Clusia, Haliday, 1838

Shen, Shuang, Zhu, Yongqiang, Liu, Chang, Yang, Ding & Xi, Yuqiang, 2023, First records of the druid fly genus Clusia Haliday, 1838 (Diptera, Clusiidae), with two new species from China, Zootaxa 5257 (1), pp. 123-130 : 124-125

Key to the species of Clusia

1. Abdomen mostly black or brown, sometimes with yellow spot..................................................2

- Abdomen mostly yellow, sometimes with blackish spot...................................................... 11

2. Wing with one brown band at the apical................................................................... 3

- Wing with two brown or blackish bands, one slightly beyond middle and the other at apex, connected along costa........ 10

3. Mesonotum and scutellum entirely testaceous, but humeri and ventral margins of notopleura brown.... C. ciliata (Sasakawa)

- Mesonotum with brown or dark transverse markings, pleurae usually with dark transverse markings....................4

4. Mesonotum black and with a pair of brown longitudinal stripes between the dorsocentral and intra-alar seta, interrupted at the transverse suture; fore tibia and tarsus dark brown..................................... C. nigromaculata (Mamaev)

- Mesonotum light yellow or yellowish, and with one or more stripes; fore tibia and tarsus darkish...................... 5

5. Wing in overall forming a “C” shape; mesonotum with a pair of lateral stripes between the dorsocentral and intra-alar seta, not connected to other markings at the anterior end; wide dark stripe extending from propleuron to mediotergite and subscutellum.............................................................................. C. intermedialis (Mamaev)

- Wing without “C” shape spot; mesonotum with tiny dark stripe or without........................................ 6

6. Thorax with six brown stripes............................................................................7

- Thorax less than six brown stripes........................................................................ 9

7. Postocellar setae absent.................................................................. C. sinensis sp. nov.

- Postocellar with one seta............................................................................... 8

8. Surstylus conical, bearing 12-18 spine-like setae and some setulae on inner apical part; pregonite membranous, with two setae.................................................................................... C. sexlineata Frey

- Surstylus without setae on inner and outer face, without spines; pregonite three setae and four setae at the root............................................................................................. C. luteimacula sp. nov.

9. Abdomen shiny, dark brown except tergite 1, and anterior half and median longitudinal line of tergite 2 brownish yellow, anteromedian line on tergites 3-5 obscure, tergite 7 blackish.................................... C. okadomei Sasakawa

- Abdomen, tergite 1 with inverted T-shaped testaceous patch, tergites 2-3 with testaceous median longitudinal stripes, tergite 4 with median stripe on anterior half and posterior margin broadest, tergite 5 with broadly yellowish anterior and posterior margins and the former slightly projected posteriorly at middle................................. C. omogensis (Sasakawa)

10. Thorax shiny, testaceous, with five blackish stripes; leg yellow, ventral sides of femur somewhat darker, fore femur and mid femur, with three rows of setae, of which posterovental series much stronger than those of antero-ventral.................................................................................................. C. japonica (Sasakawa)

- Thorax strong, black; leg with setae of anterior and posterior flexor surfaces of front femora subequal.... C. czernyi Johnson

11. Wing with three brown or blackish bands...................................................... C. tigrina Fallén

- Wing with one or two brown or blackish bands............................................................. 12

12. Wing with two blackish bands, basal half of costal margin yellow, apical half blackish, connecting with the blackish tip of the wing, posterior crossvein surrounded by a blackish cloud.................................... C. occidentalis Malloch

- Wing with one brown band at the apical................................................................... 13

13. Antenna reddish yellow; arista with sparse pubescence......................................... C. lateralis (Walker)

- Antenna yellow, upper edge of postpedicel blackish; arista with obvious pubescence................................14

14. Palpus yellow; thorax dark brown, crescent-shaped stripes on the mesoscutum, from the transverse suture to the scutellum......................................................................................... C. unita Mamaev

- Palpus dark; thorax testaceous, sometimes with brownish dorsocentral stripes................... C. flava (Meigen)