A New Species of Leptometopa Becker , 1903 ( Diptera , Milichiidae ) and an Identification Key for the Neotropical Species of the Genus

The Milichiidae family includes species of small acalyptratae flies distributed into 19 genera, over all biogeographic regions. The genus Leptometopa Becker, 1903, positioned among the Madizinae, is distributed worldwide. The genus is composed of 19 species, of which three are recorded for the Neotropical region: L. halteralis (Coquillett, 1900), L. latipes (Meigen, 1830) and L. niveipennis (Strobl, 1898). Studying material collected in a cave of Amazonas State, Brazil, the authors found a new species of Leptometopa which is described and illustrated herein. The new species L. veracildae n. sp. represents the first record of the genus in South America. An identification key for all Neotropical species is also presented.

discussed the morphology and character transformation, and presented a phylogenetic hypothesis for the family.
Leptometopa Becker, 1903 is a discrete genus of flies with nineteen species placed among the subfamily Madizinae.The genus can be easily separated from other genera by the ventral prolongation of the lunule, which almost reaches the epistoma, a subtriangular dorsal extension of the lower facial margin, and a sometimes enlarged hind tibia.Adults are found in many kinds of habitats such as in caves and nests of birds, on faeces, flowers, and fungus.Some are kleptoparasites of spiders and predatory insects (Brake 2000).Currently three species are recorded from the Neotropical Region: L. halteralis (Coquillett, 1900), L. latipes (Meigen, 1830) and L. niveipennis (Strobl, 1898).

INtRoDuCtIoN
The Milichiidae (Diptera, Schizophora) are composed of almost 250 species of small acalyptratae flies described in 19 genera distributed over all biogeographic regions.The family is divided into three subfamilies: Madizinae, Milichiinae, and Phyllomyzinae (Brake 2000).Melander (1913) presented a key for the genera, but with several genera not belonging to the Milichiidae.Hennig (1937) wrote one of the most important taxonomic studies on the Milichiidae, with descriptions of all Palaearctic species.Hennig also presented identification keys to the species and a discussion about phylogeny and geographical distribution of the family.Griffiths (1972) presented a detailed study of male terminalia of Milichiidae.

MAtERIAL AND MEthoDS
All studied material belongs to the collection of Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, AM, Brazil.Paratypes were also deposited at Departamento de Zoologia da Universidade Federal do Paraná (DZUP), Curitiba, PR, Brazil; Museu de Zoologia da Universidade de São Paulo (MZUSP), São Paulo, SP, Brazil and Museu Nacional, Universidade Federal do Rio de Janeiro (MNRJ), Rio de Janeiro, RJ, Brazil.
For terminalia analysis the abdomen was removed and placed in a 10% solution of KOH for 60-80 minutes without heating.The abdomen was then washed in distilled water, dehydrated in an increasing ethanol series (30%, 50%, 70% and 95%) and cleared in lactophenol.After studying the terminalia were stored in glycerol in a plastic vial fixed to the insect pin.
The analysis and illustrations were made using stereomicroscope Zeiss Stemi SV 6 and microscope Zeiss Axioskope 40, both equipped with a camera lucida.

DISCuSSIoN
Many of the Milichiidae genera have a world wide distribution, and some of the scavenger species have been widely disseminated in commerce (Sabrosky, 1987).The 19 species of Leptometopa are distributed over all biogeographic regions.This is the first record of the genus from South America.
Leptometopa veracildae n. sp.exhibits a silvery microtomentose postfrons and mesonotum.As proposed by Brake (2000) the presence of silvery microtomentum could be an adaptation for swarming behavior, so that males swarming in the sunlight can be seen from a long distance.
If this behavior is valid to L. veracildae n. sp.their adults should leave the caves to swarm as they were collected about 300 meters from the entrance in an aphotic zone.