Ablabesmyia Johannsen, 1905

Niitsuma, Hiromi & Tang, Hongqu, 2019, Taxonomic review of Ablabesmyia Johannsen (Diptera: Chironomidae: Tanypodinae) from Oriental China, with descriptions of six new species, Zootaxa 4564 (1), pp. 248-270 : 249-250

Genus Ablabesmyia Johannsen

Ablabesmyia Johannsen, 1905: 135 ; Fittkau 1962: 416; Roback 1971: 345, 1985: 154; Fittkau & Murray 1986: 37; Murray & Fittkau 1989: 42; Niitsuma 2013: 480 ; Cranston & Epler 2013: 61; Oliveira et al. 2013: 5 . Type species: Tipula monilis Linnaeus , by subsequent designation of Johannsen (1907: 400).

Four subgenera, Ablabesmyia s. str., Karelia Roback , Sartaia Roback and Asayia Roback , are currently recognized within the genus ( Roback 1971, 1983, 1985; Murray & Fittkau 1989; Oliveira et al. 2008). The erection of these subgenera is primarily based on the adult stages.

In the generic diagnosis for the adult, Roback (1971: 354) and Murray & Fittkau (1989: 42) wrote, “third palpal segment shorter than second.” Their second and third palpal segments correspond to the third and fourth palpomeres, respectively, in this paper. The adults of A. (Ablabesmyia) bifurca sp. n. and A. (Karelia) kisanganiensis Lehmann, 1981 (q.v.) have the fourth palpomere being distinctly longer than the third. In the adults of A. (Ablabesmyia) huananensis sp. n. and A. (Karelia) daiensis sp. n., the third palpomere is nearly equal to the fourth in the length. Thus, the character is qualified with “usually” for the generic diagnosis.

Murray & Fittkau (1989) used the costal vein ending above the tip of M 3+4 as a discriminator separating the subgenus Sartaia from the subgenera Ablabesmyia and Karelia , but the wing venations of A. (Ablabesmyia) huananensis sp. n. and A. (Ablabesmyia) praegracilis sp. n. described here, as well as Ethiopian A. (Ablabesmyia) rimae Harrison, 1991 (q.v.), resemble that of A. (Sartaia) metica Roback, 1983 .

Oliveira et al. (2008) reared the larvae of A. (Sartaia) metica to describe the immature stages of the monotypic subgenus Sartaia . They (l.c. p. 62) noted as the diagnostic features for the pupa, “It can be separated from other Ablabesmyia species in having shagreen on abdominal tergites consisting of simple spines and thoracic horn with dense, fine, oval-type of reticulation.” However, the pupae of Chinese A. (Ablabesmyia) pectinata sp. n. and Ethiopian A. (Ablabesmyia) rimae also possess abdominal tergal shagreen consisting of simple spines. In Oliveira et al. (l.c.), the pupa of the Chinese species will key to Ablabesmyia s. str. by the thoracic horn apically with a nipple covering a club-shaped aeropyle tube. Harrison (1991: 58) stated that in the Ethiopian species, “The pupal thoracic horn resembles that of A. (Asayia) annulata (Say) , specially in the structure of the sub-apical position and structure of the horn sac neck, but the thoracic comb tubercles and the simple shagreen spinules are unlike those of annulata .” Consequently, the Ethiopian pupa will key to Sartaia in Oliveira et al. (l.c.).

Niitsuma (2013: 496) pointed out that a club-shaped aeropyle tube occurs not only in Ablabesmyia s. str. and Sartaia , but also in Karelia . According to Oliveira et al. (2013), in Neotropical A. gessnerae Neubern , the male has separate dark spots on the wing membrane, no setal tuft on the abdominal tergite VIII and an apically expanded sub-terminal seta on the gonostylus, of which combination is distinctive in Ablabesmyia s. str. ( Murray & Fittkau 1989: 43), and the pupa possesses a T-shaped aeropyle tube on the apex of the thoracic horn, which is proper to Karelia ( Oliveira et al. 2008: 66).

Further, there is another problem between the adult and larva. In Neotropical A. ducke Neubern , A. fazzari Neubern and A. fusariae Neubern , as well as A. gessnerae , the male possesses the features as mentioned above, wing with separate spots, abdominal tergite VIII without lateral setal tufts, and gonostylus with an apically expanded sub-terminal seta, and the larva has two-divided maxillary palpi, a ligula with a concave margin of five pointed teeth and seven apical setae on the procercus ( Oliveira et al. 2013). Thus, the males key to Ablabesmyia s. str. in Murray & Fittkau (1989: 43), whereas the larvae key to Karelia in Cranston & Epler (2013: 62).

Although Oliveira et al. (2013) described 24 new species of this genus from the Neotropical region, they could not place these species on any subgenus. Therefore, the boundary between subgenera is still unclear.