T wo new n eoTropical c hironominae genera (D ipTera : c hironomiDae )

Claudiotendipes n. gen. and Sigmoitendipes n. gen. are described and figured based on adults, pu - pae and larvae. Two species are included in Claudiotendipes : the type species, C. froehlichi n. sp. from Bahia, Rio de Janeiro, São Paulo and Santa Catarina States in Brazil; and C. epleri n. sp. from Costa Rica. Five species are included in Sigmoitendipes , all from Brazil: the type species, S. susanae n. sp. from São Paulo, Mato Grosso, Amazonas and Pará States; S. fittkaui n. sp. from Mato Grosso and Pará; S. reissi n. sp. from São Paulo; and S. oliveirai n. sp. and S. spiesi n. sp., both from Mato Grosso. A cladistic analysis grouped the two new genera with Beardius , Oukuriella and Endotribelos . Keys to the males of the two new genera are presented.


Introduction
The subfamily Chironominae comprises approximately 50% of the chironomid species described from the Neotropical region, which is more than twice the share of any other subfamily (e.g.Spies and Reiss 1996: table 1).In the fauna of Brazil, the largest country in the region, the proportion increases to about 60% (335 of 566 scientifically named species, Pinho 2016), whereas the second largest subfamily stands at less than 25% (134 species in Orthocladiinae).Chironominae larvae are found in a wide range of aquatic and semiaquatic habitats, but are relatively more abundant in standing and slow-flowing lowland waters than at lotic sites in mountainous areas.
During the first half of the 1960's, the late E. J. Fittkau made extensive collections in various parts of the Amazon region; this vast amount of chironomid material is now housed in the Zoologische Staatssammlung in Munich, Germany.Fittkau (2001) wrote: "the numbers of 'new species' and 'new genera' increased with each new light catch.
I stopped this work when we had reached the number of 500 new species and 50 new genera, as well as a number of familiar genera".Fittkau (1971) suggested that at least 1000 species of Chironomidae live in the Amazon.Since then, many new species and several new genera have been described.In Brazil alone, for example, 32 Chironominae genera with more than 330 species are recognized (Pinho 2016).Even so, much of Fittkau's material still awaits analysis and publication, and the knowledge of Brazilian chironomids remains fragmentary.
Below we describe a new genus, Sigmoitendipes, based partly on material collected by Fittkau in the Amazon, and partly on more recent material gathered from several other Brazilian regions.The description is based on males, pupae and larvae, and five new species are recognized.Claudiotendipes n. gen. is described from material collected in the Brazilian Atlantic Forest (Mata Atlântica) as well as Costa Rica.Keys to the males of both genera are provided, and their relations among the Chironominae are evaluated based on a cladistic analysis.

Specimens, identification and terminology
Except for the material obtained on loan, specimens examined were preserved in alcohol and later mounted on slides in Canada balsam or Euparal following the procedure outlined by Saether (1969); some slide-mounted specimens borrowed from Zoologische Staatssammlung München (ZSM) were not cleared in KOH.Since there are no identification keys which cover southern hemisphere chironomid fauna, identification of material was completed using keys for Central American and Holarctic genera (Pinder and Reiss 1986, Cranston et al. 1989, Spies et al. 2009, Epler et al. 2013).Comparison to descriptions of austral Chironominae genera not included in these keys, such as Tapajos Trivinho-Strixino, Silva et Oliveira (from Trivinho-Strixino et al. 2013), Nilodosis Kieffer, Imparipecten Freeman (from Cranston and Hardwick 1996), Conochironomus Freeman (from Cranston and Hare 1995) and Xylochironomus Cranston (from Cranston 2006) were also conducted.Diagnoses of both new genera were then prepared considering differential characters from all of these sources.The descriptive terminology follows Saether (1980), with some additions and modifications from Epler et al. (2013).Measurement results are given as ranges, followed by the mean when four or more specimens were measured, followed by the number of specimens measured (n) in parenthesis.

Type material
The type materials are housed in the following museums (listed in alphabetical order): INPA -Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil.

