Forcepsioneura machadorum (Coenagrionidae: Protoneurinae) sp. nov. from the Cerrado Biome of Minas Gerais, southeastern Brazil

The Neotropical genus Forcepsioneura is composed of 11 species that inhabit almost exclusively the Brazilian Atlantic Forest domain, with F. sancta (Hagen in Selys, 1860) being the only species of this genus known to occur in the Cerrado biome. Here we describe a new species of Forcepsioneura from the Cerrado of Minas Gerais State, Brazil. This new species is morphologically closer to F. sancta and can be separated from this and other species of Forcepsioneura mainly by the rectangular shape of male prothoracic hind lobe and cerci morphology


Introduction
The genus Forcepsioneura was proposed by Lencioni in 1999 to include species with male cercus presenting an internal apophysis (mediobasal process) and a vertically directed branch (ventrobasal process), a character combination which he proposed to differentiate Forcepsioneura from Phasmoneura species.

Materials and methods
Specimens were collected in the field with the aid of an entomological net, placed in rectangular envelopes, frozen for 12 hours and fixed with absolute ethanol before drying. Habitus of holotype and paratypes was scanned with an Epson V600 (Epson America, Long Beach, CA) Perfection at colored 1200 dpi with 200% magnification. Structure images were made from multiple photographs focused at different levels, using a Canon EOS T3i (CANON USA Inc., NY, USA) digital camera coupled to E-Zoom 6 V stereomicroscope (Edmund Optics (Barrington, NJ, USA)). Free hand illustrations were made using trace paper and scanned with an Epson V600 Perfection at black and white 1200 dpi with 100% magnification. Illustrations 2b, 3b, c, e and g were made by Rosser W. Garrison. Morphological terminology follows Lencioni (1999), Garrison, von Ellenrieder, and Louton (2010) and Pinto & Kompier (2018). All measurements are in millimeters (mm).
Acronyms  sciences, especially in odonatology, his wife Prof. Conceição Machado (1936Machado ( -2007 who along with Prof. Ângelo performed several studies on the human autonomic nervous system, mainly on the pineal gland, and their family (children and grandchildren) whom they very much loved.

Type specimen deposition
Holotype and one paratype are deposited at LESTES, two paratypes are deposited at FAAL and one paratype is deposited at LEBIO.

Diagnosis
Forcepsioneura machadorum can be separated from F. sancta and its other congeners by the rectangular shape of the prothoracic hind lobe and the morphology of cerci.

Description of holotype male
Head ( Figure 1). Labium, mandible and genae pale colored; anteclypeus dark brown with a pale spot at the center; postclypeus dark brown; antefrons light green; frons and epicranium metallic dark green, except for a longitudinal pale dorsal stripe along postocular and occipital areas; antennifer dark brown with a pale ring at the apex; antenna dark brown, except for pale coloration on the posterior surface of pedicel; rear of the head pale colored, except for two brown spots on each side of the occipital foramen and a longitudinal light grey stripe on the upper portion. Thorax (Figures 1, 2a). Anterior lobe of prothorax dark brown, becoming paler laterally; medial lobe dark brown except for light brown and pale areas in the propleuron and tubercle; posterior lobe dark brown; medial lobe with two lateral tubercles (cone-like viewed laterally, digit-like viewed dorsally); hind lobe rectangular with a slightly concave medial depression, with posterolateral corners forming right angles (Figure 2a). Pterothorax with mesepisternum and mesepimeron metallic green, except for a light green stripe on the interpleural suture; metepisternum and metepimeron pale colored except for a darker thin stripe at the upper posterior portion of metepimeron and a dark spot on the posterior metepisternum/metepimeron suture; venter pale.
Wings (Figure 1). Hyaline; venation dark brown; Pt dark brown with pale contours; MP reaches anal margin 0.3 cell distal to vein descending from subnodus; RP2 originating at Px 5 in Fw, at Px 4 in Hw; 11 Px in Fw, 9 Px in Hw.
Genital ligula (Figure 2c). L1 smooth, without apparent setae; in lateral view, internal fold roughly triangular, oblique, long, almost reaching the segment above; in ectal view, flexure with a slight concavity; in ectal view, distal margin of L2 rectangular, flat, with only a smooth concavity; flagellae long, curved, flat and wide in their proximal portion, becoming cylindrical and thin towards their apex.
Anal appendages (Figures 1, 3a, d, f). Basal portion light brown, remainder black with a blunt tip; in dorsal view cerci are forcipate, widest at base, gradually tapering distally, with converging apexes; in lateral view directed obliquely dorsad ( Figure 3a); VBP light brown, with a black tip; in lateral view long, forming a right angle with dorsal branch, distal portion almost at ventral level of S10, apex rounded ( Figure 3a  Variation in paratypes. Overall coloration of paratypes similar to the holotype, except for dark spot on the posterior metepisternum/metepimeron suture which is less evident in two paratypes, and one paratype (perhaps a younger one) lacking pruinosity on S9-10. Other observed variations are as follows: MP reaches anal margin 0.5 cell distal to the vein descending from subnodus in three paratypes; 10 Px in Fw, 8 Px in Hw in three paratypes.

