Pseudasphondylia tominagai Elsayed and Tokuda, 2019

Elsayed, Ayman Khamis, Yukawa, Junichi & Tokuda, Makoto, 2019, Pseudasphondylia tominagai, a new gall midge species (Diptera: Cecidomyiidae) inducing flower bud galls on Eleutherococcus spinosus (Araliaceae) in Japan, Biodiversity Data Journal 7, pp. 35673-35673 : 35673

Pseudasphondylia tominagai Elsayed and Tokuda, 2019 sp. n.

Description

Generic synopsis of Pseudasphondylia Monzen, 1955: see Tokuda and Yukawa (2005)

Adult. Head (Fig. 2 a-c) Eye bridge 6-8 facets long, facets rounded. Antenna: scape slightly wider than long, with scattered setae dorsally on the anterior two thirds and the posterior half ventrally; pedicel spheroid, with scattered setae on the anterior half; nodes of flagellomeres setose and microtrichose, with appressed circumfila and short, naked necks; female flagellomeres with two connected rings of circumfila, flagellomere I and II fused, flagellomeres I-IX elongate-cylindrical, becoming noticeably shorter successively, flagellomeres X-XII successively more foreshortened, flagellomere X twice as long as wide, flagellomere XI about 1.2 times as long as wide, flagellomere XII spheroid; male flagellomeres elongate-cylindrical, equal in length, with anastomosing wavy circumfila. Fronto-clypeus with 15-19 setae (n = 6). Palpus with noticeable palpiger, four-segmented, each segment with few setae and scales, first segment shortest (22-32 μm), second about twice as long as first, third about as long as second, fourth about 1.3 times longer than third. Labrum and labella setose and microtrichose.

Thorax: Anepisternum with 20-25 scales; anepimeron with 21-31 setae (n = 6); katepisternum bare. Lengths of leg parts as in Table 1 ; acropods (Fig. 2 d-e): claws bent after midlength, less robust on foreleg than on mid- and hindlegs, empodia slightly shorter than claws, pulvilli diminutive. Wing (Fig. 3 a): length 1.8-1.9 mm (n = 4) in male and 1.9-2.0 mm (n = 4) in female; width 0.88-0.92 mm (n = 4) in male and 0.92-1.04 mm (n = 4) in female; R5 joining C posterior to wing apex.

Female abdomen (Fig. 4 ): Tergites I-VII rectangular, with anterior pair of trichoid sensilla and some lateral setae; tergite I with scales only on posterior half and posterior row of setae; tergites II-VII evenly covered with scales, tergites II-VI with single row of posterior setae; tergite VII with two posterior rows of setae; tergite VIII bare. Sternites II-VII with anterolateral pair of trichoid sensilla; sternites II-VI rectangular, with single row of posterior setae mixed with few scales, anterior two thirds with scattered setae and setiform scales; sternite VII about three times as long as VI, covered with scattered setae and scales. Ovipositor: eversible part with dorsal pair of pseudocerci basally; protrusible part needle-like, pigmented, about 2.7 (2.67-2.75; n = 4) times as long as sternite VII; cerci undifferentiated.

Male abdomen: Tergites I-VII and sternites II-VI as for female; tergite VIII band-like, bare, with no discernible trichoid sensilla; sternites VII-VIII with anterior pair of trichoid sensilla, covered with scattered setae and scales, sternite VII width about as for VI, sternite VIII about 0.7 as wide as VII. Terminalia (Fig. 5 a): gonostylus with setae dorsally and ventrally on distal two thirds; cerci ovoid with setose margins; hypoproct shorter than cerci, bilobed, each lobe with one posterodorsal seta and one ventral seta; gonocoxal lobes about 0.4 times as long as the hypoproct; aedeagus longer than cerci, tapered.

Third instar. Pale yellow, body strongly bowed backwards. Spatula (Fig. 6 a): quadridentate, inner teeth slightly longer than outer two; posterior portion about 3.7 times as long as width of anterior free portion. Three lateral papillae present, two with setae. Three asetose pleural papillae present anteriorly on each side of prothorax. Two pairs of asetose pleural papillae on meso- and metathorax. One pair of asetose pleural papillae on abdominal segments I-VIII. Two sternal papillae on each thoracic segment and abdominal segments I-VII, with setae, except on prothorax without setae. Two pairs of asetose elliptical papillae present anterodorsally on all thoracic and abdominal segments I-VIII. Two pairs of dorsal papillae present, without setae on thoracic segments and only outer pair with setae on abdominal segments I-VII. Terminal abdominal segment with two pairs of terminal papillae, outer pair with large setae and inner pair with minute setae (Fig. 6 b). Four asetose anal papillae present.

