Schizomyia usubai Elsayed & Tokuda

Elsayed, Ayman Khamis, Yukawa, Junichi & Tokuda, Makoto, 2018, A taxonomic revision and molecular phylogeny of the eastern Palearctic species of the genera Schizomyia Kieffer and Asteralobia Kovalev (Diptera, Cecidomyiidae, Asphondyliini), with descriptions of five new species of Schizomyia from Japan, ZooKeys 808, pp. 123-160 : 132-134

Schizomyia usubai Elsayed & Tokuda sp. n. Figs 43-49, 50-55; Table S2

Characters as in S. achyranthesae except for the following:

Etymology.

The species name, usubai, honors the late Mr Shigeshi Usuba who reared adults of this species for the first time.

Type material.

Holotype: 1♂ (KUEC): reared by A. K. Elsayed from a larva obtained from a fruit gall on T. asiaticum , collected from Torinosu, Tanabe City, Wakayama Prefecture, Japan, I. Matoba leg., emerged on 22.v.2017. Paratypes: All paratypes were reared from fruit galls on T. asiaticum in Japan. 4 larvae: collected from Mount Takakuma, Kagoshima Prefecture in 1969, J. Yukawa leg.; 4 larvae: galls collected from Imuta Lake-side, Kedouin, Satsuma-sendai City, Kagoshima Prefecture on 2.xi.1978, S. Sako leg.; 4 pupal exuviae, 2♂, 2♀: collected from Torinosu, Tanabe City, Wakayama Prefecture, I. Matoba leg., reared by A. K. Elsayed, emerged on 18.v.2017; 2 pupal exuviae, 1♀, 2♂: same data as holotype.

Description.

Head (Fig. 43): Compound eyes separated on vertex by a diameter of 0.0-0.5 facets. Fronto-clypeal setae 15-16 setae (n = 4). Palpus: first segment ca 53.5 μm, second about as long as the first, third 1.6 as long as the second, fourth 1.4 as long as the third.

Thorax: Wing (Fig. 46) length 2.03-2.34 mm (n = 4) in female, 1.80-1.95 mm (n = 3) in male. Empodia as long as claws (Fig. 47). Anepimeral setae 10-20 (n = 4); mesanepisternum scales 17-40 (n = 4); lateral scutum setae 19-27 (n = 4). Lengths of leg segments as in Suppl. material 1: Table S2.

Female abdomen (Figs 48, 49): Sternite VII about 2.6 times as long as preceding. Ovipositor: protrusible needle-like portion about 4.5 as long as sternite VII.

Male abdomen: Terminalia (Fig. 50): Gonocoxite with developed, pointed apical lobe extending beyond gonostylus.

Mature larva: Sternal spatula (Fig. 51) with posterior portion about 3.5 times as wide as the base of the anterior free portion. Anus with branched opening (Fig. 52).

Pupa (Figs 54, 55): Prothoracic spiracle 250-350 μm long (n = 6).

Distribution.

Japan: The Izu Islands ( Tokuda et al. 2012b, 2013, Tokuda and Kawauchi 2013) Honshu, and Kyushu ( Yukawa and Masuda 1996).

Gall and life history.

The normal fruit of Trachelospermum asiaticum ( Apocynaceae ) is V-shaped, consisting of a pair of very long and thin seed pods. When the fruits are galled by S. usubai , the apical parts of the fruit become fused and swollen, more or less cat-bell shaped (Fig. 3), about 12-18 mm in diameter and 27 mm in length [Gall No. D-033 in Yukawa and Masuda (1996)]. Each gall consists of 10-25 chambers and each chamber contains 10-25 larvae. Galls mature between late September and October and the larvae depart from galls to overwinter in soil. The adults of S. usubai emerge between late April and July ( Yukawa 1978; Yukawa and Masuda 1996; present study). Similar galls probably induced by this species were found on Trachelospermum gracilipes Hook. f. var. kiukiuense (Hatus.) Kitam. on Tanegashima Island ( Yukawa et al. 2013).

Remarks.

Schizomyia usubai is close to S. asteris , S. achyranthesae , S. diplocyclosae and S. castanopsisae . Schizomyia usubai can be distinguished from S. asteris by a shorter ovipositor (protrusible needle-like portion about 4.5 times as long as sternite VII, while 5.5 times in S. asteris ), longer empodia, and the presence of dorsal setae on gonostyli; from S. achyranthesae and S. diplocyclosae by a longer ovipositor (four and three times as long as sternite VII in S. achyranthesae and S. diplocyclosae , respectively), longer empodia, and branched opening of the larval anus. In addition, larva of S. usubai has four anal papillae, but two in S. diplocyclosae . Schizomyia castanopsisae is very similar to S. usubai , but can be separated by a shorter ovipositor (protrusible needle-like portion about 3.3 times as long as sternite VII, while 4.5 times in S. usubai ), longer empodia, and less compressed circumfila of female flagellomeres.