Not endemic after all: Imparipecten Freeman, 1961 (Diptera: Chironomidae) described from the Neotropical Region Author Fusari, Lívia Maria Author Dantas, Galileu P. S. Author Hamada, Neusa Author Andrade-Souza, Vanderly Author Lima, Kátia M. Author Silva, Janisete G. text Zootaxa 2018 2018-12-19 4532 3 396 406 journal article 27742 10.11646/zootaxa.4532.3.5 d3512743-db5f-4bba-b954-e60da16b6c4d 1175-5326 2615463 E70FD90E-32C7-4A31-B61B-4A45D256346D Imparipecten sychnacanthus Fusari, Dantas and Hamada , sp. n. ( Figs. 2–4 ) Type material. HOLOTYPE : 1 male , BRAZIL , Amazonas , Itacoatiara , Mil Madeireira Itacoatiara Ltda , 3°07’30”S 58°26’52”W , 30.iv.2009 , immersed wood, leg. Escarpinati, S. C. , Dantas, G. P ., (voucher) ( INPA ) . PARATYPES : 5 male same data of holotype except 10–22.iv.2009 ; 3 larvae ( 2 larvae are vouchers), same data of holotype except 18.iv.2009 ( INPA ) ; 2 male with pupal exuviae, Amazonas , Barcelos , Rio Ataiana , affluent of Rio Negro , 00°58’56”S 62°54’13”W , 10.viii.2009 , immersed wood, leg. Hamada, N. , Pes, A. M. O . ( INPA ) . Etymology. The specific name is from Greek sychn (many) and the suffix - acanth Latinized from the Greek akantha (thorn or spine), referring to many spines on the anal spur of pupae. Diagnostic characters. Imparipecten sychnacanthus sp. n. differs from Imparipecten pictipes by the combination of the following characters. Male: femur brownish; tibia dark brown with frontal area of the distal region white; tarsomere 1 white, tarsomeres 2–5 dark-brown. Pupa: arrangement of shagreen in TV with rectangular area of spinules but absent in vertical median strip and in TVI with rectangular area of spinules but absent in the small median region; anal spur with 7 teeth, the apical one longer than the other six. Larva: arrangement of mental teeth, with the first lateral tooth shortest, second and third lateral teeth fused and large, fourth to seventh on an even slope decreasing in size laterally. Male (n = 8) . Total length 5.57–6.32 mm . Wing length 2.83–2.89 mm . Total length/wing length 2.0–2.2. Wing length/length of profemur 1.6–1.7. Coloration. Head light-brown. Thorax dark-brown; halteres light-brown; wing without macula, two dark markings in cells r 4+5 , one in m 1+2 , in m 3+4 and cu. Foreleg with femur brownish, tibia dark brown with frontal area of the distal region white; tarsomere 1 white, tarsomeres 2–5 dark-brown; mid and hind legs with femur and tibia brownish, tarsomere 1 anterior 2/3 light-yellow and brownish apically, tarsomeres 2–5 brownish. Abdominal segments brown. Head . Eyes bare, frontal tubercles absent. AR 2.5–2.8, antenna with apical flagellomere 1204–1316 µm long, basal 12 flagellomeres 457–484 µm long. Temporal setae 22–29. Clypeus with 44–55 setae. Palpomere lengths ( 1– 5 in µm): 56–87; 89–94; 276–303; 256–297; 403–439. Wing . VR 1.07–1.10. Brachiolum with 3 setae. R with 11–13 setae; R 1 with 8–12 setae; R 4+5 with 17–28 setae. Squama with 5 setae. Anal lobe weak. Thorax . Scutum without tubercle. Dorsocentrals 11–14; acrostichals 8–10; prealars 5–6. Scutellum with 14–17 setae biserial. TABLE 1. List of taxa and GenBank accessions from species included in the analysis.