Phylogenetics
To assess the phylogenetic positions of the new genera we used a matrix with 119 characters in 71 taxa (Appendix 1) that is based on the data in Cranston (2003Cranston ( , 2006) ) (matrix kindly made available by request) plus data on Beardius Reiss et Sublette (from Pinho et al. 2013), Oukuriella Epler (from Fusari et al. 2013), Endotribelos Grodhaus (from Grodhaus 1987, Roque andTrivinho-Strixino 2008), Claudiotendipes n. gen.and Sigmoitendipes n. gen.(from present study).The character states for Nilothauma Kieffer were revised according to Mendes and Andersen (2008).'Gen.A' refers to an undescribed Afrotropical genus with wood mining larvae (Cranston 2006).
The matrix was edited in Mesquite (Maddison and Maddison 2009), the analyses were performed in TNT software (Goloboff et al. 2008b), and the character distribution was visualized in Winclada (Nixon 1999(Nixon -2002)).All characters were treated as unordered under the implied weighting searches (Goloboff 1993).Heuristic tree searches were run with the tree bisection and reconnection (TBR) branch swapping algorithm (1000 replications, random seed = 0).A TNT script (propk.run,written by Salvador Arias) calculated the appropriate value for the k constant (for details, see Goloboff et al. 2008a); it returned a value of k = 15.263673 for the data set selected for the analysis.

Systematics
Chironominae relationships have been assessed by Saether (1977) using morphological data, proposing the tribes Tanytarsini, Pseudochironomini and Chironomini (Fig. 1A).Cranston et al. (2012) analysed molecular data from four genes using mixed-model Bayesian and maximum likelihood inference methods, and suggested Chironomini is paraphyletic because it includes Tanytarsini and Pseudochironomini (Fig. 1B).Also, Shangomyia Saether et Wang, sister to all remaining Chironominae, could deserve a tribe or subfamily rank togeth-er with Xiaomyia Saether et Wang.The cladistic analyses performed here resulted in a cladogram (Fig. 2) where Tanytarsini and Chironomini are sister tribes.Shangomyia Saether et Wang grouped with Nandeva Wiedenbrug et Fittkau within Stenochironomus complex as found in Cranston (2003) from a previous version of the present data matrix.Since information about Nandeva Wiedenbrug et Fittkau larva is unavailable and morphology of pupae and adults of Shangomyia Saether et Wang are uninformative and very divergent, the inclusion of these genera in the Stenochironomus complex is very doubtful.
The clade (Sigmoitendipes n. gen.(Endotribelos (Claudiotendipes n. gen.(Beardius, Oukuriella)))) is recognized by the combination of some homoplastic synapomorphies in the pupa (absence of scutal tubercle, presence of pedes spurii B and abdominal segment VIII posterolateral spur with one more or less dominant tooth) and adult (mid leg without sensilla chaetica).
As 16 out of 40 of the larval characters could not be extracted from the single larval specimen of  Sigmoitendipes studied, this relationship hypothesis should be viewed as tentative and will likely improve as more larval material becomes available and more Chironomini genera are included in the data matrix.
Etymology: Named in honor of Professor Dr. Claudio G. Froehlich for his many important contributions to aquatic entomology and for initiating, with all his kindness and knowledge, the formation of many Brazilian research groups in ecology and systematics of aquatic insects.The suffix -tendipes, is a common ending among Chironominae genera.For the purposes of nomenclature, the gender of the genus name is masculine.

Diagnostic characters:
The males can be separated from all other Chironomini by the combination of an antenna with 13 segments, antennal ratio 0.3-1.1;squama bare; wings lacking markings; fore tibia with weakly developed, shallow scale without spur; mid-and hind tibiae with short, fused combs, with single spur; anal tergite bands separate; setae on tergite IX restricted to posterior margin; anal point long, parallel-sided to weakly spatulate; superior volsella digitiform without basomedial group of setae; median volsella reduced to single setae; and inferior volsella apically forked.
The pupa can be separated from all other Chironomini except Paratendipes by the combination of a thoracic horn with few branches; cephalic tubercles and frontal setae present; tergites II-VI with anterior bands of weak shagreen; large pedes spurii B on segment II; segment II with 2-3 nontaeniate L setae, segments III-IV each with 3 nontaeniate L setae; and anal lobe with fringe and dorsal seta.It can be separated from Paratendipes by the bare conjunctive III/IV.The larva can be separated from all other Chironomini except Omisus and Paratendipes by the combination of a plumose S I; mentum with four pale median teeth, the inner pair of which are smaller and shorter; and antenna with 6 segments and alternate Lauterborn organs.It can be separated readily from Omisus and Paratendipes by the presence of 3 inner teeth on the mandible; the shape of the ventromental plates; and the simple pecten epipharyngis with about 12 teeth.

