New records of Xanthacrona Wulp , 1899 ( Diptera , Ulidiidae ) from Brazil

Xanthacrona Wulp, 1899 has been recorded in several countries of South America, but records in Brazil are few. Here, we record Xanthacrona tuberosa Cresson, 1908, Xanthacrona phyllochaeta Hendel, 1909, and Xanthacrona tripustulata Enderlein, 1921 for the first time from Brazil, and provide new records of Xanthacrona bipustulata Wulp, 1899 from the states Acre, Amazonas, Espírito Santo, Maranhão, Mato Grosso do Sul, Pará, Roraima, and São Paulo.


Introduction
Ulidiidae is a moderately small family of Diptera with 875 species distributed predominantly in the New World (Kameneva and Korneyev 2010).Taxa assigned to this family are mainly saprophagous, although the phytophagous habit is known for a few species, including some of economic importance (Link et al. 1984).
Xanthacrona Wulp, 1899 is a small genus with only 5 described species: Xanthacrona bipustulata Wulp, 1899, Xanthacrona tuberosa Cresson, 1908, Xanthacrona phyllochaeta Hendel, 1909, Xanthacrona tripustulata Enderlein, 1921, and Xanthacrona ypsilon Enderlein, 1921.Species are easily recognized by the bright yellow scutellum with black spots and the pattern of oblique bands on the wings.The genus is widely distributed in the Neotropical Region, occurring from the South of the United States to Northern Argentina (Kameneva and Korneyev 2010).A key to species identification is available in Steyskal (1966).
In Brazil, only 2 species, X. bipustutala and X. ypsilon, have been recorded, both for the state of Rio de Janeiro (Steyskal 1968).Other species have also been recorded in the Neotropical Region.Xanthacrona tuberosa was described by Cresson (1908), based on a single specimen collected in Suriname and later identified by Steyskal (1968) from Trinidad andTobago, French Guiana, andBolivia. Hernández-Ortiz (1986) recorded X. tuberosa from Mexico, whereas Kameneva (2004) and Kameneva et al. (2017) documented it from Costa Rica and Colombia, respectively.Xanthacrona phyllochaeta was described by Hendel (1909) from Paraguay and later recorded from Peru and Bolivia by Steyskal (1968) and from Colombia by Kameneva et al. (2017).Xanthacrona tripustulata was described by Enderlein (1921), based on a single female specimen from Paraguay.
Herein, we report X. phyllochaeta, X. tripustulata, and X. tuberosa for the first time in Brazil.In addition, new records are presented for X. bipustulata from the states Acre, Amazonas, Espírito Santo, Maranhão, Mato Grosso do Sul, Pará, Roraima, and São Paulo.
We used the taxonomic key by Steyskal (1966) for species identifications.Terminology follows Cumming and Wood (2009).Wings of some specimens were detached, cleaned by placing in xylol for a short period of time, and mounted on glass slides containing Euparal.After drying, slides were glued by the margin to a small piece of cardboard and pinned with specimen.Specimens were photographed with a Leica MC170 HD digital camera on a Leica M165C stereomicroscope.The photographs were stacked and combined using Leica Application Suite.
Maps of occurrence were created with Simplemappr (Shorthouse 2010), using geographical coordinates from the specimen labels and bibliography.We used Google Earth ® to locate the approximate collecting site for specimens without geographical coordinates.Square brackets were used to complement label information of the material examined.Asterisks represent new records in the section of geographical distribution.Diagnosis.Thorax and legs yellow to orange yellow; abdomen yellow with narrow dark brown band on posterior margin of tergites (Fig. 1) or entirely dark brown; scutellum swollen, yellow, with a large black spot on each  Diagnosis.Thorax and legs yellow to orange yellow; abdomen pale yellow to brown (Fig. 2); posterior orbital seta and penultimate dorsocentral seta drop-shaped (Figs 2, 7, 8); scutellum slightly swollen, largely yellow, with a small dark spot on each side (Figs 7, 8); wing with costal cell dark brown, with large hyaline median area, cell r 2+3 predominantly hyaline, median transverse band dark brown, straight and separated from costal band by hyaline area in cell r 2+3 at the level of r-m crossvein, vein R 2+3 straight, section of vein M between crossveins r-m and dm-cu strongly approximated, distance between them less than half of r-m length (Fig. 14).Figures 3, 9 Diagnosis.Thorax predominantly brown, except post-pronotal lobe, notopleuron and small areas on mesopleuron yellow; abdomen yellow with a narrow brown band on distal margin of tergites or completely brown (Fig. 3); scutellum swollen, largely yellow, except for 3 black spots on distal margin (Figs 9, 10); wing with Costal vein predominantly yellow, with alternating brown spots, costal cell brown with hyaline margins, cell r 2+3 brown with two large sub-rectangular yellow spots, median transverse band brown, arched and started from costal band, crossing r-m and dm-cu crossveins and reaches to posterior margin of the wing, vein R 2+3 arched anteriorly at the level of the apex of vein R 1 , distance between crossveins r-m and dm-cu equal to the length of r-m (Fig. 15).Geographical distribution (Fig. 19).Brazil* (Acre, Bahia, Mato Grosso do Sul, Pará), Paraguay (Steyskal 1968).Cresson, 1908 Figures 4, 11, 12, 16, 20 Xanthacrona tuberosa Cresson 1908: 97, pl. 6 Diagnosis.Body yellow to orange yellow, except for abdomen with very narrow brown bands on posterior margins of tergites (Fig. 4); scutellum with a pair of black high two-domed dorsal elevations, margin of scutellum with three black spots, lateral pair extended ventrally toward lower base of scutellum ; wing with Costal vein predominantly whitish, with alternating dark brown spots, costal cell yellow with two medial and apical indentation, medial one surrounded by narrow dark brown area, cell r 1 brown except for small hyaline area at apex of R 1 , cell r 2+3 predominantly yellow, except for apex brown and two dark brown to black spots, one near to the apex of subcostal vein and the other one at the level of r-m crossvein, median transverse band dark brown, arched and started from costal band, crossing r-m and dm-cu crossveins and reaches to posterior margin of the wing, vein R 2+3 arched anteriorly at the level of the apex of vein R 1 , crossveins r-m and dm-cu distant from each other, distance between them greater than the length of r-m (Fig. 16).

Discussion
Xanthacrona is widely distributed in the Neotropical Region and has already been recorded in countries bordering Brazil (Guiana, Suriname, Colombia, Peru, Bolivia, Paraguay, and Argentina).Two species, X. bipustulata and X. ypsilon, were recorded from the country, both from the Atlantic Forest biome in Rio de Janeiro.
In this work, we expanded the distributions of 4 species of the genus in Brazil, 3 of which are new to the country.This demonstrates that the genus is widespread and occurs in several Brazilian biomes.The distribution of X. bipustulata is extended to the Amazonian biome (Northern Region states of Acre, Amazonas, Pará, and Roraima), to the the Cerrado biome (Northeast Region state of Maranhão), and to the Pantanal biome (Central-West region state of Mato Grosso do Sul).In addition, some specimens of X. bipustulata and X. tuberosa were collected in a small and disturbed forest fragment in the city of Manaus, state of Amazonas, indicating that these species may be adapted to adverse environmental conditions.
Most of the studied specimens (both sexes) were collected with light traps, such as a Shannon trap and an illuminated sheet, and it can be inferred that these methods are very effective.
Knowledge of the genus in the Brazil is still scarce.However, the new information, including the diagnoses, photographs, and distribution maps, should contribute to future studies.