Species/specimens	28S	CAD1	CAD4	COI
Imparipecten sychnacanthus sp. n. (larva)	MH131689	MH602425	MH602428	MH602425
I. sychnacanthus sp. n. (larva)	MH131690	MH602426	MH602429	MH602426
I. sychnacanthus sp. n. (male)	MH131691	MH602427	MH602430	MH602427
Axarus sp.	HQ440713	HQ440246	HQ440422	HQ440877
Chironomus sp.	HQ440719	HQ440256	HQ440428	HQ440883
Cryptochironomus sp.	HQ440729	HQ440266	HQ440438	HQ440893
Cryptotendipes sp.	HQ440730	HQ440267	HQ440439	HQ440894
Dicrotendipes peringue	HQ440732	HQ440270	HQ440440	HQ440896
Dicrotendipes sp.1	HQ440733	HQ440271	HQ440441	HQ440897
Dicrotendipes sp.3	HQ440734	HQ440272	HQ440442	HQ440898
Glyptotendipes sp.	HQ440752	HQ440286	HQ440454	HQ440914
Harnischia sp.	HQ440753	HQ440287	HQ440455	HQ440915
Imparipecten sp. 2	HQ440760	HQ440295	HQ440462	HQ440922
Imparipecten pictipes	HQ440759	HQ440294	HQ440461	HQ440921
Kiefferulus barbatitarsis	HQ440762	HQ440297	-	HQ440923
Kiefferulus calligaster	HQ440763	HQ440298	HQ440464	HQ440924
Nilothauma sp.	HQ440782	HQ440316	HQ440481	HQ440945
Pagastiella sp.	HQ440788	HQ440321	-	HQ440951
Parachironomus sp. 1	HQ440791	HQ440323	HQ440486	HQ440954
Parachironomus sp. 2	HQ440792	HQ440324	HQ440487	HQ440955
Paracladopelma sp.	HQ440793	HQ440325	HQ440488	HQ440956
Polypedilum nubiferum	HQ440812	HQ440345	HQ440505	HQ440975
Polypedilum prasiogaster	GU356717	HQ440348	GU356689	GU356707
Polypedilum vanderplankei	HQ440816	HQ440350	HQ440509	HQ440976
Xylochironomus kakadu	HQ440863	HQ440403	HQ440551	HQ441025

Legs . Scale of fore tibia rounded. Spur of mid tibia 42–46 µm long. Spur of hind tibia 46–52 µm long. Length (in µm) and proportion of legs as in Table 2 . Hypopygium ( Fig. 2 A–D). Tergite IX with 23–28 median setae. Anal tergite band well developed. Anal point 82–101 µm long. Phallapodeme 99–124 µm long, transverse sternapodeme 71–89 µm long. Gonocoxite 234–250 µm long. Total length of superior volsella ( Fig. 2D ) 111–129 µm long. Inferior volsella ( Fig. 2C ) 160–198 µm long. Gonostylus 187–219 µm long. HR 1.07–1.34; HV 2.63–3.01. FIGURE 2 . Imparipecten sychnacanthus sp. n. , male. (A) hypopygium, dorsal view. (B) hypopygium with tergite IX and anal point removed, dorsal view left, ventral view right. (C) Detail of superior volsella. (D) Detail of inferior volsella. FIGURE 3 . Imparipecten sychnacanthus sp. n. , pupa. (A) Frontal apotome. (B) Abdomen. (C) Anal spurs. FIGURE 4 . Imparipecten sychnacanthus sp. n. , larva. (A) Dorsal sclerites. (B) Antenna. (C) Mandible. (D) Mentum and ventromental plates. TABLE 2. Lengths (in µm) and proportions of legs of Imparipecten sychnacanthus sp. n. , male (n = 1–8).