Habitat and ecology
The type locality of Forcepsioneura machadorum is located in a small forested area inside a satellite campus of the Universidade Federal de Uberlândia, Fazenda Experimental do Glória (Figure 4). At this locality, the new species was found along a small spring inside a gallery forest. At the same place there are also remnants of Cerrado/semi-deciduous forest ecotone ( Figure 5).

Differential diagnosis
Within Forcepsioneura, considering the length of MP vein in Hw, cercus/VBP ratio, apex of VBP and shape of MBP, F. machadorum is similar to F. sancta. However, the following combination of characters allows for a good differential diagnosis between the two species: while in F. sancta the hind prothoracic lobe is rounded (as in Figure 2b), in F. machadorum this structure is squared with a slightly shallow medial depression, with right-angled posterolateral corners ( Figure 2a); in posterior view, the MBP of F. sancta appears as a squared basal plate ending in a blunt apex (Figure 3e), whereas in F. machadorum the MBP lacks a basal plate, and is cylindrical with a blunt apex ( Figure 3d); in dorsolateral view, MBP is digit-like with rounded apex in F. machadorum (Figure 3f), whereas in F. sancta the apex is bluntly pointed at its anteromesal corner (Figure 3 g). Other characteristics of F. sancta and F. machadorum can be used secondarily in order to differentiate them, such as body coloration: in F. machadorum there is a light green stripe on the interpleural suture, which in some individuals of F. sancta is absent or dark brown, depending on the individual age; the longitudinal pale dorsal stripe covering postocular and occipital areas in F. machadorum also seems to be absent in F. sancta.

Discussion
Forcepsioneura machadorum is the third species of the genus known to occur in the State of Minas Gerais, in addition to F. lucia and F. sancta (Lencioni, 2017;Machado, 2000), and the second one recorded from the Cerrado Biome (Pimenta et al., 2019). Including this new species, there are 297 recorded species in Minas Gerais State according to the literature (Vilela, 2020).
This new species was collected inside a satellite campus of the Universidade Federal de Uberlândia in a small protected forested area. A few meters inside this patch of vegetation there is a spring from which a small stream runs among the trees. This highlights the importance of the preservation of these areas and also encourages sampling efforts on forest remnants because even though it is an area with a certain degree of anthropic activity, it holds several odonate populations inside, including Angelagrion sp., Acanthagrion truncatum Selys, 1876, Heliocharis amazona Selys, 1853, Homeoura lindneri (Ris, 1928), Protoneura tenuis Selys, 1860, Oxyagrion chapadense Costa, 1978, andEpipleoneura williamsoni Santos, 1957.