Stenochironomus suzanae, Dantas, Galileu P. S., Hamada, Neusa & Mendes, Humberto F., 2016

Dantas, Galileu P. S., Hamada, Neusa & Mendes, Humberto F., 2016, Contribution to the knowledge of Stenochironomus Kieffer (Diptera, Chironomidae) from Brazil: seven new species and description of females and immatures of some previously known species, Zootaxa 4117 (1), pp. 1-47 : 39-40

Stenochironomus suzanae new species

( Figs 29–30 )

Type material. Holotype male, BRAZIL: Amazonas state, Itacoatiara, Madeireira Mil, 02º 46’37.7’’ S, 58º 50’38.3’’ W, 30.IV.09, in decayed wood, G.P.S. Dantas, S.C. Escarpinati ( INPA).

Diagnostic characters. Male: thorax with a somewhat circular patch on anterior portion of lateral vitta, and a poorly defined patch on anterior portion of scutum; scutum strongly projected anteriorly; small spine on apex of scale of frontal tibia; gonostylus robust; setae on inferior volsella not arranged linearly; high value of AR higher than 3.00; superior volsella short and rounded at apex; anal point with a slightly bulbous apex.

Etymology. The species is named in honor of Suzana Escarpinati for her great help during field work.

Male (n = 1). Total length 8.23 mm. Wing length 3.59 mm. Total length/ wing length 2.29. Wing length/ length of profemur 2.13.

General coloration yellowish. Eyes not metallic. Thorax with a somewhat circular patch on anterior portion of lateral vitta, and a poorly defined patch on anterior portion of scutum ( Fig. 29 B). Frontal femur yellowish; frontal tibia dark brown; frontal tarsus light brownish; mid and hind legs yellowish. Wings completely light yellowish. Abdomen with T I–IV with distal portion pigmented.

Head ( Fig. 29 A). AR 3.36. Thirteenth flagellomerum 1.63 mm long. Temporal setae 20. Clypeus with 39 setae. Tentorium, stipes and cibarial pump as in Figure 25 A. Tentorium 239 µm long; 62 µm wide at sieve pore; 40 µm wide at posterior tentorial pit. Stipes 14 µm wide; length not measurable. Palpomere lengths (in µm): 69; 83; 338; 159; 190. Fifth palpomere small.

Thorax ( Fig. 29 B). Acrostichals 16; dorsocentrals 16 in a single row; prealars 9 in two rows. Scutellum with 16 setae in a single row. Anterior edge of scutum rounded and in lateral aspect and markedly projected anteriorly.

Wing ( Fig. 29 D). VR 1.51. Brachiolum with 8 strong setae; 26 sensilla campaniformia. R with 54 setae; R1 with 34 setae; R4+5 with 44 setae; RM with 1 setae; remaining veins bare . Squama with 16 setae.

Legs. Scale of front tibia 72 µm long, with a small spine at apex; spurs of middle tibia 61 µm and 62 µm long; spurs of hind tibia 54 µm and 56 µm long. Apex of fore tibia 103 µm wide, of mid tibia 104 µm wide, of hind tibia 117 µm wide. Lengths (in µm) and proportions of legs as in Table 9.

Hypopygium ( Figs. 29 C, 30A, 30B). Anal point 166 µm long; 36 µm wide at base; 21 µm wide at apex; 15 at 1/3 from apex. Tergite IX with 91 setae, caudal apex rounded in dorsal aspect, with several strong setae. Laterosternite IX with 2 setae. Phallapodeme 179 µm long, nearly S-like; transverse sternapodeme 44 µm long. Gonocoxite 327 µm long; inferior volsella 356 µm long, with 16 setae arranged irregularly; superior volsella 76 µm long, with 5 setae. Gonostylus robust, 272 µm long. HR 1.20; HV 3.02.

Female, pupa and larva unknown.

Systematic remarks. S. suzanae sp. nov. resembles S. aculeatus Borkent by the thoracic pigmentation, but can be distinguished by the high AR valor, the length and form of the superior volsella and by the apex of anal point, that is slightly bulbous in the new species and markedly slender in the other.

Notes on biology of species. This species is known only from the type locality in northern Brazil. The only specimen was obtained from decayed wood and reared in the laboratory. The stream where S. suzanae sp. nov. was collected is similar to that described to S. bare sp. nov.

Figures

FIGURE 25. Stenochironomus manauara sp. nov., adult male. A, hypopygium dorsal view. B, hypopygium with tergite IX removed, left dorsal view, right ventral view. C, anal point, in lateral aspect.

FIGURE 29. Stenochironomus suzanae sp. nov., adult male. A, head. B, thorax. C, hypopygium. D, wing.

FIGURE 30. Stenochironomus suzanae sp. nov., adult male. A, hypopygium in dorsal view. B, hypopygium with tergite IX removed, left dorsal view, right ventral view.