Schizonyxhelea thomsenae (Wirth), description of the pupa and first records from Argentina, Brazil and Peru (Diptera: Ceratopogonidae).

The pupa of Schizonyxhelea thomsenae (Wirth) is described and illustrated from material collected in Misiones province, Argentina. A key for the four known species of pupae of Schizonyxhelea is given, a diagnosis and photographs of the adult are also provided, and the geographic distribution of the species in the Neotropical region is enlarged including first records from Argentina, Brazil and Peru based mainly on adult specimens.

During a fi eld sampling in Misiones province, Argentina, two pupae of Schizonyxhelea were collected. The adults posteriorly emerged were identifi ed as Schizonyxhelea thomsenae (Wirth). Besides, the specimens of Schizonyxhelea deposited in the collection of the División Entomología, Museo de La Plata were studied and allowed us to identify several adult specimens of this species from Neotropical localities. The purpose of this contribution is to describe and illustrate the pupa of Schizonyxhelea thomsenae, to provide a key of pupae of the four known species, as well as to give a diagnosis of the adult and illustrate it. We also enlarge the geographic distribution of this species providing the first records from Argentina, Brazil and Peru.

MATERIALS AND METHODS
The pupae were collected with kick net from a flooded, grassy pond next to the route with an average of water temperature of 29.8°C, pH of 9-10 and conductivity of 243.8 µS/cm. They were carried back to the laboratory and conditioned individually in vials with water. Observations were done daily until adult emergence three days later and when needed, a small amount of water was added to the vial to keep the sample from drying. Adults were allowed to harden for 24 hours before being preserved to ensure its pigmentation was complete.
Material examined: Jamaica, Westmoreland Parish Negril, Crystal Waters Tropical hammock, 20-XI-1968, R. E. Woodruft, 2 males, 2 females, blacklight trap (USNM). New Peru records: Cuzco, Kirigueti, VIII-2004, 2 males, 1 female, J. Williams, at light; same data except Pagoreni, 11°42'21.9" S 72°54'21.9" W, 1 male. New Brazil records: Bahia, Bahia Itabuna, Fazenda Almirante, 6-VIII-1993, 1 male, J. Winder (USNM); same data except 29-XII-1989, 2 males; same data except 3-VI-1988, 1 female; same data except 3-I-1990, 1 female; same data except 7-II-1990, 2 males; same data except 19-II-1990, 1 male. New Argentina records: Buenos Aires: Reserva Natural Integral Punta Lara, 34°47'28" S 57°59'49" W, marginal forest, 10/11-XII-2014, 3 males, 4 females, Cazorla-Campos, CDC light trap; same data except 3/4-II-2015, 3 females; Chaco, Parque Nacional Chaco, 26°48'20. An Acad Bras Cienc (2020) 92(1) e20180500 7 | 9 panamensis is even briefer and incomplete, and it differs from S. thomsenae by the respiratory organ with 7 apical and 2 lateral separated pores on mid portion, and the terminal process which is similar in shape but apparently lack the posterior row of thick spines. Borkent (2014) in his analysis of the phylogenetic relationships between genera, studied pupal exuviae of S. forattinii and S. bulla and interpreted some of the similarities between them as synapomorphies of the genus, as follows: 1, D-1-T much more stout than other dorsal setae; 2, tergite 1 with 1-2 lateral setae; 3, dorsal surface of abdominal segment 9 with two short medial tubercles and 4, terminal process with a posterior row of thick spinules. Our study of the pupal exuviae of S. thomsenae confirms that character states 1 and 4 are shared (both character states are apomorphic conditions), while the character state 3, medial tubercles of segment 9 (apomorphic conditions), is difficult to see in the two studied specimens. Finally, the tergite 1 of S. thomsenae presents 3 lateral setae, which is an apomorphic condition shared with most of the species of the subfamily Ceratopogoninae, unlike the other two species of this genus. Further studies on more species of Schizonyxhelea and with a larger number of specimens are necessary to reveal if the number of lateral setae of the tergite 1, as well as the number of clypeal/labrals sensilla are variable features in this genus.
It is also worth mentioning that the environments in which the immatures were found are similar: S. bulla was obtained from mud from the margins of a marsh, from the grassy margins of a swamp and from weeds of a pond and Sphagnum L.; the larva of S. forattinii was collected from wet mud in a small seep which flowed into the outflow of a larger spring,

TAXONOMIC DISCUSSION
Adult specimens of Schizonyxhelea thomsenae strongly resemble those of the Neotropical species Schizonyxhelea zoologica in size, fused flagellomeres 5−9 or 5−10 and dark coloration of the hind femur, however the later species can be distinguished by the male genitalia with the gonostylus bearing three distinctive crenulations on the mesal surface, and the parameres elongated, slender and rod-like.
Schizonyxhelea bulla, S. forattinii and S. panamensis are the only species of the genus whose pupae are currently known. The pupa of S. forattinii is well described and illustrated, while the description of the pupa of S. bulla is briefer. Both species share with S. thomsenae the following characters: presence of thick spines on the lateral margin of the dorsal apotome, dorsal apotomal sensilla (DA-1-H) represented by an elongate and stout seta, D-1-T much stouter than the other dorsal setae, and short terminal processes. However, S. bulla can be distinguished by the presence of 2 clypeal/labrals and the respiratory organ with 4-7 apical and 3-4 lateral pores, while S. forattinii differs by the short anteromedial setae, the respiratory organ with 5-6 apical and 4 lateral pores and the V-6-IV mediumsized, thin seta. The pupal description of S. and the pupae of S. thomsenae were collected in a flooded, grassy pond.
Finally, it should be noted that Anjos-Santos et al (2017)