Occurrence and seasonality of muscoids dipterous (Diptera, Calliphoridae) at Colégio Pedro II campus Niterói, Barreto, Niterói, RJ, Brazil

This study was carried out by a group of high school students of Colegio Pedro II, campus Niterói, from 2015 through 2016 and was supported by the Junior Scientific Initiation Program supervised by the Dean of Graduate Studies, Research, Extension and Culture of this same institution. The purpose of the program is to familiarize students with scientific research methods and analytical tools. The research presented in this article aimed at knowing the fauna of Calliphoridae (Diptera) in Barreto, a borough in the city of Niterói, Rio de Janeiro, Brazil, focusing on the quantity of predominant species found in the area. Flies were weekly captured at Colégio Pedro II campus Niterói, with the help of a cylindrical metal trap, containing sardine baits. The data collected consisted of 1308 specimens, which were properly identified using a stereoscopic microscope and properly dichotomous keys. Chrysomya megacephala (Fabricius, 1794) was the most abundant species collected. Chrysomya species (Robineau-Desvoidy, 1830) usually have a strong connection to the environment modified by man. They compete with native species and they have a medical and veterinary significant role. It is important that studies continue to be carried out across the Brazilian territory so that they could help create programs to control and fight these insects.


INTRODUCTION
The purpose of a scientific initiation research is to allow students to familiarize themselves with scientific research methods and to learn how to use scientific analytical tools. Bearing this in mind, this study was carried out from 2015 through 2016, with the support of the Institutional Scholarship Program for Junior Scientific Initiation supervised by the Dean of Graduate Studies, Research, Extension and Culture of Colégio Pedro II (PROPGPEC).
The focus of this study was on the fauna of muscoids dipterous (Calliphoridae family) found at Colégio Pedro II campus Niterói, since the identification of many of this family species have medical and sanitary importance. Furthermore, they have a major forensic role. The Calliphoridae family has an invaluable role in the medical and veterinary area, as some of the species are vectors of pathogenic agents of several parasitic diseases (Queiroz et al., 2005). The forensic role also needs to be mentioned in this article because larvae of necrophagous species deposited on a dead body can help establish the postmortem interval (Salviano et al., 1996).
Three species of Chrysomya (Robineau-Desvoidy, 1830) were introduced in Brazil via ships coming from Africa and were moored in the south of the country (Guimarães et al., 1978). This genus of the Calliphoridae family was highlighted by Mello et al. (2007) as being a synanthropic genus in most Brazilian cities that had already been researched. According to Forattini (1992), the constant human environmental actions and rapid urbanization have changed the geographical space, enabling, therefore, new and diverse ecological niches that can be filled with native and exotic species. This is the case of Chrysomya megacephala (Fabricius, 1794), which is considered an "R" strategist, capable of colonizing different habitats and spreading themselves (Pianka, 1970). Several Brazilian researchers have reported the high frequency of this species in urban areas. C. megacephala has been collected by means of different types of bait and has been observed replacing indigenous species (D'Almeida &Lopes, 1983 andMilward-de-Azevedo, 1999). According to Sordillo (1991), C. megacephala was the species of Calliphoridae with the biggest amount of samples collected from the three habitats studied in Rio de Janeiro city (forest, rural and urban areas). This species showed a huge variation of synanthropy, which suggested that it has a strong capability of adapting themselves to the human-changed environment.
Knowing the geographical distribution and seasonality of the Calliphoridae species will help identify the regions where public prevention, diagnosis, and treatment of several medical and veterinary diseases have to be implemented. D' Almeida & Fraga (2007) highlighted the importance of researching the population of calyptrate Diptera in Niterói city, Rio de Janeiro, due to the lack of scientific studies in the area.
The purpose of this study is to analyze the Calliphoridae fauna found in the muscoids dipterous collected at Colégio Pedro II campus Niterói in order to engage high school students with researching practices in Biology. By doing so, these junior researchers will be able not only to interpret data and evaluate or plan scientific and technological interventions but also to understand the interaction between organisms and environment, in particular those related to human health. During the weekly capturing of flies, the students used a handcrafted trap made of a cylindrical can with two diametrically opposed openings for the flies to get in. A sardine was placed inside the can to be used as a bait, as suggested by Nuorteva (1963) and previously used by D' Almeida & Fraga (2007) in their studies. The outside of the can was painted with mat black color as high temperatures (around 27 o C) are more effective in attracting flies (Fraga & D'Almeida, 2005). A plastic black mesh cone with a 2cmdiameter top opening was fitted on the top end of the can. The opening of the cone was directed to the outside and was covered with a transparent plastic bag which was attached to the can by its base. This type of trap had been previously used by Sordillo (1991) and was hanged on branches of bushes around the campus, at 1.20 m from the ground.

