We considered using one larva for designating a neotype for the species, but because no adults were reared from these larvae, we cannot be completely certain about their identity and decided to refrain from doing so. Kieffer (1913b) provided an illustration of male terminalia showing that the species is distinctive from the other known species of Massalongia by its long and apically enlarged aedeagus (Fig. 52 ). Because this illustration is important for separating species and it was drawn from the type specimen, future designation of a neotype for the species must rely on reared adults that will enable to compare characters of the male terminalia.

Figures

Figures 52 - 54. Massalongia rubra. 52 male terminalia (after Kieffer 1913 b) 53 spatula 54 dorsal view of larval terminal abdominal segments (a the inner four terminal papillae are folded on the segment b the inner four terminal papillae are unfolded in another specimen). Scale bars: 50 µm.