Neotropical Nilothauma Kieffer, 1921 (Diptera, Chironomidae): Key, eleven new species, re-descriptions, new combination and new records Author Pinho, Luiz Carlos https://orcid.org/0000-0002-9153-9997 Laboratory of Systematics of Diptera, Department of Ecology and Zoology, Federal University of Santa Catarina, Campus Trindade, CEP 88040 - 900, Florianopolis, Brazil luizcarlospinho@gmail.com Author Andersen, Trond Department of Natural History, University Museum of Bergen, University of Bergen, P. O. Box 7800, NO- 5020, Bergen, Norway text ZooKeys 2021 2021-04-22 1033 81 125 http://dx.doi.org/10.3897/zookeys.1033.60686 journal article http://dx.doi.org/10.3897/zookeys.1033.60686 1313-2970-1033-81 BEFB015F4A354987AD10DFEB7D4F91DD 2E6467D3D0025F778A77798A4072BCB5 Nilothauma hamadae sp. nov. Figures 4A, B , 16A Type material. Holotype male, slide-mounted: Brazil, Amazonas, Barcelos, Rio Araca , Foz do Igarape Cuieiras, 00°19'15"N , 63°16'15"W , 35 m a.s.l., 30.vii-01.viii.2009, light trap #11, N. Hamada et al. leg. (UFSC). Etymology. The specific epithet is a noun in the genitive case which honours Neusa Hamada for her great contribution to the knowledge of Amazonian Chironomidae . Figure 4. Nilothauma hamadae sp. nov. adult male A hypopygium, dorsal view B hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right. Diagnostic characters. The male can be distinguished from its congeners by the combination of: tergite IX with single, median setose dorsal lobe, consisting of a low, but wide protuberance with about 25 strong setae; anal point very broad (about half the width of tergite IX) and lanceolate; median volsella separated from superior volsella. Description. Male imago (n = 1). Total length 1.94 mm. Wing length 1.13 mm. Total length/wing length 1.71. Wing length/length of profemur 2.30. Colouration . Head, thorax and abdomen medium brown. Legs light brown. Wing membrane hyaline. Antenna . AR = 0.40. Thirteenth flagellomere 217 µm long. Head . Temporal setae 7 in single row. Clypeus with 15 setae. Tentorium 75 µm long, maximum width 12 µm . Stipes 92 µm long. Palp segment lengths (in µm ): 25, 25, 75, 127, 144. Third palpomere with 2 sensilla clavata subapically, longest 20 µm long. Fifth palpomere/third palpomere 1.93. Thorax . Dorsocentrals 7 in single row, acrostichals 10, prealars 2. Scutellum with 4 setae. Wing . VR = 1.37. Brachiolum with 1 seta, R with 13 setae, R1 with 7 setae, R4+5 with 14 setae, remaining veins bare. Legs . Spur of fore tibia 34 µm long including 12 µm long scale. Mid-tibia with 1 spur, 15 µm long; hind tibia with 2 spurs, 20 and 25 µm long. Combs of mid-tibia 12 µm long, of hind tibia 15 µm long. Width at apex of fore tibia 34 µm , of mid-tibia 34 µm , of hind tibia 39 µm . Lengths and proportions of legs as in Table 3 . Table 3. Lengths (in μm ) and proportions of leg segments in Nilothauma hamadae sp. nov., adult male (n = 1).

-	Fe	Ti	ta1	ta2	ta3	ta4
p1	493	364	-	-	-	-
p2	473	364	217	108	79	49
p3	532	542	315	167	158	99
-	ta5	LR	BV	SV	BR	-
p1	-	-	-	-	-	-
p2	49	0.59	3.62	3.86	3.3	-
p3	69	-	-	-	5.0	-

Hypopygium (Fig. 4A, B ). Tergite IX narrow, tapering to apex, with central rounded lobe bearing 25 simple, strong setae; with 9 simple setae along posterior margin underneath the anal point. Anal point lanceolate, 42 µm long, 27 µm wide. Tergite bands lacking. Laterosternite IX with 1 seta. Phallapodeme 40 µm long; transverse sternapodeme 15 µm long. Gonocoxite 75 µm long. Inferior volsella strongly curved, 37 µm long, 7 µm wide medially, with microtrichia in basal half, with 4 simple setae apically and 1 simple seta subapically. Superior volsella 30 µm long, 4 µm wide at base, covered with microtrichia and fringed at apex. Median volsella 7 µm long, with 2 simple setae, longest 10 µm . Gonostylus 112 µm long, with basal half strongly curved and distal half straight. HR = 0.67. HV = 1.73. Female adult and immatures. Unknown. Distribution (Fig. 16A ). Known from Barcelos (Amazonas State), in the Brazilian Amazon.