Schizomyia uechiae 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 : 354-358

Schizomyia uechiae Elsayed & Tokuda , sp. nov.

Description. This new species resembles S. broussonetiae except for the following characters:

Head ( Figs. 15–17 ): Compound eyes almost connate, eye bridge 6–8 facets long, facets rounded. Fronto-clypal setae 14–17 (n = 3). Palpal first segment ca. 30.3 µm (28–35 µm), second ca. 43.8 µm (40–48 µm), third ca. 68.8 µm (57–76 µm), fourth ca. 79.5 µm (66–91 µm) (n = 4). Antenna: male flagellomeres cylindrical, deeply constricted after basal third.

Thorax ( Figs. 18–19 ): Wing: length 1.4–1.6 mm (n = 2) in female and 1.3–1.6 mm (n = 3) in male. Lateral scutal setae 17–26 (n = 5); anepisternal scales 11–16 (n = 6); anepimeral setae 10–14 (n = 5).

Female abdomen ( Figs. 20–21 ): Tergite VIII without few fine setae on the posterior margin. Sternites II–VI pair of trichoid sensilla situated anterolaterally to the sclerotized sternite; sternites III–VI with additional median pair of trichoid sensilla; sternite VII with two anterior pairs of trichoid sensilla situated on the sclerotized sternite, and scattered setae on posterior two-thirds. Ovipositor: Protrusible needlelike portion about 3.3 times (3.2–3.4 times; n = 2) as long as sternite VII; cerci fused, each lobe with few fine setae apically.

Male abdomen: Sternites II–VI as in female; sternite VII with pair of trichoid sensilla anteromedially on the sclerotized sternite and another pair anterolateral to the sclerotized sternite; sternite VIII with two pairs of trichoid sensilla intersegmentally between sterna VII and VIII. Terminalia ( Figs. 22–23 ): Gonocoxite length about 2.5 times as long as gonostylus. Gonostylus with a few setae on the distal third dorsally, and a cluster of a few setae on basal half and without setae on the distal half ventrally.

Pupa ( Figs. 24–25 ): Antennal bases (antennal horns) short. Prothoracic spiracle about 272 μm (263–281 μm; n = 2) long. Spiracles present on abdominal segments II–VI.

Mature larva ( Figs. 26–28 ): Yellow. Terminal segment with four pairs of papillae: one pair corniform, one pair with short setae situated anterior to corniform ones, one pair with shorter setae situated between corniform papillae, and one pair lateral to corniform papillae. Sternal spatula bilobed with posterior portion about 2.7 times as wide as the base of the anterior portion. One asetose anal papilla present on each side of the anal opening; other two asetose anal papillae situated posterolaterally, each on separate plaque.

Etymology. It is our great pleasure to name this species in honor of our respected colleague Dr. Nami Uechi (National Agriculture and Food Research Organization, Japan) in recognition of her studies on fruit-infesting gall midges including species associated with Ampelopsis (e.g. Uechi et al. 2002, 2004, 2005, 2017; Gagné et al. 2018; Elsayed et al. 2019a).

Holotype: 1♂ ( KUEC): reared by A. K. Elsayed and emerged on 21.vi.2016 from a larva departed from a flower bud gall on A. glandulosa var. brevipedunculata collected by K. Matsunaga from Haruda, Chikushino City, Fukuoka, Japan on 4.vi.2016.

Paratypes: Collected and/or reared from flower bud galls on A. glandulosa var. brevipedunculata by K. Matsunaga at type locality, as follows. 1♂, 1♀, 2 pupal exuviae: collected on 4.vi.2016, larvae departed from the galls on 8–13.vi.2016, reared by A. K. Elsayed, emerged on 23.vi.2016; 6 larvae: collected on 4.vi.2016, departed from the galls on 7.vi.2016; 6 larvae: collected on 20.vi.2014, departed from the galls on 24.vi.2014; 1♂: emerged on 25.vi.2014; 1♀: emerged on 11.vii.2014.

Distribution. Japan: Kyushu, Fukuoka Prefecture.

Gall and life history. Schizomyia uechiae induces flower bud galls on Ampelopsis glandulosa var. brevipedunculata . The mature larvae leave galls in the beginning of June to pupate in the soil and the adults emerge during the period from the end of June to July.

Remarks. Schizomyia uechiae is close to S. calathidiphaga , S. clematidis , S. spiraeae , S. veronicastrum and S. paederiae because all these species share deeply constricted male flagellomeres ( Kovalev 1964; Fedotova 2002; Elsayed et al. 2018a). Schizomyia uechiae can be separated from S. calathidiphaga and S. paederiae by the following features: the ovipositor is shorter (protrusible needlelike portion about 3.3 times as long as sternite VII, but about 4.5 and 4.8 in S. calathidiphaga and S. paederiae , respectively); the larva of S. uechiae has inner group of lateral papillae of two setose papillae, while two setose and one asetose papillae in S. calathidiphaga and S. paederiae ; the larva of S. uechiae has two corniform and six setose terminal papillae, while the other two species have two corniform, two asetose and four setose terminal papillae. In addition, the larva of S. uechiae has a developed pair of dorsal lobes on abdominal segment VIII, while S. paederiae does not. The adults of S. uechiae can be separated from S. clematidis , S. spiraeae and S. veronicastrum as follows: empodia shorter than tarsal claws, while empodia are longer than claws in S. clematidis and S. spiraeae , and as long as claws in S. veronicastrum ; gonostylus tooth is mostly covering the apical margin in S. uechiae , but it is covering only the posteroapical margin in the other species. In addition, male of S. uechiae has a much narrower hypoproct than S. clematidis .

The anterolaterally situated pair of trichoid sensilla has been reported only from six species of Schizomyia , namely S. achyranthesae , S. asteris , S. diplocyclosae , S. castanopsisae , S. solidaginis and S. usubai ( Elsayed et al. 2018a) , in addition to S. broussonetiae . In the present study, we found that S. uechiae and S. paederiae (A.K. Elsayed, personal observation, 2019) have an anterior pair of trichoid sensilla medially on the sternites and another pair located laterally anterior to the sternite. This indicates that the laterally situated pair of trichoid sensilla anterior to the sclerotized sternite is not shifted from the sclerotized sternite and their origin is obscure. Careful examination of the abdominal morphology of gall midges with special attention to the intersegmental and pleural areas is needed to determine the origin of these trichoid sensilla and their taxonomic importance.

Figures

FIGURES 15–19. Schizomyia uechiae n. sp. 15. Head. 16. Ventral view of male flagellomere V. 17. Ventral view of female flagellomere V. 18. Wing. 19. Tarsomere V and acromere.

FIGURES 20–21. Schizomyia uechiae n. sp. 20. Terminal part of female abdomen (red arrows indicate the anterolateral trichoid sensilla, and black arrows indicate median trichoid sensilla on sternites). 21. Ovipositor apex. Scale bars = 50 µm.

FIGURES 22–25. Schizomyia uechiae n. sp. 22. Male terminalia, excluding hypoproct. 23. Male hypoproct. 24. Ventral view of pupal head. 25. Prothoracic spiracle in pupa. Scale bars = 50 µm.

FIGURES 26–28. Larva of Schizomyia uechiae n. sp. 26. Ventral view of prothoracic segment. 27. Terminal larval segments dorsally. 28. Ventral view of abdominal segment VIII and anus. Scale bars = 50 µm.