First data about the preimaginal morphology of Austroscaeva occidentalis

Preimaginal morphology of Austroscaeva occidentalis (Shannon, 1927) is described for the first time, and the morphology of larvae and pupae of Dioprosopa clavata (Fabricius, 1794) is updated based on material obtained from captive rearing of wild females from Argentina and Venezuela, respectively. We describe the morphology of the third instar larva, head skeleton and puparium using optical microscopy, cryo-scanning and scanning electron microscope. The immature stages of both New World flower fly species are analysed and compared with the known preimaginal morphology of other taxa that belong to the evolutionary lineage of Eupeodes-Scaeva, where Austroscaeva Láska, Mazánek & Mengual, 2018, and Dioprosopa Hull, 1949, form a Neotropical radiation within, together with the genus Notosyrphus Vockeroth, 1969. Larvae of all members of this lineage have abdominal segments 5 and 6 with the tips of the locomotory prominences facing posteriorly, and the anal segment with a characteristic U-shaped grasping organ. Two other larval synapomorphies of this group of genera are the presence of metathoracic setae accompanying ventral sensilla, and the abdominal segments 1–7 with an extra lobe on each locomotory prominence. These two last characters cannot be assessed for Macrosyrphus Matsumura, 1917, and Lapposyrphus Dušek & Láska, 1967, based on published information on larval descriptions. Despite a similar colouration pattern of the fully grown larvae, larval morphology of A. occidentalis and D. clavata are quite distinct. The preimaginal morphology of A. occidentalis has a mixture of morphological characters from the taxa Scaeva Fabricius, 1805, Semiscaeva Kuznetzov, 1985, and Dioprosopa. The larvae of D. clavata show several unique diagnostic features, such as the presence of a slightly serrate outline due to the great development of the segmental spines and a pinnate ornamentation of the setae of its dorsal and dorsolateral sensilla. Regarding their biological cycle, the length of the preadult stages of A. occidentalis is almost 5 days longer than the length observed for D. clavata. In addition, new DNA barcodes are provided for A. occidentalis.Financial support was provided by the programme ‘Doctorar en el extranjero’ of the National University of Cuyo, Mendoza, Argentina

Identification key for the genera of Syrphidae (Diptera) from the Brazilian Amazon and new taxon records

Identification keys are essential to properly recognize taxa, and a photographic key not only addresses that issue but can also attract the interest of the general public if designed correctly. Syrphidae is one of the largest families of Diptera, and the Brazilian Amazon holds more taxon records from this family than currently reported. The aim of the current study was to provide an updated photographic identification key, of easy use and access, to the genera of Syrphidae (Diptera) from the Brazilian Amazon region, and identify previously unrecorded taxa. Through a literature review and study of collection material from several institutions, I found 36 new taxon records for the Brazilian Amazon (15 are first records for Brazil) and provided a list of references with identification keys to species from each genus. The online version of this manuscript has a photographic identification key, with diagnostic pages for each genus, as supplementary material.Chaves de identificação são essenciais para reconhecer táxons, e uma chave pictórica material suplementar. atende a essa demanda e também desperta o interesse do público em geral, se for desenhada apropriadamente. Syrphidae é uma das maiores famílias de Diptera, e a Amazônia brasileira possui mais táxons dessa família do que registrado atualmente. O objetivo deste estudo foi prover uma chave de identificação pictórica atualizada, de fácil uso e acesso, para os gêneros de Syrphidae (Diptera) da Amazônia brasileira, e identificar táxons ainda não registrados. Através de uma revisão da literatura e estudo de material de diversas coleções, eu encontrei 36 novas ocorrências de táxons para a Amazônia brasileira (15 sendo primeiros registros para o Brasil) e disponibilizei uma lista de referências com chaves de identificação para as espécies de cada gênero. A versão online desse manuscrito possui uma chave de identificação pictórica como material suplementar