MATERIALS AND METHODS
The adult samples collected were preserved in bottles containing alcohol 70%. The samples were then categorized by the date they were collected until they were properly identified. The identification would later be done by using a stereoscopic microscope and applying the key to the species of Calliphoridae by Carvalho & Ribeiro (2000). Moreover, during the collection period, the maximum and minimum temperature data were obtained at accuweather electronic site (https://www.accuweather.com/). The best-conserved samples were pinned and added to the permanent collection of the Laboratory of Biology of Colégio Pedro II campus Niterói.

RESULTS
The specimens of Calliphoridae captured numbered 1308 and belonged to the following five species: Chrysomya megacephala (Fabricius, 1794), C. putoria (Wiedemann, 1818), C. albiceps (Wiedemann, 1819), Lucilia cuprina (Wiedemann, 1830) and Chloroprocta idiodea (Robineau-Desvoidy, 1830), as described in Table 1 and Figure 1. In Figure 1, it can be observed that from all the specimens collected, almost 50% were Chrysomya megacephala, the most abundant of all. The quantity of Chrysomya putoria and C. albiceps captured were practically the same. Only a small number of Lucilia cuprina was collected and only one specimen of Chloroprocta idioidea was captured. Also, as it was noticed in Table 1, the quantity of female specimens collected was higher. The data presented 70% female and 30% male out of the total of the Calliphoridae caught. A very interesting fact was observed during the month of January 2016: all the females collected had their ovipositors extended.  The species of Calliphoridae were more frequent during the months of March, April (fall), August and September (end of winter and beginning of spring) (Table 2 and Figure 2). These were the months when the average high temperatures were ranging between 27.6 o C and 30.2 o C and the lower average temperatures were varying between 18.1 o C and 22.8 o C (Table 3).
As observed in Table 2