Pupa (Fig. 7 a-c). Four cephalic papillae present on tubercle, two with setae. Antennal horns greatly enlarged, tapered and flattened in ventral view, with serrate outer margins. One pair of setose lower facial papillae present. Two pairs of lateral facial papillae present, one pair with minute setae. Prothoracic spiracle elongated, slightly curved, about 320 μm long, with tracheae extending to tip. Abdominal spiracles present on segments II-IV, each spiracle about 0.5 times as long as the prothoracic spiracle. Abdominal terga I-VII with anterior pair of trichoid sensilla, 4-5 rows of spines and two pairs of dorsal papillae, only outer pair with setae; terga VIII with 3-4 rows of spines and two pairs of setose dorsal papillae.

Etymology: The species name, Pseudasphondylia tominagai , honours Mr. A. Tominaga who collected the galls and reared the adults of this species.

Holotype: 1♂ (on slide): reared from flower bud gall on E. spinosus , collected in Misugi, Tsu City, Mie Prefecture, Japan, on 26.05.2018, emerged on 8.06.2018, A. Tominaga leg.

Paratypes: All paratypes (on slides) were reared from flower bud galls on E. spinosus in Japan by A. Tominaga. 4 larvae: galls collected in Misugi, Tsu City, Mie Prefecture on 26.05.2018, dissected on 26.05.2018; 4 larvae: galls collected in Higashi-Osaka City, Osaka Prefecture on 30.04.2018, dissected on 30.04.2018. 7 pupal exuviae, 5♀, 3♂: same data as holotype.

Distribution: Japan, Honshu: Osaka and Mie Prefectures.

Gall and life history: Pseudasphondylia tominagai induces flower bud galls on E. spinosus . The galled flower bud remains closed and reaches a diameter of 2.06-2.38 mm and length of 3.58-4.27 mm (n = 5) when matured. Larvae grow and pupate in the apical third of the galled bud. Third instars were found in the dissected galls in mid-April and adults emerged in late May.

Diagnosis

Amongst the five known Pseudasphondylia species in Japan, P. tominagai can be separated easily from P. neolitseae , P. matatabi and P. elaeocarpi at least by the following characters: narrower wings (Fig. 3 d, e, f), more palpal segments and shape of sternal spatula ( Yukawa 1971, Yukawa 1974, Tokuda and Yukawa 2005). It can be distinguished from P. rokuharensis as follows: wings of P. tominagai are slightly wider (Fig. 3 c); the male of P. tominagai has the hypoproct with shallower-notch and the cerci more rounded and with deeper emargination in between; the female of P. tominagai has a longer ovipositor (the protrusible needle-like part of ovipositor is 2.7 times as long as sternite VII in P. tominagai compared to 1.8 times in P. rokuharensis ) ( Tokuda and Yukawa 2005); the pupa of P. tominagai has four dorsal papillae on abdominal segments I-VII, compared to six dorsal papillae in P. rokuharensis ( Tokuda and Yukawa 2002); the larva of P. tominagai has four setose papillae on the terminal abdominal segment compared to only two in P. rokuharensis . Pseudasphondylia tominagai is closest to P. kiritanii because both species resemble each other in wing shape (Fig. 3 a, b) and larval and pupal morphology; they can be distinguished from each other by the following characters: the male of P. tominagai has the hypoproct narrower than each cercus and with a shallower notch, whereas the hypoproct of P. kiritanii is slightly wider than each cercus and with a deeper notch (Fig. 5 b); and the protrusible, needle-like part of the female ovipositor is slightly longer in P. tominagai (about 2.7 times as long as sternite VII) than in P. kiritanii (about 2.5 times as long as sternite VII).

Figures

Figure 2. Pseudasphondylia tominagai. a. Head; b. Ventral view of female antennal flagellomeres X-XII; c. Ventral view of male flagellomeres X-XII; d. Tarsomere V and acromere of foreleg; e. Tarsomere V and acromere of hindleg. Scale bars = 50 µm.

Figure 4. Terminal part of female abdomen of Pseudasphondylia tominagai n. sp. Scale bar = 50 µm.

Figure 6. Larva of Pseudasphondylia tominagai n. sp. a. Spatula; b. Abdominal segment VIII and terminal segment dorsally. Scale bars = 50 µm.

Figure 7. Pupa of Pseudasphondylia tominagai n. sp. a. Ventral view of head; b. Prothoracic spiracle; c. Dorsal view of abdomen. Scale bars = 50 µm.