Butterfly community (Lepidoptera: Papilionoidea) in a transition area of Atlantic Forest and Cerrado in Minas Gerais, Brazil

Fauna inventories function as a database to guide biota conservation policies, such as the creation of Conservation Units, especially in biomes that suffer from habitat loss. This work was developed to survey the butterfly fauna in a transition area of Atlantic Forest and Cerrado in the central-south of the state of Minas Gerais, Brazil, which has potential for the creation of a Conservation Unit. The study was carried out in three forest remnants in the municipalities of Barroso and Prados, from October 2020 to March 2021, using active search and attractive traps to collect specimens. A total of 555 individuals were collected comprising 164 species of butterflies, with Nymphalidae being the richest and most abundant family. Two endemic subspecies of the Cerrado were recorded, Diaethria eluina eluina and Pseudoscada acilla quadrifasciata . In conclusion, the place is home to a relevant butterfly fauna, which ratifies the need for the creation of a Conservation Unit in the region of the municipality of Barroso.


Introduction
In Brazil, the Atlantic Forest and the Cerrado are two important biodiversity hotspots since they have a high level of endemism and endangered species (MITTERMEIER et al., 2011;OLIVEIRA et al., 2021).The Atlantic Forest is one of the biomes that suffers the most from deforestation in Brazil, with less than 8 % of its original cover remaining (WWF BRASIL, 2023), which forms fragments smaller than 50 ha (about 85 %), resulting in a large edge effect, which can be harmful to the functioning of its ecosystems (SANTOS et al., 2018).The Cerrado is also subject to different anthropogenic pressures, such as wildfires and extraction of ornamental species (NEGREIROS et al., 2011;RODRIGUES et al., 2022) and habitat loss due to the expansion of agricultural areas (RAUSCH et al., 2019).
The reduction of natural environments is the main cause of biodiversity loss (ROSSETTI et al., 2017).This justifies inventory studies (an instrument that allows the implementation of effective conservation measures), since knowing the biota is one of the first steps to formulate environmental conservation policies (DOLIBAINA et al., 2011, GIRARDELLO et al., 2019) such as the creation of Conservation Units (CU), which is the main tool for the protection of the biota and of Brazilian natural resources (SALVIO, 2017).
Despite the accelerated reduction of habitats and loss of biodiversity, many areas in Brazil do not have information on the biodiversity of different taxa such as butterflies, insects of the order Lepidoptera, as observed in the state of Minas Gerais (BROWN JR., MIEKE, 1967a, 1967b, 1968;EBERT, 1969 , 2019;VIEIRA et al., 2022;SILVA et al., 2022).Despite this lack of information, about 1,600 species are known, of which 25 are at risk of extinction (CASAGRANDE et al., 1998;COPAM, 2010;ICMBIO/MMA, 2018).
These insects perform essential functions in ecosystems, such as pollination, herbivory, and nutrient cycling (LOMOV et al., 2006), in addition to acting as bioindicators of environmental quality since they are easy to sample, sensitive to environmental changes and have a short life cycle (FREITAS et al., 2006;UEHARA-PRADO et al., 2009;BOGIANI et al., 2012).Based on this, this work was developed to survey the butterfly fauna in a transition area of Atlantic Forest and Cerrado, in the centralsouth of the state of Minas Gerais, which is home to a relevant insect fauna and holds a potential for the creation of a CU.

Material and methods
The study was carried out in the municipalities of Barroso (21°11'13"S, 43°58'33"W), with an area of 8,172.6 ha, and Prados (21°13'33.20"S,44°2'0.56"W, Figure 1), with an area of 2,641.5 ha, in the central-south of the state of Minas Gerais, in the Campo das Vertentes region.Both municipalities are in the transition area of the Atlantic Forest and Cerrado biomes (CARVALHO et al., 1994;MENINI-NETO et al., 2004), forming a vegetational mosaic.The climate is marked by dry winters and hot summers (Köppen classification: CWA), with average annual rainfall of 1,600 mm and average annual temperature of 21°C (REBOITA et al., 2015;MARTINS et al., 2018).Samples were collected in three forest remnants: (A) Lajinha Waterfall, with 32.25 ha; (B) Padeiro Waterfall, with 26.43 ha; and (C) Baú Woods, with 384.9 ha (Figure 1).These remnants are formed by gallery forest, seasonal semi-deciduous forest and grassland, and are generally surrounded by pastures, associated with eucalyptus cultivation (A and C) or used for ecotourism activities (A and B).Wildfires were also recorded before and during the study, particularly at point C. The remnants are located between one and four kilometers from the urban perimeter, with A being the furthest (4 km), B the closest (1 km), and C the intermediate (2.5 km); fragments A and B are about 3.2 km apart, A and C are 7.8 km apart, and B and C are 4.5 km apart.
Butterfly sampling was carried out in four field campaigns, in a total period of six months (October-December 2020; January-March 2021) with 24 days of six hours of collection per day.Two attractive Van Someren-Rydon traps, baited with sugarcane juice with banana fermented for 48 hours (FREITAS et al., 2014), were placed for 72 h in each remainder, resulting in 288 h of sampling effort per trap and totaling 2,304 h.In the active search, with the use of a butterfly net on trails in forest areas and open fields, sampling took place in the morning and early afternoon, when the butterflies are most active: from 9 am to 2 pm (HENRIQUES et al., 2019), totaling 48 hours per fragment.Therefore, the total collection effort was of 2,448 h.
All sampled individuals were sacrificed in the field, stored into insect envelopes with labelling of date and place of collection, and sent for identification at the Laboratory of Systematics and Ecology of Butterflies (LABBOR), at the Institute of Biology of the State University of Campinas (UNICAMP).There, the material was deposited in the Zoological Collection of the Museum of Biological Diversity of the State University of Campinas (ZUEC), Campinas, São Paulo, Brazil.
The sampling effort was evaluated using the bootstrap 1 species estimator using the Estimates 9.1.0software (COLWELL, ELSENSOHN, 2014), with 95 % confidence.To assess the sample sufficiency, a species rarefaction curve was constructed.
The rarefaction curve shows that the richness of butterflies in the region can reach 195 species (Figure 2).

