Schizomyia achyranthesae 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 : 126-128

Schizomyia achyranthesae Elsayed & Tokuda sp. n. Figs 5-11, 12-17; Table S1

Etymology.

The species name, achyranthesae, is based on the generic name the host plant, Achyranthes bidentata ( Amaranthaceae ).

Type material.

Holotype: 1♂ (KUEC): reared by A. K. Elsayed from a larva obtained from a fruit gall on A. bidentata , collected from Mount Tara, Saga Prefecture, Japan, on 7.x.2015, M. Tokuda leg., the larva departed from gall between 10-19.x.2015 and the adult male emerged on 3.ix.2016. Paratypes: All paratypes were reared from fruit galls on A. bidentata in Japan. 3 larvae: collected from Tokushima City, Tokushima Prefecture on 6.x.2001, M. Yukinari leg., larvae departed from galls on 12.x.2001; 5 larvae: collected from Tokushima City, Tokushima Prefecture on 30.x.2012, J. Yukawa et al. leg., larvae departed from galls on 30.x.2012; 8♀, 4 Pupal exuviae: collected from Takeo City, Saga Prefecture on 10.x.2015, A. Kita leg., larvae departed from galls between 13-19.x.2015, adults emerged on 1.ix.2016; 3♀: collected from Mount Hinokuma, Saga Prefecture on 16.x.2014, A. K. Elsayed & M. Tokuda leg., larvae departed from galls on 22.x.2014, adults emerged in summer 2015; 4 pupal exuviae: collected from Takeo City, Saga Prefecture on 10.x.2015, larvae departed from galls between 13-19.x.2015, adults emerged on 29.viii.2016; 10♂, 6♀: same data as holotype.

Description.

Head (Fig. 5): Compound eyes separated on vertex by a diameter of 0.0-0.75 facets, eye bridge 7-8 facets long, facets hexagonal. Fronto-clypeus with 15-21 setae (n = 6). Labrum and labella setose. Palpus 4-segmented: first segment ca 34 μm, second 1.3 times as long as the first, third 1.5 as long as the second, fourth 1.3 as long as the third. Antenna: scape slightly wider than long, pedicel rounded, flagellomeres I and II partially fused; female flagellomeres I–IX cylindrical with 2 connected rings of circumfila (Fig. 6); distal flagellomeres successively shorter; flagellomere X about as long as wide; flagellomere XI rounded, slightly wider than long; flagellomere XII rudimentary, partially fused with XI; male flagellomeres cylindrical with sinuous circumfila (Fig. 7).

Thorax: Wing (Fig. 8) length 1.60-2.02 mm (n = 6) in female, 1.43-1.73 mm (n = 5) in male: R1 join C before wing midlength, R5 join C just after wing apex, C broken after the conjunction with R5; wing fold present; M3+4 forked with Cu. Tarsal claws untoothed, bent after midlength; empodia shorter than claws, with long setulae apically; pulvilli not discernable (Fig. 9). Anepimeral setae 19-23 (n = 8); mesanepisternum scales 22-38 (n = 6); lateral scutal setae 21-28 (n = 8). Lengths of leg segments as in Suppl. material 1: Table S1.

Female abdomen (Figs 10, 11): Tergites with anterior pair of trichoid sensilla; tergites I–VII rectangular and evenly covered with scales, tergites I–VI with a posterior row of setae and some scattered setae laterally at midlength; tergite VII with 1-2 posterior rows of setae and some scattered setae laterally at midlength; tergite VIII bare, notched laterally, posterior margin with a pair of well-developed dorsal lobes. Sternites II–VI rectangular, bare and less pigmented medially, with the lateral pair of trichoid sensilla situated anterior to the sclerotized sternite, several scattered setae on the anterior half, and 1-2 rows of setae posteriorly; sternite VII about 2.6 times as long as preceding sternites, with anterior pair of trichoid sensilla laterally situated on the sternite and setae covering posterior two-thirds. Ovipositor: protrusible needlelike portion about 4 times as long as sternite VII (Fig. 10); cerci fused, each lobe with few setae (Fig. 11).

