Brachineura sphaerica Jiao & Bu, 2018

Jiao, Kelong, Wang, Hao, Wang, Yuanhong & Bu, Wenjun, 2018, Notes on the genus Brachineura Rondani (Diptera: Cecidomyiidae), with description of three new species from China, Zoological Systematics 43 (1), pp. 103-108 : 104-106

Brachineura sphaerica Jiao & Bu , sp. nov. ( Figs 1–6 )

Diagnosis. The new species is characterized in the genus Brachineura by the unique combination of gonostylus with the basal half swollen to be sub-globular, and aedeagus with the width of apex distinctly shorter than half the width of the basal half of gonostylus. It is similar to B. quercina Edwards by gonostylus with the basal half swollen to be sub-globular ( Fig. 5 ), however, B. sphaerica differs by aedeagus with the width of apex distinctly shorter than half the width of the basal half of gonostylus and gonostylus approximately as long as half the length of gonocoxite ( Fig. 5 ), while B. quercina having aedeagus with the width of apex distinctly longer than half the width of the basal half of gonostylus and gonostylus distinctly shorter than half the length of gonocoxite.

Description. Adult. Body colour yellow. Body length 1.00– 1.10 mm; wing length (measured from the base) 0.90– 1.00 mm; wing width 0.40–0.50 mm (n = 3).

Head ( Figs 1–2 ). Eye bridge 3 facets long in the middle of vertex. Palpus sparsely setose, with 3 segments, last two segments longer than first one ( Fig. 2 ). Antenna with 10 flagellomeres; pedicel subglobular, smaller than scape, both densely covered with setae ventrally; node of all flagellomeres subcylindrical, a little broadened subbasally, densely covered with long scales, neck of all flagellomeres extremely shorter; each node with 2 horizontal, appressed, band-shaped circumfila, subapically and subbasally respectively linked by two similar longitudinal circumfila, and 2 whorls of long, strong and irregular setae, one subbasal and one subapical; first and second flagellomeres fused; 3rd male flagellomere ( Fig. 1 ), with the node 2.00–2.10 times as long as wide and the neck 0.9–1.0 times as long as wide, 0.23–0.24 times length of node. Head having a finger-shaped structure with dense setae between the two antenna bases.

Thorax ( Figs 3–4 ). Wing ( Fig. 3 ) hyaline, 2.23–2.24 times as long as wide. Vein Sc weak, C, R 1 and R 5 strong; vein R 1 joining vein C at basal 2/5; vein R 5 bent a little forward in the middle, joining vein C distinctly anterior to wing apex, approximately at distal 1/6; vein Cu unforked and bent backward, vein PCu parallel with Cu. Legs densely covered with narrow scales and sparse setae. Tarsal claw ( Fig. 4 ) toothed on all legs; empodium approximately as long as tarsal claw; pulvillus cylindrical.

Abdomen. Each tergite and sternite densely covered uniformly with scales. First through sixth tergites developed and strip-shaped, with an irregular but mostly single, posterior row of setae, with several pairs of lateral setae, and with one anterior of trichoid sensilla except for the sixth with a double, posterior row of setae; first tergite much shorter than second tergite; seventh and eighth tergites both reduced to one strongly sclerotized, latitudinal and linear band with several scattered setae; second through eighth sternites covered with many scattered lateral and central setae, with one anterior pair of closely set trichoid sensilla; second through sixth sternites sub-rectangular with an irregular but mostly triple, posterior row of setae; seventh sternite shorter than sixth; eighth sternite crescent, much shorter and much narrower than seventh.

Male genitalia ( Figs 5–6 ). Gonocoxite slender, with mediobasal lobes undeveloped and reduced to five separated setae, each inserted in a small, smooth and sclerotized prominence; gonostylus approximately as long as the half length of gonocoxite, with the basal half swollen to be sub-globular and with the distal a little swollen, covered with a few setae and dense microtrichiae, with two short setae located apically on the inner side, toothed apically; cerci separated with a wide depression forming two broad lobes with a few long lateral setae; hypoproct a little longer than cerci, emarginated deeply and widely with a U-shaped depression forming two slender lobes; aedeagus distinctly longer than gonocoxite, gradually tapered from base to middle, with the distal half sub-cylindrical, and with the width of apex distinctly shorter than half the width of the basal half of gonostylus. Female genitalia unknown.

Material examined. Holotype. ♂. China, Heilongjiang, Ning’an, Jingbo Lake , Huluwaizi (43.48°N, 128.55°E; elev. 700 m), 19–20.VII.2001, leg. Jun Li & Yüxia Jiang, Malaise trap, NKUCecid. No. BBM001. Paratypes. 2♂, same data as holotype, NKUCecid. No. BBM002–003 .

Distribution. China (Heilongjiang).

Etymology. The specific name sphaerica means the male gonostylus with the basal half swollen to be sub-globular.

Figures

Figures 1–6. Brachineura sphaerica Jiao & Bu, sp. nov., male. 1. The 3rd flagellomere, dorsal view. 2. Palpus, lateral view. 3. Wing, dorsal view. 4. Fore acropod, lateral view. 5. Genitalia, dorsal view, one gonopod removed. 6. Genitalia, ventral view, one gonopod removed. Scale bars: 1–2, 4–6=20μm; 3=100μm.