Schizomyia broussonetiae Elsayed & Tokuda, 2019

Elsayed, Ayman Khamis, Yukawa, Junichi & Tokuda, Makoto, 2019, Two new species of Schizomyia (Diptera: Cecidomyiidae) from Japan, with an updated key to larval, pupal and adult Schizomyia in Japan, Zootaxa 4688 (3), pp. 348-360 : 350-353

Schizomyia broussonetiae Elsayed & Tokuda , sp. nov.

Description. Head ( Figs. 3–5 ): Eye bridge 6–7 facets long, facets hexagonal. Frontoclypal setae 12–16 (n = 6). Mouthparts: Labrum and labella setose; hypopharynx pointed apically, with microtrichose margins; palpiger apparent; palpi microtrichose, with numerous setae, first segment shortest, ca. 42.0 µm (33–47 µm), second ca. 62.3 µm (57–70 µm), third ca. 78.0 µm (75–85 µm), fourth ca. 82.5 µm (65–94 µm) (n = 6). Antenna: Scape slightly wider than long, with ventral setae on basal two thirds; pedicel spheroid, with ventral few setae on basal third; flagellomeres I and II partially fused in both sexes; male flagellomeres shallowly constricted.

Thorax: Wing ( Fig. 6 ): length 2.1–2.3 mm (n = 5) in female and 1.6–2.0 mm (n = 4) in male; R 5 joining C posterior to wing apex. Acropods ( Fig. 7 ): Claws bent after midlength; empodia shorter than claws; pulvilli tiny. Lateral scutal setae 23–28 (n = 5); anepisternal scales 5–10 (n = 6); anepimeral setae 9–10 (n = 5); katepisternum bare.

Female abdomen ( Figs. 8–9 ): Tergites with anterior pair of trichoid sensilla; tergites I–VII rectangular; tergite I with posterior row of setae and few scales posteriorly; tergites II–VI evenly covered with scales, with single row of posterior setae and some scattered setae laterally at midlength; tergite VII with double row of posterior setae and some scattered setae laterally at midlength; tergite VIII weakly sclerotized, bare, notched laterally, posterior margin with few fine short setae and a pair of dorsal lobes. Sternites II–VI rectangular, bare and less pigmented medially, with pair of trichoid sensilla situated anterolaterally to the sclerotized sternite, scattered setae anteriorly, and a single row of posterior setae; sternite VII about three times as long as preceding sternite, with anterior pair of trichoid sensilla situated laterally on the sclerotized sternite and scattered setae on posterior two-thirds. Ovipositor: Protrusible needlelike portion about 2.6 times (2.5–2.7 times; n = 4) as long as sternite VII; cerci with few fine setae on each lobe.

Male abdomen: Tergites I–VII as in female; tergite VIII weakly sclerotized medially, with anterior pair of trichoid sensilla. Sternites II–VI as in female; sternite VII with pair of trichoid sensilla situated anterolaterally to the sclerotized sternite, scattered setae anteriorly, bare and less pigmented medially, and 1–2 rows of posterior setae; sternite VIII about half width of VII, setose, with lateral pair of trichoid sensilla intersegmentally between sterna VII and VIII. Terminalia ( Fig. 10 ): Gonocoxite with ventroapical lobe covered apically with strong setae. Gonostylus with compressed comb-like denticles, distal half with setae dorsally, with a few setae on the basal half and a few setae on distal third ventrally. Cerci ovoid, each cercus with two strong and a few fine setae. Hypoproct shorter than cerci, bilobed, each lobe with apical seta. Gonocoxal lobes about half length of hypoproct. Aedeagus longer than cerci.

Pupa ( Figs. 11–12 ): Exuviae not pigmented except prothoracic spiracles and dorsal spines of abdomen. Antennal bases (antennal horns) short; two asetose and two setose cephalic papillae present; two setose and two asetose lower facial papillae present; two asetose and one setose lateral facial papillae present on each side. Prothoracic spiracle short, about 179 μm (163–195 μm; n = 4) slightly curved, with trachea extending to tip. Abdominal spira- cles present on segments II–VI. Abdominal segments I–VIII each with two pleural papillae; segments I–VII each with six pairs of dorsal papillae, only outermost with setae; segment VIII with two setose dorsal papillae.Abdominal terga II–VIII each with 3–4 rows of spines.

Mature larva ( Figs. 13–14 ): Cylindrical, orange. Numbers of spiracles and dorsal and sternal papillae as basic for Schizomyia ( Möhn 1955) . Abdominal segment VIII with two dorsal lobes bearing setose dorsal papillae. Terminal segment with two setose and two corniform papillae. Sternal spatula bilobed, broad with posterior portion about 1.5 times as wide as the base of the anterior portion. Two groups of lateral papillae present: outer group of two setose and one asetose papillae, and inner group of two setose papillae. Sternal papillae situated on slight swellings. Setose ventral papillae present on meso- and metathoracic segments and abdominal segments I–VII. Anal opening simple. Four asetose anal papillae present. Pair of setose ventral papillae present on abdominal segments I–VII.

