Description of Muscotabanus gen. nov. and Muscotabanus rafaeli sp. nov. (Diptera: Tabanidae: Diachlorini) from Amazon Basin, Brazil

A new genus of Tabanidae mimetic of flies is described: Muscotabanus new genus, Muscotabanus rafaeli new species, based on 12 females collected in the state of Amazonas, Brazil. It is presented a discussion for separating the new genus from Diachlorini species which resemblance with sarcophagids flies. It is characterised by striped thorax, banded abdomen, long slender palpus subequal antenna length, labella predominantly membranous, except for a narrow sclerotised plate, basicosta bare, wing hyaline and stigma brown.

The tabanids are stout-bodied flies, commonly known as horse flies or deer flies.The family is allocated in suborder Brachycera Macquart, clade Orthorrhapha Brauer, and has 4,434 species distributed in 156 genera (Pape et al. 2011).Among tabanids, the Diachlorini has the highest richness in the Neotropical region, with 594 species of a total 1,205 valid species (Henriques et al. 2012).Some species, such as Eutabanus Kröber, Myiotabanus Lutz, Philipotabanus Fairchild and Stypommisa Enderlein, have specimens mimetic of Muscomorpha dipterous like Sarcophagidae and Muscidae.
Analysing the entomological collection of National Institute for Amazonian Research (INPA), it was found unidentified female specimens of Diachlorini rather similar to muscoids.They are being described as a new genus and species below.

MATERIALS AND METHODS
The material studied is deposited in the Collections of the INPA [Manaus, state of Amazonas (AM)], Museu Paraense Emílio Goeldi (MPEG) (Belém) and Museum of Zoology of the University of São Paulo (MZUSP) (São Paulo).Specimens were examined and digitally photographed through a stereomicroscope LEICA M205 C coupled with a LEICA DFC 295 camera and software for digital image processing Leica Application Suite LAS V3.6.The terminalia was drawn using a camera lucida coupled to optic microscope LEICA DM 1000.
Terminology follows Burger (2009) and Cumming and Wood (2009).Dissection follows Cumming (1992) protocol.Head: eyes red-brownish in life.Ocellar tubercle vestigial, ocelli absent, vertex black with small sclerotised area, black haired.Frons (Fig. 3) slightly convergent basally, white-brownish pruinose, yellowish dorsally, with black and white hairs; frontal index 5.0; divergence index 1.4; frontal callus blackish, clavate (ridge-like), narrower than frons (not touching the lower inner margin of the compound eyes) and extending until superior half of frons.Subcallus white pruinose.Clypeus and gena with white pruinescence and hairs.Palpus brown, white pruinescent, slender and elongated; first segment long and white hairs; second segment mainly white haired and some black at distal third.Theca brown, membranous; labella brown, mostly membranous (Fig. 5).Antenna (Fig. 4): scape and pedicel brown-orange with black pi-losity; basal plate brown with a dorsal raised projection, stylus brown to black with four annuli longer than basal plate length.

Muscotabanus
Thorax: scutum dorsally (Fig. 1) black pruinescent, covered with black and white hairs, except for two white paramedian longitudinal stripes and laterally from postpronotal lobe to postalar callus whitish and predominantly white haired, with few black hairs.Notopleural lobe (lateral view), whitish with many black hairs.Scutellum (dorsal view), bicoloured, anterior half black pruinescent and black haired, posterior margin white pruinescent black and white haired.Pleuron white pruinescent and pilosity, except for anepisternum black haired ventrally.Legs slender, coxae concolorous with pleuron.Trochanters, femora, tibiae and tarsi dark brown, black haired.Wing hyaline with dark brown veins; pterostigma brown; R 4 +5 with a small appendix at fork of (only in right wing in holotype).
Br. Guiana, but smaller, with narrower and slightly different frons etc.I have another species from Rio de Janeiro which seems obviously related, but which lacks the thoracic stripes of your species (INPA).All three specimens are quite similar and quite different from most Stenotabanus.In some ways they are like Philipotabanus, but I believe represent a distinct genus of unknown affinity.None are similar to Myiotabanus, which has a peculiar frons, very short stout palpi and very long proboscis".
St. tantulas refers to Stypommisa tantula (Hine, 1920) treated as invalid species by Fairchild and Wilkerson (1986) and removed from Catalog of the Tabanidae of Fairchild and Burger (1994) without any justification, but it was again included in Stypommisa by Coscarón and Papavero (2009).In 1996 we sent two female specimens to Dr JE Chainey (The Natural History Museum, London), who at the time was making a revision of South American Stenotabanus.He very helpfully identified the material as: "Philipotabanus (Mimotabanus) sp.near porteri" and "Stypommisa sp." respectively.He did not included in Stenotabanus, demonstrating the degree of uncertainty in identifying the genus of this taxon.Following Fairchild's (1969) genera key, Muscotabanus gen.nov.run to couplet 19 (p.232) of Catachlorops Lutz.It clearly does not belong to this genus.Similarities and differences with other genera in appearance are presented below (Table ).Labella predominantly sclerotised, long-spined antenna, pictured wings.
Pictured wings below stigma, basicosta with setae, vestiges of ocelli present.
Eyes with at least two transverse bands in life, callus not ridge-like generally as wide as frons.
it was used Fairchild (1969) for characters presented here.