Polypedilum (Asheum) mayrahu, Pinho & Silva, 2020

Pinho, Luiz Carlos & Silva, Fabio Laurindo Da, 2020, Description of two new species of Polypedilum (Asheum) and immature stages of Polypedilum (A.) curticaudatum (Diptera: Chironomidae), Zootaxa 4759 (2), pp. 179-190 : 182-184

Polypedilum (Asheum) mayrahu sp. n.

( Figure 2 )

Type examined. Holotype male, slide-mounted: BRAZIL, Bahia, Maraú, Praia de Saquaíra , 13°59’16” S 38°57’03” W, 28.ix.2019, CDC trap, AP Amaral col. ( MZSP).

Etymology. The specific epithet refers to Mayrahú, the original name of the type locality in the native language. The name is to be regarded as a noun in apposition

Diagnostic characters. The male of Polypedilum (Asheum) mayrahu sp. n. differs from other species of Polypedilum (Asheum) by having a narrower gonocoxite, longer gonostylus and a very long and sigmoidal apical projection of superior volsella.

Description. Adult male (n = 1). Total length 3.12 mm. Wing length 1.66 mm. Total length / wing length 1.88. Wing length / length of profemur 1.87.

Coloration. Head light brown, palp brown. Thorax light brown with brown pigmentation at posterior area of scutum, postpronotum, postnotum, epimeron II and halter. Legs uniformly light brown. Abdominal tergite I brown, tergites II–VIII light brown with wide (about 0.6 of tergite length) transverse bands. Wings unmarked.

Head. Eyes bare, frontal tubercles absent. AR 1.97; ultimate flagellomere 739 μm long. Temporal setae 15. Clypeus with 17 setae. Tentorium 132 μm long, 27 μm wide. Palpomere lengths (in μm): 37, 45, 117, 117, 164. Third palpal segment 3 sensilla clavata, longest 12 μm.

Wing. VR 1.18. Brachiolum with 1 seta. R with 22 setae; R 1 with 15, R 4+5 with 28 setae, remaining veins bare. Squama with 11 setae. Anal lobe weak.

Thorax. Scutum with low tubercle. Dorsocentrals 10; acrostichals 15; prealars 3. Scutellum with 13 setae, uniserial.

Legs. Scale of foretibia 39 μm long, rounded and without spur. Spur of midtibia 64 μm long, including 49 μm long comb. Spur of hind tibia 69 μm long, including 64 μm long comb. Width at apex of foretibia 44 μm, of midtibia 49 μm, of hind tibia 54 μm. Lengths (in μm) and proportions of legs as in Table 3.

Hypopygium ( Figure 2A, B ). Tergite IX with 6 median setae. Anal tergite band well developed. Laterosternite with 7 setae. Anal point 27 μm long, slender. Phallapodeme 92 μm long, transverse sternapodeme 20 μm long. Gonocoxite 169 μm long. Superior volsella 87 μm long, with 45 μm long sigmoidal apical projection, basal half covered with microtrichia and with 4 inner setae. Inferior volsella slender 90 μm long, with 1 strong apical seta projecting caudad, and 18 orally directed setae. Gonostylus 100 μm long. HR 1.69; HV 3.12.

Female, pupa and larva. Unknown.

Distribution. The new species is known from its the type locality, Maraú, Bahia, Brazil ( Fig. 5 ).

Figures

FIGURE 2. Polypedilum (Asheum) mayrahu sp. n., adult male. A, tergite IX and dorsal aspect of left gonocoxite and gonostylus. B, hypopygium with tergite IX removed, left dorsal aspect, right ventral aspect.

FIGURE 5. Distribution of Polypedilum (Asheum) in neotropical region.