Thinophilus lamellaris Zhu, Yang & Masunaga

Grootaert, Patrick, Tang, Chufei & Yang, Ding, 2015, New species of Thinophilus Wahlberg (Diptera: Dolichopodidae) from mangroves in southern China (Shenzhen), Zootaxa 3956 (4), pp. 547-558 : 551-552

Thinophilus lamellaris Zhu, Yang & Masunaga

( Figs 6–10 )

Thinophilus lamellaris Zhu, Yang & Masunaga, 2006: 146 (figs 4–5).

Diagnosis. Medium-sized species with yellow fore coxa (except for brown base) set with long white bristles. Mesonotum without dull black spots. Wing brownish tinged without spots. Apical part to M1+2 bent on basal third. Legs yellow, but tarsomere 5 of all legs in male brown. Fore femur ventrally with bristles about as long as width of femur, near base sometimes a few long white bristles. Fore tibia with ventral row of spine-like bristles. Surstylus and cercus brown. Cercus with long white apical bristles.

Description. Female. Body length 10.50 mm; wing length 8.50 mm. Body about as long as in male and with similar characteristics. Proboscis evenly strong in female and male. Fore coxa more extensively brownish in female (sometimes up to ¾ of coxa) than in male in which only basal quarter brownish. Fore coxa set with very short and pale bristles while in male anteriorly densely set with long hair-like bristles, longest near base. Fore femur with very short ventral bristles in female while long in male. Fore tibia without ventral row of spine-like bristles like in male. Tarsomeres 2–4 of hind leg more brownish than fore and mid legs in female. Male usually with tarsomere 5 of all legs brown. Sternites with much shorter white hairs than in male. Male. (refer to Zhu et al. 2006 for full description) Body length 9.5 mm; wing length 7.4 mm. Fore leg. Length of femur, tibia and tarsal segments (in mm): 2.80: 2.00: 0.64: 0.32: 0.24: 0.20: 0.28. Mid leg. Length of femur, tibia and tarsal segments (in mm): 2.40: 2.60: 1.20: 0.40: 0.32: 0.20: 0.32. Hind leg. Length of femur, tibia and tarsal segments (in mm): 3.40: 3.60: 1.32: 0.60: 0.40: 0.40: 0.40. Abdomen. Sternite 2 with patch of short white hairs at tip, sternite 3 densely set with long white hairs, sternite 4 also densely set, but slightly shorter hairs. Sternite 5 with some scattered short white hairs on base. Terminalia ( Figs 9–10 ). Cerci large and wide, black, keel-shaped covering surstyli; dorsally fused on basal third, apices free; covered with black bristles, but with pale stronger apical bristle. Tip of both dorsal and ventral surstylus with spine-like black bristles. Phallus long, strap-shaped.

Material examined. CHINA, Guangdong prov., Shenzhen: 5 ♂, 4 ♀, Longgang Yanba, (114°51’E 22°65N), 13.ix.2014, along creek in mangrove (reg. 34011, leg. P. Grootaert & I. Van de Velde); 4 ♂, 9 ♀, same provenance (leg. Y. Zhu, Shanghai); 2 ♂, 13 ♀, Dapeng Peninsula, Luzui, (114°59 E 22°54 N) Yanzao Village, 5.ix.2014 (leg. Hui Dong; CAU).

Discussion. Most characteristics and especially the structure of the male genitalia show that the species found here in Shenzhen corresponds to T. lamellaris . A detailed description of the male was given by Zhu et al. (2006), based on two males found in 1960 in Sanya, Hainan at an altitude of 10 m. The characters of the present specimens also lead to couplet 14 in the key to the Chinese Thinophilus ( Yang et al. 2011) . This species has the fore coxa with long white bristles and the fore tibia with a ventral row of spinules. Thinophilus lamellaris is further characterised by the presence of pale ventral hairs on the fore femur (couplet 16). The new specimens are much larger than the two males described from Hainan, but since there are no other differences we consider them conspecific. In our fresh material some males had indeed a few white ventral bristles on the fore femur as stated in the original description, but other specimens lacked white bristles. Also the length of the ventral bristles in the newly recorded specimens was quite variable. Therefore, we suggest the following couplet to separate T. lamellaris from T. clavatus :

16 Apical section of vein M1+2 undulating beyond Tp; cercus wide................................ T. lamellaris Zhu et al. - Apical section of vein M1+2 almost straight; cercus narrow.................................... T. clavatus Zhu et al.

Figures

FIGURES 6 – 7. Thinophilus lamellaris Zhu, Yang & Masunaga, habitus. 6, male; 7, female.

FIGURES 8 – 10. Thinophilus lamellaris Zhu, Yang & Masunaga: 8, male antenna; 9, hypopygium lateral view; 10, hypopygium dorsal view. Abbreviations: c: cercus; ds: dorsal surstylus. Scale bar = 0.25 mm.