Etymology. The species name broussonetiae is derived from the host plant genus.

Holotype: 1♂ ( KUEC): reared by A. K. Elsayed and emerged on 3.vi.2017 from a hairy leaf gall on B. papyrifera collected by I. Kogure in Koaigimachi, Maebashi City, Gunma Prefecture, Japan, on 19.ix.2016.

Paratypes: Collected and/or reared from hairy leaf galls on B. papyrifera by I. Kogure at the type locality, as follows. 7 larvae: collected on 23.x.2014, dissected on 5.xi.2014; 3 larvae: collected on 26.x.2015, dissected on 2.xi.2015; 3 larvae: collected on 19.ix.2015, dissected on 3.xi.2015; 1 pupal exuviae & 1♀: collected on 23.x.2014, emerged on 14.iii.2015; 2 pupal exuviae: collected on 23.x.2014, emerged on 17.iii.2015; 1 pupal exuviae: collected on 23.x.2014, emerged on 24.iii.2015; 1 pupal exuviae: collected on 23.x.2014, emerged on 25.iii.2015; 1♂: collect- ed on 23.x.2014, emerged on 19.iii.2015; 1♂ 1♀: collected on 19.ix.2016, emerged on 6.vi.2017; 2♂ 1♀: collected on 19.ix.2016, emerged on 7.vi.2017; 3♀: collected on 19.ix.2016, emerged on 8.vi.2017; 1♀: collected on 19.ix.2016, emerged on 15.vi.2017; 1♀: collected on 19.ix.2016, emerged on 9.vi.2017; 1♀: collected on 19.ix.2016, emerged on 3.vi.2017; 1♀: collected on 19.ix.2016, emerged on 4.vi.2017.

Distribution. Japan: Honshu, Gunma Prefecture.

Gall and life history. Schizomyia broussonetiae forms hairy galls on B. papyrifera leaves ( Fig. 1 ). Most observed galls occur on the lower surface of leaves, but some appear on the upper surface. Mature larvae overwinter within the galls on the fallen leaves and pupate in the galls in the following spring. Adults emerge from the galls in June.

Remarks. Schizomyia broussonetiae is close to the eastern Palearctic species S. asteris , S. achyranthesae , S. diplocyclosae and S. castanopsisae and S. usubai . These share the following features: male flagellomeres are shallowly constricted, the anterior pair of trichoid sensilla are situated anterolaterally to sternites II–VI, the inner group of lateral papillae in larvae is made up of two setose papillae, and the terminal larval segment has two corniform and two setose papillae ( Elsayed et al. 2018a). Schizomyia broussonetiae can be distinguished from the other species by the following features: the ovipositor is shorter (protrusible needle-like portion about 2.6 times as long as sternite VII, while 3.9 (3.8–4.1; n = 4) in S. achyranthesae , 3.0 (2.9–3; n = 4) in S. diplocyclosae , 5.7 (n= 1) in S. asteris , 3.3 (3.1–3.5; n = 6) in S. castanopsisae and 4.7 (4.5–4.9; n = 3) times in S. usubai , , and the larval spatula is shorter and wider (posterior portion of larval spatula about 1.5 as wide as the base of the anterior free portion, but about 3.5 (3.1–3.7; n = 6) in S. achyranthesae , 3.0 (2.8–3.2; n = 4) in S. diplocyclosae , 3.1 (3.0–3.3; n = 6) in S. asteris , 2.8 (2.7–3.0; n = 7) in S. castanopsisae and 3.0 (2.6–3.6; n = 6) times in S. usubai ). In addition, the larva of S. broussonetiae has a simple anal opening, while S. asteris , S. castanopsisae and S. usubai have branched anal openings. The larva of S. broussonetiae has four anal papillae, while S. diplocyclosae has only two.

Figures

FIGURES 3–9. Schizomyia broussonetiae n. sp. 3. Head. 4. Ventral view of male flagellomere V. 5. Ventral view of female flagellomere V. 6. Wing. 7. Tarsomere V and acromere. 8. Terminal part of female abdomen. 9. Ovipositor apex. Scale bars = 50 µm.

FIGURES 10–12. Schizomyia broussonetiae n. sp. 10. Male terminalia. 11. Ventral view of pupal head. 12. Prothoracic spiracle in pupa. Scale bars = 50 µm.

FIGURES 13–14. Schizomyia broussonetiae n. sp. 13. Larval spatula. 14. Terminal larval segments dorsally. Scale bars = 50 µm.

FIGURES 1–2. Galls induced by Schizomyia spp. 1. A leaf gall of S. broussonetiae n. sp. on Broussonetia papyrifera (Moraceae). 2. Red Flower bud galls of S. uechiae n. sp. on Ampelopsis glandulosa var. brevipedunculata (Vitaceae).