Fe	Ti	ta1	ta2	ta3	ta4	ta5	LR	BV	SV
P1	1627–1786	1673–1835	2002–2099	1134–1269	940–1019	886–981	408–446	1.09–1.25	1.54–1.66	1.58–1.81
P2	1448–1542	1392–1543	692–750	454–512	327–331	130–169	87–116	0.49–0.50	3.33–3.52	4.00–4.11
P3	1636–1722	1801–1914	1084–1145	711–767	506–604	298–325	126–135	0.58–0.60	2.62–2.76	3.17–3.21

Pupa (n = 2) Medium-sized, up to 7mm long. Coloration . Thorax, cephalic area and anterior abdominal segments brown, remainder segments pale-brown, apophyses weakly darkened. Cephalothorax . Frontal setae present, cephalic tubercles absent. Frontal apotome wrinkled, without frontal warts ( Fig. 3A ). Thoracic horn with two thick branches apically plumose; basal ring well developed, oval. Median suture moderately rugose, with some linearly arranged spines close to suture. Prealar tubercle absent. Two setae antepronotals, 1 dorsal 50 µm long and 1 lateral 14 µm long. Two precorneals setae. Four dorsocentrals: Dc 1 31– 32 , Dc 2 28–38 , Dc 3 26–36 , Dc4 31 µm long. Distance between Dc1 abd Dc 2 15–20 µm, between Dc2 and Dc3 171–200 µm, and Dc3 and Dc4 of 18–29 µm. Abdomen ( Fig. 3B ). Tergite I bare, TII with subquadrate area of spinules, broader anteriorly but otherwise differentiated only by slightly stronger spinules in the anterior sector, TIII and TIV with rectangular area of spinules, TV with rectangular area of spinules but absent in vertical median strip, TVI with rectangular area of spinules but absent in the small median region, TVII–VIII with small antero-lateral spinule area. Anal segment bare. Tergite II with a continuous row of hooks, with 50% of the tergite width. Conjunctive III/IV and IV/V with a wide band of spine. Sternites II–VIII with fine spinules, more retricted to anterior area on posterior sternites. Pleura bare except spinose on posterolateral corner of V and VI. Pedes spurii A on IV–VI; pedes spurii B well developed on segment II. Anal spurs 91–99 µm long, formed by 7 teeth, one apical longer and six smaller ( Fig. 3C ). Setation . Segment I with 2D, 1V and without L setae; II–VII with 5D, 3V ; 3L on II–IV, V–VII with 4 taeniate setae and VIII with 5 taeniate setae; VIII with 1D, 2V setae. All tergites with a pair of oral setae. Anal lobe with uniserial fringe of 50+ taeniate setae, with narrow taeniate dorsal seta displaced more posteriorly than usual. Genital sac of male not reaching apex of anal lobes, female genital sac shorter than anal lobes. Larva (n = 3) Head . Frontal apotome reticulate, anterior half parallel-sided, without frontal pit; 2 median and 3 lateral labral sclerites ( Fig. 4A ). Pecten epipharyngis with three broad scales, each with 6–8 apically rounded teeth. Premandible with 2 teeth and a strong brush. Antenna 154–169 µm long, with 6 segments ( Fig. 4B ), 88–103, 20–22, 15–17, 13, 11–12 and 4–5 µm long; AR = 1.33–1.57. Accessory blade short, Lauterborn organs alternately on apices of segments 2 and 3. Mandible ( Fig. 4C ) 298–300 µm long, with dark apex and 3 inner teeth, dorsal tooth present, internal seta present, subdentalis seta inserted on ventral surface, somewhat sickle-shaped and extending to innermost mandibular teeth. Mentum 191 µm wide, with a median bifid tooth and seven pairs of lateral teeth ( Fig. 4D ). Median tooth about 0.5 shorter than third tooth. First lateral tooth smallest, second and third laterals teeth fused and large; fourth to seventh on an even slope and decreasing in size laterally, teeth dark. Ventromental plates 219–220 µm wide, medially separated by distance between the fourth lateral teeth. Setae submenti simple. Distribution. The species is known from the state of Amazonas , Brazil . Comments. Freeman (1961) and Cranston & Hardwick (1996) emphasize the importance of the shape of the mid- and hind tibial combs as well as the “close approximation of wing vein R2+3 to R1” for the diagnosis of the genus Imparipecten . The shape of the mid- and hind tibial combs in the males analyzed seem close to those of Cranston & Hardwick (1996) , but we cannot establish how close the R2+3 and R1 veins are since there is no available measure of this. We also were unable to analyze specimens of I. pictipes morphologically.