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 lateral pair of trichoid sensilla situated anterior to the sclerotized sternite, several setae scattered anteriorly, median membranous bare area and 1-2 posterior row of setae; sternite VIII setose, with lateral pair of trichoid sensilla situated intersegmentally between sterna VII and VIII. Terminalia (Fig. 12): gonocoxite extending ventrally as convex lobe beyond of gonostylus; gonostylus stout, with unfused and compressed denticles, dorsally with setae on distal third, ventrally with a cluster of setae on the basal half. Cerci notched, each cercus with 4 strong setae and a few fine setae. Hypoproct shorter than cerci and aedeagus, bilobed, with a seta on each lobe. Parameres about half length of hypoproct. Aedeagus gradually tapering, acute apex, longer than cerci.

Mature larva (Figs 13-15): Cylindrical, yellow. Number and position of thoracic and abdominal spiracles as in other Asphondyliini (see Möhn 1961); 6 dorsal papillae present on all thoracic segments and abdominal segments I–VII, each with a seta; abdominal segment VIII with 2 dorsal lobes, each with a setose dorsal papilla. Sternal spatula bilobed (Fig. 13) with posterior portion about 3.6 times as wide as the base of the anterior free portion. Two groups of lateral papillae on all thoracic segments, the inner group of 2 setose papillae and the outer group of 2 setose and 1 asetose papillae. Two sternal papillae on each thoracic segment and 4 sternal papillae on abdominal segments I–VIII, all without setae and situated on slight swellings. Ventral papillae each with a seta on meso- and metathoracic segments and on abdominal segments I–VII. Anus situated ventrally, with simple opening and 4 asetose anal papillae (Fig. 14). Two pairs of pleural papillae present on all thoracic segments and abdominal segment VIII, and 3 pairs on abdominal segments I–VII. Terminal segment (Fig. 15) with 2 setose and 2 corniform terminal papillae.

Pupa (Figs 16, 17): Exuviae not pigmented except prothoracic spiracles and dorsal spines of abdomen. Antennal horns short; 2 pairs of cephalic papillae present, a pair with short seta; 2 pairs of lower facial papillae, a pair with seta; 3 lateral facial papillae present on each side, 1 with short seta, 2 without setae. Prothoracic spiracle, slightly curved, 23-29 μm long (n = 6), connected with trachea to the tip. Spiracles present on abdominal segments II–VI. Abdominal terga I–VIII each with anterior pair of trichoid sensilla and 2 pleural papillae; terga I–VII each with 3 pairs of dorsal papillae, only outermost pair with a seta; tergum VIII with a pair of dorsal papillae, each with a seta. Abdominal terga II–VIII each with 3-4 rows of spines on median third.

Distribution.

Japan: Honshu, Shikoku, Kyushu ( Yukawa and Masuda 1996) and Tanegashima Island ( Yukawa et al. 2013).

Gall and life history.

Schizomyia achyranthesae induces subglobular fruit galls on A. bidentata , 5.07-5.17 mm in diameter (n = 5) (Fig. 1) [Gall No. C-246 in Yukawa and Masuda (1996)]. Based on Yukawa and Masuda (1996) and present observations, each gall contains 1-13 chambers and each chamber contains a single larva. The galls appear in September. The mature larvae leave the galls between October and November and overwinter in the soil. The adults of S. achyranthesae emerge during the flowering season of the host plant in August and September.

Remarks.

Schizomyia achyranthesae is distinguishable from the known Schizomyia species, except S. asteris and S. solidaginis , by its shallowly constricted male flagellomeres, lateral position of anterior pair of trichoid sensilla and presence of four larval terminal papillae, as well as two setose papillae in inner group of lateral papillae. S. achyranthesae can be separated from S. solidaginis based on the larval characters as follows: S. achyranthesae possesses a more elongated sternal spatula than S. solidaginis ; the inner group of lateral papillae consists of two setose papillae in S. achyranthesae , but one setose and one asetose papillae in S. solidaginis ; the anal opening is simple in S. achyranthesae , while branched in S. solidaginis . Then, S. achyranthesae can be separated from S. asteris by the following features: female cerci is less divided in S. achyranthesae ; dorsal setae are present on the gonostylus in S. achyranthesae , but absent in A. asteris ; and the gonocoxite is only slightly extends ventrally beyond the gonostylus in S. achyranthesae , and the larval anal opening is simple in S. achyranthesae while branched in S. asteris .