A new species of predaceous midge in the Patagonian genus Austrosphaeromias with a redescription of A. chilensis (Diptera, Ceratopogonidae)

. A new species of predaceous midge, Austrosphaeromias setosa sp. nov., is described and illustrated from adult males and females collected in the Patagonian-Andean region of Argentina and Chile. Based on examination of the type species of Austrosphaeromias Spinelli, 1997 and recently collected specimens from near the type-locality, the female and previously unknown male of Austrosphaeromias chilensis (Ingram & Macfie, 1931) are also described and illustrated. Descriptions are accompanied by color photographs and illustrations of key features of females and males of both species. We also provide a key to adult females and males of the four species of Austrosphaeromias .

During our study of Patagonian predaceous midges in the genus Palpomyia Meigen (Spinelli et al., 2009), we initially considered the latter two above species as members of this genus because their uncanny resemblance to species of the distincta group.For example, both species possessed greatly swollen fore femur with numerous ventral spines, and females had short, equal-sized claws and small, ovoid subequal-sized spermathecae (GroGan & Wirth, 1979).However, males lacked a mesobasal tubercle on their gonocoxites as well as a broadly triangular apex on their aedeagus, and females lacked a pair of soft setose lobes on the anterolateral margins of sternite 8 and a distal hyaline plate on that structure (Spinelli et al., 2009).In addition, sternite 8 of females of the Palpomyia distincta group features a separate proximal portion with scattered setae, whereas both species in question possessed a closely approximated group of more coarse setae.
We eventually determined that both of these species were members of the genus Austrosphaeromias.Herein we describe and illustrate a new species of Austrosphaeromias as well as the female and previously unknown male of A. chilensis.

MATERIAL AND METHODS
Specimens were collected with Malaise and light traps, or, by sweeping flowers and other vegetation along the margins of rivers, streams and lakes.All specimens were preserved in 70% ethanol and subsequently cleared, dissected and mounted onto microscope slides in Canada balsam for more detailed study.They were examined and measured at 40-400x with a binocular compound microscope and drawings of diagnostic characters were prepared with the aid of an attached camera lucida.Photomicrographs were taken with a digital camera attached to a microscope.
The holotype and paratypes of our new species are deposited in the MLPA, and paratypes as available are deposited in the U. S. National Museum of Natural History, Smithsonian Institution, Washington, D. C. (USNM); the Natural History Museum, London (BMNH); the Canadian National Collection of Insects, Ottawa (CNCI); and the Florida State Collection of Arthropods, Gainesville (FSCA).Terminology of morphological structures follows those in the Manual of Central American Diptera (BroWn et al., 2009).
Diagnosis.Female with legs mostly yellowish or yellowish brown, fore femur greatly swollen, tarsomeres 5 with 2-8 ventral setae and sternite 8 with tuft of 12-16 large coarse setae.Male legs coloration similar to female or with distal 1/3 of femora and basal 1/3 and narrow apex of tibiae brown, gonostylus nearly straight, 0.66 length of gonocoxite, and aedeagus as long as basal breadth.
Austrosphaeromias chilensis is also similar to A. setosa sp.nov.However, the female of the latter species has shorter flagellomeres 9-13, tarsomeres 5 lack stout ventral setae, and the group of setae on the anterior portion of sternite 8 is very peculiar, pear-shaped.Males of A. setosa differ from males of A. chilensis in having a shorter antennal flagellum (antennal ratio 0.57-0.75),moderately long flagellomeres 11-13, an apically curved gonostylus, and a narrower aedeagus with a longer basal arch that extends 0.5 of its total length.
Etymology.The species name is a reference to the conspicuous group of stout setae on sternite 9 of females of this new species.
Taxonomic discussion.Females of this new species are readily distinguished from its congeners by the tarsomeres 5 that lack ventral stout setae and by the conspicuous pear-shaped group of 24-37 stout setae on sternite 8.The male antenna is also very distinctive, with the flagellomeres 11-13 distinctly shorter than in males of A. apricans and A. chilensis, the only other two species with known males.