New genus and species of Schizomyiina (Diptera, Cecidomyiidae) from Brazil

A new gall midge genus, Distinctamyia gen. nov., and a new species Distinctamyia matogrossensis sp. nov. (Diptera, Cecidomyiidae) are herein described and illustrated (larvae, pupal exuviae, male and female). The new species induces conical, green, hairy and one chambered galls on leaf and bud of Simarouba amara Aubl. (Simaroubaceae). Gall-inducer specimens, samples of gall and host plant were collected at Parque Nacional da Chapada dos Guimarães, in the state of Mato Grosso (Midwestern Brazil).


INTRODUCTION
The gall midges of the subtribe Schizomyiina (Asphondyliini) are characterized by adults without apical projection on the first tarsomere of each leg (except for some Schizomyia that may have a small spur), the male's gonostyli have unfused denticles, the females don't have large lobes at the posterior end of the eighth tergite, but occasionally may have a very small one, and the ovipositor is elongate and tapered. The pupa may or may not have prominent antennal bases and usually has projections on the frons, and only the anterior part of the third to eighth abdominal segments is covered by small cuticular spines. The larva may have six or fewer lateral papillae, and a ventral anus (Gagné, 1994;Gagné & Jaschhof, 2021).
There are 157 species in 26 genera of Schizomyiina to the world and this group shows a great diversity outside the temperate Holarctic Region. Most of species occur on Neotropical area and only Schizomyia, the most diverse genus of the tribe, is cosmopolitan, with 56 species known so far (Gagné & Jaschhof, 2021;Ospina-Peñuela et al., 2021).
Simarouba amara Aubl. (Simaroubaceae) occurs in the rainforests and savannas of South and Central America, and the Caribbean (Franceschinelli et al., 1998). In Brazil, it is commonly known as "marupá", where it is found in the phytogeographical domains Amazon rainforest, Caatinga, Cerrado, and Atlantic Forest (Flora do Brasil, 2020). It is used in landscaping, reforestation areas, and in traditional medicine, to treat stomachache, hemorrhoids, dysentery and other diseases (Lorenzi, 1992;Sambuichi et al., 2009;Le Cointe, 1934).
Another gall morphotype was found by the authors in Parque Nacional da Chapada dos Guimarães (National Park of Chapada dos Guimarães), located at Chapada and Cuiabá municipalities, in Mato Grosso state. It is conical, green, hairy, one chambered and occurs on leaves and buds of S. amara (Fig. 1). The inducer is a new gall midge species, which is described here.

MATERIAL AND METHODS
This study is part of the project "Diptera dos estados do Mato Grosso, Mato Grosso do Sul e Rondônia: diversidade, sistemática e limites distribucionais" (Diptera of the states of Mato Grosso, Mato Grosso do Sul and Rondônia: diversity, systematics and distributional limits). This project aimed at inventory the diversity of Diptera from Brazil's North and Midwest regions.
The species herein described was collected on January 2012 in Cidade das Pedras trail at Parque Nacional da Chapada dos Guimarães (National Park of Chapada dos Guimarães). This Park is located at Chapada and Cuiabá municipalities, in Cerrado (savanna) areas, in the state of Mato Grosso (Brazil). The gall ( Fig. 1) was photographed using a digital camera and characterized by the plant organ of occurrence, shape, color, presence or absence of trichomes, and number of internal chambers.
Samples of galls and host plant were collected, labeled and transported to the Laboratório de Diptera Neotropicais (Museu Nacional/UFRJ, Rio de Janeiro), where part of the galls were placed in plastic pots cov-ered with fine screen at room temperature to rear adults. Other samples were dissected to obtain larvae and pupae of the inducer. All specimens were prepared and mounted on slides following the methods outlined in Gagné (1994).
We used the key to Neotropical genera of Gagné (1994) to identify this cecidomyiid, but it did not fit in any known genus. As other genera have been described since then, we examined the literature and compared this gall midge with others described after 1994. We recognized a new genus and species of Schizomyiina, which is described here.
Morphological studies were done using an optical microscope. Drawings were made with the aid of a drawing tube, and photographs were taken using a camera coupled to the microscope. All drawings were scanned and processed in Autodesk SketchBook 4+ and both plates and photographs were processed in Photoshop CS6®. Measurements were made using a microscope slide with scale from 0.01 mm to 5.0 mm.
We designated a male as holotype and males, females, pupal exuviae and larvae as paratypes. All material, including the types, is deposited in the Cecidomyiidae collection of Museu Nacional, Rio de Janeiro (MNRJ). Morphological terminology follows Gagné (1994). The field work was done by Rodrigues, A.R., and the description of the new species by Proença, B. and Maia, V.C.
The host plant was identified by Dr. Gracialda Ferreira and Manuel Cordeiro from Universidade Federal Rural da Amazônia (UFRA) and the exsiccate was deposited in the herbarium of that institution.

Distinctamyia gen. nov., Proença & Maia
Diagnose: Adult: Palpus 1 or 2-segmented. Males and females with irregular and reticulated circumfila. R s vestigial, R₅ slightly curved reaching C just after the wing apex; CuA bifurcated. Tarsal claws simple, bent before its midlenght, empodia shorter than the bend in claws. Male cerci with deep triangular lobes, shorter than gonocoxites; parameres present. Ovipositor protrusible, female cerci fused. Pupa: antennal horns short and simple, frontal horns absent, prothoracic spiracle short, abdominal segments without dorsal spines. Larvae: spatula with two apical teeth, one pair of setose lateral papillae, one pair of terminal papillae with setae subequal in length.

Etymology:
The generic name is composed by two words: "distincta" and "myia". The former means "distinct" and the latter is a suffix frequently used to refer to midges and flies. The specific name, "matogrossensis", refers to the Brazilian state, Mato Grosso, where this species was collected.
In Table 1 is shown a comparison between the morphological features of adults, pupal exuvia and larva of the new genera with those of Brethesiamyia Maia, 2010;Bruggmannia Tavares, 1906;Proasphondylia Felt, 1915 andStephomyia Tavares, 1916.

ACKNOWLEDGMENTS
We thank to Msc. Alene Ramos Rodrigues for the field work and all researchers of the Sisbiota Diptera project. The Sisbiota Diptera project was supported by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), process 563256/2010-9 and FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo), process 2010/52314-0. We are also grateful to the following institutions for their financial support to their researches: BP to Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the PhD scholarship and VCM to Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), process 301481/2017-2.

AUTHORS' CONTRIBUTIONS
Barbara Proença: Writing, editing and drawing. Valéria Cid Maia: Supervision, writing, review and editing. All the authors actively participated in the discussion of the results, they reviewed and approved the final version of the paper.