Discussion
The list of species generated is important, firstly, for providing information about the community of these insects, since little is known about the butterfly assemblage in the region (HENRIQUES et al., 2019); and, second, the richness is relevant to the butterfly fauna of the  Cerrado and the Atlantic Forest, since it is similar or greater to other studies carried out in the state (PIRES et al., 2018;PIRES et al., 2020;VIEIRA et al., 2022) even if the studied area is fragmented and surrounded by pasture areas and eucalyptus cultivation, which has a negative impact on the butterfly fauna (UEHARA- PRADO et al., 2007;UEHARA-PRADO et al. 2009;DE BRITO et al., 2021).
The presence of Diaethria eluina eluina and Pseudoscada acilla quadrifasciata, two subspecies endemics to the Cerrado (PINHEIRO et al., 2010) and also recorded in other studies in the biome (EMERY et al., 2006;SAMPAIO et al., 2014), further reinforces the importance of these remnants for the conservation of local biodiversity and highlights the need for conservation measures in the remaining areas of

Legend:
The bootstrap line refers to the expected number of species, the S obs line refers to the sampled number, whereas the dotted lines refer to the error intervals, with 95 % confidence.
Cerrado and Atlantic Forest, as already proposed in the area by Oliveira et al. (2021).
The high richness and abundance of the families Nymphalidae and Hesperiidae were expected, since they are among the families with the highest species richness in Brazil (BONFANTTI et al., 2009), a pattern also described in other studies carried out in Minas Gerais (MOTTA, 2002;OLIVEIRA et al., 2018;HENRIQUES et al., 2019;VIEIRA et al., 2022).Nymphalidae has occupational success, being present in several ecosystems (DEVRIES, 1987), having several feeding niches (BROWN JR., FREITAS, 1999), and being easily attracted and captured by attractive traps (FREITAS et al., 2003;UEHARA-PRADO et al., 2007;VIEIRA et al., 2020), which may explain its high richness and abundance in this study.
The abundance of the species shows the sampling relation with the local landscape and environmental conditions.Hemiargus hanno hanno and Hamadryas epinome, two of the most abundant species, are common in open, anthropized areas, forest edges, and gallery forests (BROWN JR., 1992;SOUZA et al., 2007;RIBEIRO et al., 2012;SAMPAIO et al., 2014).Morpho helenor achillides, a frugivorous and low-flying species (BROWN JR., 1992), has a behavior that favors its survival in areas that suffer fires (NASCIMENTO et al., 2020).Aeria olena olena, on the other hand, is a species found in Cerrado vegetation and near dewy soils (BROWN JR., 1992;BROWN JR., FREITAS, 2000), where its population tends to grow during the wet seasons (FONSECA et al., 2006).All these characteristics are present in the studied area since it is fragmented, with gallery forests and grassland that suffer anthropic action, in which fire outbreaks were observed before and during our work, in addition to the sampling effort having been concentrated in the rainy season and close to humid areas.
The number of species recorded is similar to other studies in the Atlantic Forest (BONFANTTI et al., 2011;VIEIRA et al., 2022) and Cerrado (PIRES et al., 2018).However, some groups were probably undersampled, which would explain the high number of singleton and doubleton species such as the genera Pyrgus, Urbanus, and Hermeuptychia, which have relatively common species in any environment but were poorly sampled in this study.Despite this, according to the Bootstrap species estimator, about 84 % of the butterfly community was sampled in the study area.New visits, at other times of the year, to record seasonal species (RIBEIRO, FREITAS, 2011), and periods known as high species richness (BROWN JR., 1972), would probably be sufficient for a more complete record of the butterfly community in the study area.

Conclusion
The municipalities of Barroso and Prados are home to a relevant butterfly fauna for the state of Minas Gerais, a condition evident by the presence of endemic species.This reinforces the need to create a Conservation Unit for the Barroso region, to ensure the different environmental services provided by these insects.

Figure 1 .
Figure 1.Forest remnants where butterfly community sampling was carried out in the municipalities of Barroso and Prados, central-south of the state of Minas Gerais, Brazil, 2020/2021.

Figure 2 .
Figure 2. Butterfly species recorded in forest remnants in the municipalities of Barroso and Prados, Minas Gerais, Brazil, 2020/2021.