Generic description
Male.Small to medium sized species, with wing length 1.0-2.0mm.
Coloration.Whitish to pale yellowish, wing translucent without dark markings.
Wing. .Wing membrane bare, with fine punctation.Anal lobe absent to weakly developed.Costa not extended, reaching wing tip; R 2+3 ending close to apex of R 1 ; FCu distal to RM. Brachiolum, R, R 1 and R 4+5 with setae, remaining veins bare.Squama bare.
Hypopygium.Anal tergite bands separate, ending slightly above or reaching base of anal point.Tergite IX in dorsal view (Figs 3F, 6F) with posterior margin subtriangular, with few marginal setae to each side of anal point only.Anal point parallelsided to weakly spatulate, one-third to one-fourth the length of gonostylus, with microtrichia at base only.Laterosternite IX without or at most with three setae.Transverse sternapodeme well developed, nearly straight, with slightly higher lateral corners.Phallapodeme narrow.Superior volsella without setose base, curved to nearly straight, tapering towards apex, without microtrichia, with two dorsal-lateral and two distal-medial setae.Me-dian volsella possibly represented by one to two setae on single, small protuberance.Inferior volsella apically foot-shaped, with microtrichia, with 5-7 simple setae on main branch and 3-5 simple or apically split setae on side branch.Gonostylus well developed, with simple setae along inner margin, and with or without apical field of elongate trichia along inner margin.HR 0.85-1.13.

Female. Unknown.
Pupa and larva.See description under C. froehlichi.

Diagnostic characters:
See key.

Distribution and ecology
This species is apparently widely distributed along the Atlantic rainforest in Brazil, ranging from 220 m to over 1450 m altitude between latitudes 11° and 28°S.The larva was collected in leaf debris in a first order stream which flows through a forested area in Serra Bonita, Bahia State.Similar conditions occur at other localities where adults were collected in light or Malaise traps.
Etymology: Named after Dr. John H. Epler for his many contributions to the taxonomy and ecology of chironomids from the New World.
Diagnostic characters: See key.

Distribution and ecology
This species is only known from Guanacaste Conservation Area in northwestern Costa Rica where it was collected in a Malaise trap at a small, shallow river with stony bottom at 1000 m altitude.

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Type species: Sigmoitendipes susanae n. sp.

Etymology:
The specific epithet refers to the shape of the superior volsella resembling the lower-case Greek letter sigma.The suffix -tendipes is a common ending among Chironominae genera.For the purposes of nomenclature, the gender of the genus name is masculine.

Diagnostic characters
The males can be separated from all other Chironomini by the combination of an antenna with 13 segments, antennal ratio about 2.0; squama with 5-11 setae; wings lacking markings; fore tibia with well-developed, bearded scale, comb of mid tibia with one spur, comb of hind tibia with two spurs; anal tergite bands weak, adjacent to anterior tergite margin, in some species with short median longitudinal extension; setae on tergite IX restricted to posterior margin and/or base of anal point; anal point strong, spatulate; superior volsella complex, composed of a median or ventral, rounded or subrectangular part densely covered with microtrichia and carrying a few setae in some species, and of a dorsal to apical part with several strong setae and in some species with sparse microtrichia, dorsal part with apex more or less hooked; inferior volsella near mid-length with bluntly triangular dorsal lobe.
The pupa shares with those of some other Chironomini the combination of long, robust frontal setae; well-developed, conical cephalic tubercles; strongly plumose thoracic horns; anterior, transverse bands of shagreen on tergites II-VI; robust, longitudinal anal combs; and no dorsal setae on the anal lobes.It can be separated by having only one median antepronotal seta, and 5 LS setae on segment VIII.
The larva has a six-segmented antenna with a single well-developed Lauterborn organ on the sec- ond segment; the mandible has one dorsal, one apical and four inner teeth, with the seta subdentalis long, slender and straight; the mentum with 8 pairs of equally sclerotized teeth, the first lateral teeth larger than the median pair, the second lateral teeth smaller than both their immediate neighbours, and the further lateral teeth decreasing progressively to a minute seventh tooth; and the ventromental plates slightly wider than the mentum, and separated by the width of 4-5 mental teeth.

