A new specie of Stenotabanus ( Stenochlorops ) ( Diptera : Tabanidae ) from Amazonas , Brazil , and a key to the subgenus

D e s c r i p t i o n a n d f i g u r e s a r e g i v e n t o r S t e n o t a b a ­ n u s ( S t e n o c h l o r o p s ) b e q u a e r t i n. s p . f r o m A m a z o n a s , B r a z i l . F i g u r e s a r e i n c l u d e d f o r p a r a d o x u s ( L u t z ) a n d v i t r i p e n n i s ( L u t z ) , a n d a k e y t o t h e s u b g e n u s is p r o ­ v i d e d .


INTRODUCTION
A small, shiny blackish species with hya line wings, bicolored legs and yellow pilose scutellum.
FEMALE: body length, 6.2 mm; wing length 5.4 mm.Eyes bare, pattern (in life) dark with two narrow green transverse loops, these margined with red (fig.1e) .Frons (fig.1a) about 2.7 times as high as basal width, slightly wider at vertex than at base; tubercle on vertex with vestiges of 3 ocelli; basal callus black, shiny, protuberant, as wide as f.-ons, with a shiny median upper ridge (median callus) connected to ocellar tubercle Middle of frons with median area blackish in certain lights, otherwise sparsely whitish pollinose.Subcallus black, shiny.Frontoclypeus and gena black, shiny, with sparse beard blackish.Tentorial pits whitish pollinose.An tenna (fig.1b) thinly pollinose; the scape and pedicel brown, black haired; flagellum brown, basally more or less orange yellow, the style ( 1 ) -Instituto Nacional de Pesquisas cia Amazônia, Manaus.
Abdomen completely black and shiny, sparsely short black-haired, except for longer, sparse white hairs laterally end ventrally on last few segments.Genitalia: tergites VIII, IX, X and cerci as, in fig.2a Charlwood & Rafael (1980), who dissected more than 200 females of this species captured during August to October.This seems to be the period of maximum flight activity for this species in the studied area, end agrees with label data from specimens captured in other years and localities.Stenotabanus (Stencchlcrcps) vitripennis (Lutz) (Figs.3a-b, 4a-d Only the figured structures are here de scribed.These figures complement the original description of Lutz which omits, or does not represent adequately, such structures as are needed for a good characterization of the species. HEAD : Frons (fig.3a) divergent at base, basal callosity protuberant, narrower than frons lateral margins pollinose.Subcallus castaneous, shiny, protuberant.Antennal scape about 1/3 basal width of frons.Palpi (fig.3b) castaneous, with pilosity of the same color, slender, as long as height of frons.Antennae missing.
GENITALIA : Tergites VIII, IX and X with shape, pilosity and pigmentation as represented in fig.4a.The cercus represented in this figure is broken at mid-length.Hypoproct (fig.4b) with a small, distinct, medioapical projection and with fine subapical setae.Eighth sternite and gonapophyses (fig.4c) with base straight and apex bilobed.Genital fork (fig.4d) with medial incision at base; lateral arms relatively well sclerotized, and spinous bristles of the genital comb "distinct, though less so than in the preceding species (S. bequaerti).
Basal portion of spermathecal ducts well sclerotized Two paratypes cf this species (T-280 and T-282) were received for study from Instituto Oswaldo Cruz.These specimens arrived badly damaged in the mail.The associated parts were giued to the insect.However, when this was not possible, parts were mounted on slides and received the same label as the pinned insect.The original description of this species was based on six specimens collected in Ouixada (Ceara State) .
The genitalia are not figured, since the abdomen has been damaged since the time of the original description.This species was described from a single specimen that ap peared altered "in consequnce of the attacks of a destroying insect".Damage included complete lack of the left leg and part of ths right leg of the prothorax, lack of the antenna!flagella, and as mentioned, a mutilated ab domen.Fairchild (1961) encountered a type still more altered "It lacks all but one leg, and one antenna is missing, and the colors are obscured by glue".Presently, this holotype specimen appears still more damaged, due to the damage incurred in the mail systems.The pinned insect possesses only a headland a thorax.On the head, only the p£.lpi, both scapes and the pedicel of only one antenna are present.On the thorax, only the right metathoracic leg and halteres remain.The wings, labella, and some abdominal fragments are mounted on slides, (lam.T-277) .

St. (Stenochlorops)
bequaerti n. sp. is most similar to St. (Stenochlorops) vitripennis (Lutz), described from Ceara.It appears to differ from vitripennis in having wholly trans parent wings, without the darkened extreme base of the wing, or yellowish costal cell shown by Lutz (1913) It also has a black subcallus apparently brown in vitripennis, and the frons is narrower and more convergent at base in the new species.According to Lutz' figure (1913, Est. 12, fig. 11) shiny scale like hairs are 'ess abundant on the scutellum of vitri pennis than on the new species.The unique eye pattern of vitripennis is like that of the new species.Comparison with Lutz' holotype and his description and figure of his Diachlorus paradoxus indicates that it is also similar, but has a much wider frons and different eye pattorn than either vitripennis or bequaerti.Fairchild (1961) discussed the types of both Lutz' species and noted that both differed from a specimen reported by Bequaert as paradoxus from lower Rio Negro, and another which he saw in Instituto Oswaldo Cruz from Rio Japura, Ducke coll.The Rio Negro specimen has been compared and it is the same as the