Amygdalops bisinus Roháček, 2008

Roháček, Jindřich, 2018, First Anthomyzidae (Diptera) from China: a new genus, six new species and new records, Acta Entomologica Musei Nationalis Pragae 58 (1), pp. 35-76 : 47-50

Amygdalops bisinus Roháček, 2008

( Figs 36–44 , 62 )

Amygdalops bisinus Roháček, 2008: 341 (partim, male only).

Type material examined. HOLOTYPE:, labelled: ‘ THAILAND: Bangkok, Huaykwang , Aug.–Sept. 1962, J. Scanlon –light’ ( USNM, genit. prep.) and ‘ Holotypus, Amygdalops bisinus sp. n., J. Roháček det.2007’ (red label). PARATYPE: VIETNAM: Cuc phuong, Ninh binh, 6.–18.v.1966, 1, Topál leg. ( HNHM, genit. prep.). Paratype with same type label as the holotype but it is yellow and has ‘Paratypus’ instead of ‘Holotypus’. Additional material examined. CHINA: HAINAN I.: Sanya 30 km NE, Sandaozhen env. Xinjiancun, 18°28ʹ44ʺN 109°38ʹ23ʺE, sweeping, 22.v.2016, 1 1 ♀, J. Ševčík leg. ( SMOC, both dissected and after being used for DNA extraction remnants of their bodies are preserved in glycerine in plastic pinned microvials, genit. prep.).

Addition to description. Male. Total body length 1.82–1.96 mm. f 3 with 5–7 short and thickened setae in distal third of posteroventral row but these setae distinctly longer and more widely spaced than in A. sevciki . Wing measurements: length 1.71–1.91 mm, width 0.50–0.54 mm, Cs 3: Cs 4 = 2.05–2.23, r-m\dm-cu: dm-cu = 3.38–3.56. T5 always with small semicircular, pale ochreous to yellowish, anterolateral spot on each side. Preabdominal sterna pale ochreous, contrasting with dark brown terga. Male genitalia as in Figs 32–37 .

Female (first description). Similar to male (for description see ROHÁČEK 2008: 341 and the above addition) but differing as follows. Total body length 2.32 mm (measured in ethanol). f 3 simply setulose, without thickened posteroventral setae. Wing ( Fig. 62 ) with pattern generally paler than in most other Amygdalops species, thus with preapical brownish spot and stripe along R 4+5 faded and less distinct, and area between R 4+5 and C only a little lighter. R 4+5 and M subparallel or slightly converging preapically and then running parallel apically to margin; r-m situated at middle or slightly in front of midpoint of dm cell. Wing measurements: length 2.14 mm, width 0.64 mm, Cs 3: Cs 4 = 2.05, r-m\dm-cu: dm-cu = 3.23. Preabdominal terga wider and more transverse, dark brown but T4 and T5 with small (and short) yellowish white anterolateral spots, those on T4 being distinctly shorter. Preabdominal sterna paler than in male, yellowish white; S1 short, transverse and bare, S2–S5 finely and sparsely setose. S2 and S3 narrow, longer than broad; S4 and S5 wider than S3, about as long as broad; S5 slightly narrower than S6.

Postabdomen ( Figs 38–40 ) relatively short and broad (at 6th segment). T6 large, broad, relatively shortly but not densely setose (with most robust setae at posterior margin), dark brown with small pale-pigmented anterolateral areas being medially connected by transverse stripe ( Fig. 38 ). S6 whitish yellow, relatively large although narrower than T7, with fine and sparse setae ( Fig. 40 ). T7 transversely suboblong, much narrower and darker brown than T6, anteriorly with pale-pigmented emargination, and covered by dense short setae in posterior half ( Figs 38, 39 ). S7 of distinctive shape with rounded sides, brown-pigmented and finely setose only in middle third; its anterior third pale and micropubescent, and posterior third also pale-pigmented but bare ( Figs 39, 40 ). T8 transversely suboblong and flat ( Fig. 38 ), smaller and paler than T7, with sparse fine setae at posterior margin. S8 ( Figs 39, 40, 42, 43 ) peculiarly modified and markedly different from those of all relatives, relatively short but of complex shape, with dark inclinate digitiform projection on each side, posteromedially narrowly incised, with crescent- -shaped dark pigmentation and finely setose in middle part, and its pale-pigmented dorsolateral parts with more robust micropubescence. Internal sclerotization of genital chamber very weak, largely unpigmented and poorly visible; annular sclerite many times twisted, thicker and best recognized ventrally ( Fig. 43 ); vaginal part of chamber provided with minute thorn-like spines near genital opening ( Figs 42, 43 ). Ventral receptacle ( Fig. 41 ) submembranous, vesiculate but terminally projecting in a beak-shaped process. Spermathecae shortly pear-shaped ( Fig. 44 ), narrowed at duct insertion, with relatively dense and short irregular spines inserted on basal half of spermatheca; duct cervix poorly developed and short. T10 ( Fig. 38 ) small and relatively short, pale, somewhat darkened only laterally, centrally with a spot of sparse and fine micropubescence and with a pair of longer setae. S10 ( Fig. 40 ) slightly wider and darker than T10, micropubescent, with setulae at posterior margin. Cerci ( Figs 38, 39 ) relatively small and short, micropubescent, finely and shortly setose.