Distribution and ecology
Found in São Paulo, Mato Grosso, Amazonas and Pará states.Fittkau collected the species using Brundin nets in shallow Amazonian forest streams of first, second or third order in evergreen tropical inundation forest.The streams were 1-2 m wide, shallow, flowing, and with bottoms of sand and

Distribution and ecology
Collected in Mato Grosso and Pará States.

Distribution and ecology
Only known from Mato Grosso, where it was collected in a light trap at a fast flowing river with mostly rocky bottom sediments.Thorax.Antepronotum without setae.Dorsocentrals 6-7, acrostichals apparently 6, prealars 3-5.Scutellum with 7-9 setae in single row.

Distribution and ecology
Only known from Mato Grosso State, where it was collected in a light trap at a small, rather slow flowing stream with mostly fine bottom sediments.

Figure 2 .
Figure 2. Cladogram obtained from data matrix performing search using implied weighting of characters (k= 15.263673).

Figure 3 .
Figure 3. Claudiotendipes froehlichi n. sp., male.A, Head.B, Tentorium, stipes and cibarial pump.C, Thorax.D, Apex of fore tibia.E, Wing.F, Hypopygium, dorsal view.G, Hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.
1 31 μm long, Dc 2 35 μm long, Dc 3 33 μm long, Dc 4 21 μm long; Dc 1 1 μm in front of Dc 2 , Dc 2 117 μm in front of Dc 3 , Dc 3 29 μm in front of Dc 4 .Wing sheath 1.07 mm long, without nose or pearl row.Abdomen (Fig.4D).Tergites I and IX bare; tergites II-IV with median field of fine shagreen and anterior band of slightly stronger shagreen, tergite IV with median field barely separated from anterior band; tergite V with continuous median, fine shagreen; tergite VI with widely separated anterior and posterior transverse fields of fine shagreen; tergites VII-VIII with anterolateral patches of fine shagreen.Sternites bare.Hook row on tergite II with 26 caudal hooklets in single, 148 μm wide row.Conjunctive IV/V with about 120 spinules in 4-5 rows.Pedes spurii B well developed posteriorly on segment II; pedes spurii A lacking.Segment VIII caudolateral spur (Fig.4E) 160 μm long, with 3 strong apical teeth.Abdominal setation.Segment I without L setae, segment II with 2-3 non-taeniate L setae, segments III-IV each with 3 non-taeniate L setae, segments V-VIII each with 4 taeniate LS setae.Dorsal and oral ('O') setae apparently present on segments II-VII, segments I and VIII apparently each with single pair of dorsal setae.Anal lobe.Fringe with 18 taeniae.Male genital sac

Figure 6 .
Figure 6.Claudiotendipes epleri n. sp., male.A, Head.B, Tentorium, stipes and cibarial pump.C, Thorax.D, Apex of fore tibia.E, Wing.F, Hypopygium, dorsal view.G, Hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.

Figure 11 .
Figure 11.Sigmoitendipes fittkaui n. sp., male.A, Wing.B, Hypopygium, dorsal view.C, Hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.D, Superior volsella.

Figure 12 .
Figure 12.Sigmoitendipes oliveirai n. sp., male.A, Wing (tip missing).B, Hypopygium, dorsal view.C, Hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.D, Superior volsella.

Figure 14 .
Figure 14.Sigmoitendipes spiesi n. sp., male.A, Wing.B, Hypopygium, dorsal view.C, Hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.D, Superior volsella.
Pupa and larva.See description under S. susanae.RemarksLarvae of Sigmoitendipes n. gen.may represent the morphotype "Endotribelos sp.2" (Trivinho-Strixino 2011), with which it appears to share the sixsegmented antenna with well-developed Lauterborn organs on the second segment, the mentum with 16 dark teeth of alternating sizes, and the wide ventromental plates.However, the information available on larvae in Sigmoitendipes n. gen.are insufficient for reliable identification with that morphotype.Moreover, the pupal anal comb with about 30 minute teeth that is visible in a pre-pupa of "Endotribelos sp.2" (S.Trivinho-Strixino, pers.comm.)appears to suggest distinct genera.Etymology:Coloration.Thorax brown, head and abdomen light brown, legs pale brown.Wing translucent.
leaves.During the flood season the water level in the streams rose up to approximately 4 m higher.