DISCUSSION
In one year, only five species of Calliphoridae were captured at Colégio Pedro II campus Niterói.
The genus Chrysomya was predominant, representing 98.4% of muscoids dipterous studied. While Ferreira (1984) was carrying out studies on Chrysomya in Goiania -a city in the state of Goiás -, he observed that C. albiceps, C. megacephala and C. putoria can generally be found in urban areas, in different environments such as street-markets, garbage dumps, and public markets. In several occasions, the three species could be found sharing the same animal abdominal viscera or human feces. When analyzing the rate of synanthropy among several species of calyptrate Diptera from the Calliphoridae, Fanniidae, Muscidae e Sarcophagidae families, Sordillo (1991) observed that the Calliphoridae family was the one  with the highest number of individuals collected. The individuals of the genus Chrysomya were more attracted to the traps containing fish or chicken gizzard. According to Lima;Luz (1991), the species of Chrysomya were well adapted to the tropical regions where the environment was modified by men, and through the process of adaptation, these species of Chrysomya altered the fauna of the areas mentioned above.  (Carraro & Milward-deAzevedo, 1999); northern region of Rio de Janeiro city (Lopes, 2000); Paracambi (Mello et al., 2004); Baixada Fluminense (Rodrigues- Guimarães et al., 2008); Itaboraí (Batista-da-Silva et al., 2010) and Vassouras (Macedo et al., 2011). Chrysomya megacephala is the most synanthropic species found in most Brazilian cities where captures were made.
It is worth observing, however, the spots where the capturing is made in urban zones for, according to Sordillo (1991), they can influence the types of samples. The author put different types of bait in five areas of Rio de Janeiro city, where the collections were made, such as: (i) at the harbor zone; (ii) at the city bus terminal; (iii) in Salgueiro slum; (iv) at parking areas of Flamengo borough, which in the southern region of the city and (v) at the campus of the Rio de Janeiro State University. The species showed a high variation in the capability of being synanthropic (using a scale from -100 = no species found in the inhabited areas to +100 = high preference to areas very populated). In Salgueiro slum, where the level of anthropic pressure is higher, the index was -62.5, which represents a very low tolerance to inhabited areas.
At the campus of the University, which is an open wooded area and with a little circulation of vehicles, the index was +44.6 showing a preference to inhabit areas. According to Povolny (1971), in their natural habit, As far as baits are concerned, a very interesting fact was observed in January 2016: all female individuals of C. megacephala collected had their ovipositor exposed. As described by D' Almeida & Fraga (2007), the different types of baits used to capture the muscoids dipterous aiming at studying their population showed that baits are not only used as food but also as a substrate for oviposition and mating.
According to Povolny (1971), C. megacephala adults tend to use animal carcasses to lay their eggs on.
(2010) data. The researchers observed a lower number of individuals when compared to the other species of the same genus. The synanthropic index obtained by Sordillo (1991) for C. putoria and C. megacephala had a very similar variation. Population studies, carried out not long after the species were introduced to the country, showed that C. putoria was more abundant at the rural areas while C. megacephala was more common at the coast (D'Almeida & Fraga, 2007).
Chrysomya albiceps was the less abundant species observed at Colégio Pedro II campus Niterói.
Differently, Sordillo (1991) showed that C. albiceps was the second more representative species observed, especially in the rural area. Therefore, the synanthropic index for C. albiceps varied between +4.8 (Flamengo borough) and +6.3 (at the bus terminal), showing complete independence from inhabited areas. The synanthropic index of the collections made solely at UERJ campus showed the preference for inhabited areas (+36.9), which coincided with the studies by Rodrigues- Guimarães et al. (2008). Back in the days when Seropédica was considered a rural area, Carraro & Milward-de-Azevedo (1999) found a large population of C. albiceps.
Although the population studies carried out in several Brazilian cities, such as Campinas (Linhares, 1981); Rio de Janeiro (D'Almeida, 1982;Sordillo, 1991) and Belo Horizonte (Madeira, 1985) reported a high synanthropic index of Lucilia cuprina, only a small number of these individuals was captured in a twomonth period in campus Niterói. In D' Almeida & Fraga (2007) studies at the Valonguinho Campus of Universidade Federal Fluminense, they were also only able to collect a small number of individuals of Lucilia cuprina. This result was associated with its probable competition with species of Chrysomya. Sordillo (1991) underlined that L. cuprina preferred bovine liver and chicken gizzard baits, but these were not used in the study discussed in this article. This preference probably explains the small number of specimens captured at Colégio Pedro II campus Niterói.
In March 2015, only one female of Chloroprocta idioidea was collected. Rodrigues- Guimarães et al. (2008) collected C. idioidea in the forest area of the Baixada Fluminense region. In the population studies of Calliphoridae, carried out by Batista-da-Silva et al. (2010) in Itaboraí, it was also found that this species is typically forest-based.

CONCLUSION
Although there are some differences in the number of species collected in several Brazilian cities, the species of Chrysomya, as ratified by the study at campus Niterói, seem to be the species which better connect to the environment modified by men. The species of Chrysomya compete with native species and have a medical and veterinary significant role. It is important, therefore, that studies across the Brazilian territory continue to be carried out so that they can contribute with programs to control and fight these insects.