Discussion. As noted above, the original description of Amygdalops bisinus Roháček, 2008 involved a mixture of two species, A. bisinus and A. sevciki sp. nov., and the female described as this species belonged to the latter species. Therefore, the interpretation of A. bisinus is corrected above, with the first description of its true female. The knowledge of the female postabdominal structures also helped to clarify the relationships of A. bisinus . Especially, the pyriform spermathecae with thick spines indicate a closer affinity to some species of the A. nigrinotum subgroup of ROHÁČEK (2008), particularly to A. nigrinotum Sueyoshi & Roháček, 2003 and A. geniculatus de Meijere, 1916 . It also shares larger basal sclerite of postgonite with A. nig- rinotum (cf. ROHÁČEK 2008: Fig. 104). The relationships of A. bisinus cannot be solved definitively this time inasmuch as the male of A. geniculatus is unknown and A. bisinus displays some peculiar modifications in the male hypandrial complex (posteroventrally expanded hypandrium and caudal process of transandrium in particular, see Figs 35, 36 ) as well as in the formation of the female S8 ( Figs 42, 43 ) which is unique within the genus Amygdalops .

Differences between A. bisinus and the externally (including the form of the gonostylus) similar A. sevciki are stressed below under the latter species. A. bisinus can also be distinguished from the latter species in having differently modified posteroventral setae on the male f 3, small pale lateral spots on T 5 in the male and on T4 and T 5 in the female, a distinctively formed female S7 and pyriform spermathecae. However, the peculiarities in the male hypandrium and female S8 are the best diagnostic characters of A. bisinus .

Biology. Largely unknown because of the small number of recorded specimens. The holotype was collected at a light and the pair from Hainan I. was swept together with a pair of A. sevciki from low vegetation under longan ( Dimocarpus longan Lour. , Sapindaceae ) trees ( Fig. 65 ). The few known specimens were collected in May, August and September.

Distribution. Known only from three neighbouring countries in the Oriental Region: Thailand, Vietnam ( ROHÁČEK 2008) and China (Hainan I.) (first record).

Figures

Figs 32–37. Amygdalops bisinus Roháček, 2008, male holotype (Thailand). 32–33 – external genitalia (32 – caudally; 33 – laterally); 34 – gonostylus, lateroventrally (widest extension); 35 – hypandrial complex, laterally; 36 – transandrium, caudally; 37 – aedeagal complex, laterally. Scales = 0.05 mm (Fig. 34), 0.1 mm (others). Adapted from ROHÁČEK (2008: Figs 26–31).

Figs 38–44. Amygdalops bisinus Roháček, 2008, female (China: Hainan I.). 38–40 – postabdomen (38 – dorsally; 39 – laterally; 40 – ventrally); 41 – ventral receptacle, laterally; 42–43 – S8 (micropubescence omitted) and associated structures in posterior part of genital chamber (42 – laterally; 43 – ventrally); 44 – spermathecae. Scales = 0.1 mm (Figs 38–40), 0.05 mm (others).

Figs 62–67. Amygdalops and Epischnomyia species and their habitats. 62 – A. bisinus Roháček, 2008, female (China: Hainan I.), wing (length 2.1 mm); 63 – A. sevciki sp. nov., female paratype (China: Hainan I.), wing (length 2.3 mm); 64 – same specimen, detail of costal setosity; 65 – habitat of Amygdalops species in the type locality of A. sevciki; 66 – mating pair of E. merzi Roháček, 2009 (body length of male 3.1 mm, of female 3.8 mm); 67 – habitat of E. merzi in Sichuan: Laohegou. Photos by J. Roháček (62–64), J. Ševčík (65) and S. A. Marshall (66, 67).