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Professor of Geography, Department of Education, State of Parana, Brazil
Received date: May 09, 2013; Accepted date: June 17, 2013; Published date: June 19, 2013
Citation: Garcia CM (2013) Analytical Test on the Environmental Constraints Related to Accidents with the Lonomia Obliqua Walker 1855, in Southern Brazil. J Ecosys Ecograph 3:125.doi:10.4172/2157-7625.1000125
Copyright: © 2013 Garcia CM. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and and source are credited.
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This paper is an analytical essay on the study of environmental conditions, related to accidents with the Lonomia obliqua Walker, 1855. From the considerations raised by the various researchers, about what’s next for leading to the increase in the number of accidents with this insect was doing a survey seeking to understand how environmental aspects represented by population growth, urban growth, the change of use and coverage of the soil and climate can act in its development. For this structured a survey covering six municipalities in the southern region, and two of each State (Parana, Santa Catarina and Rio Grande do Sul). He has been trying to work with the notifications that are indicative of the number of accidents with the L. obliqua. A study was elaborated within the geographical environmental health vision, taking into account the study prepared by Max Sorre, Pathogenic complex. It was used as the ecogeography methodology, which focuses on the relationship man-nature. With census data (1980,1991, 2000 and 2010), satellite imagery (time trial) and climate data, we tried to understand the interference of these elements in the increase in the number of accidents from 1989 to 2009. Although we have not done the field count of insects, the assumption that the increase in the number of accidents can be indirectly indicating the increase in the number of its population. It was found that the population growth, will be related to greater proximity with the insect population, since this promotes the urban growth and this the occupation of new areas, reducing the insect’s natural environment, leaving the population more susceptible to accidents. With respect to the climate it was observed that there is a constant in temperature values in the municipalities, ranging between 20ºC and 25ºC. Another factor noted was an increase in the volume of rainfall, caused by the action of El Niño and La Niña phenomena that cause an increase in soil moisture. This increased moisture can be acting in insect development and consequently the largest number of accidents.
Lonomia oblique; Urban growth; Climate; Population growth; Ecogeography
Important aspects of human life are intertwined relations between man and the environment. The disordered occupation of the natural spaces has promoted significant changes in existing ecosystems. These changes have created the need to know the forces of nature, plants, animals and everything that surrounds them, in order to achieve safety, health, longevity and prosperity of human beings.
The current geography comes against the relevant environmental changes studies promoted anthropic and natural way and is second puts Ross [1], “the more prepared, more than other sciences for environmental studies because it offers necessary methods with an immense volume of scientific data and information about the natural environment and its resources (...) and its economic use ”.
The geographical space is a changing space represented by changes of urban and rural space, which to their transformations advance on what remains of spaces “called”. It should not be forgotten that all space is geographic, that according to Santos [2] “are determined by the movement of society, production (...), being the result of surface movements and background of the company, a unit operating reality, a mosaic of relationships, of shapes, functions and senses”.
In this context of change and transformation of the space, where the man has been acting as the main intellectual mentor, and he ends up having to adapt, we find animals in search of a new environment where it can adapt to changing the way of survival, this becomes the main element, and the confrontation of these difficulties lead these species to seek a new environment
The poisonous animals are living with the man since his emergence on the Earth’s surface. Over the centuries, knew environmental characteristics, its shape and its venom. Some of these animals while in its natural environment were in equilibrium, reaching humans in several occasions, but in reduced form. From the moment that the man started the changes of natural environments, these animals for the sake of survival and adaptations, start a migration process, reaching more directly the human populations who are approached.
This research proposes to meet the need to know more deeply the current environment in which develops the insect, Lonomia obliqua Walker, 1855, (Figure 1) a lepidopteron of the family Saturniidae, classified as poisonous animal (larval stage), due to a toxin that has been affecting the most varied forms, including deaths, human populations, mostly residents in southern Brazil.
Figure 1: Lonomia obliqua Walker, 1855. Larval stage.
Literature and academic papers about this insect are restricted. Stand out in the context of Brazil researchers Lisete Maria Lorini, Roberto Henrique Pinto Moraes [3-5], who sought to understand in more detail the morphology of this insect, its natural enemies, as well as put the importance of targeted studies to environmental issues and Garcia [6] that make a study specific to the Parana. International research are Lemaire jobs [7,8], which made the revision of the classification of this insect, in addition to the research of Arocha-Piñango [9,10] about the presence and the toxin of Lonomia sp in Venezuela.
The L. obliqua, is an insect endemic to southern Brazil and Eastern regions as Espírito Santo and Bahia. Your environment is, according to Lemaire [7,8], primary forests of mountainous areas, having its best development in half, that is, between 600 and 1,800 m. Currently it is found in a wide variety of plant species, especially in fruit trees.
The climate is one of the factors that most influence the lives of living beings, it is he who will determine which species of plants and animals, ways of life or functional types can live in an area. The climate can be understood as the sum of the variations in weather conditions (temperature, rainfall, evaporation, wind and solar lighting) of an area and the interaction of atmospheric controls with geographic climate factors will determine the dynamic flow of energy that occurs in several areas of the globe [11,12].
This interaction of atmospheric controls and geographical factors come different climatic zones, which are identified by the intensity of the solar radiation for the redistribution of heat, moisture and wind through distributed by water currents. Are these climatic zones and the elements that make up that will effectively be responsible for maintenance and adaptation of insect in half [13,14].
In addition to the importance of climatic adaptation and maintenance aspects of the insect, anthropogenic interference also becomes an important factor in its development, since it changes the natural balance of the environment into which it is inserted. This interference takes place through the change of this medium (decrease of most vegetated areas, introduction of agriculture or urban growth), forcing the insect to adapt to a new environment.
In addition to the importance of climatic adaptation and maintenance aspects of the insect, anthropogenic interference also becomes an important factor in its development, since it changes the natural balance of the environment into which it is inserted. This interference takes place through the change of this medium (decrease of most vegetated areas, introduction of agriculture or urban growth), forcing the insect to adapt to a new environment.
All of these factors, both as the man-made climate, will determine a new environment of development of this insect.
At the end of the eighties, have been reported in the South of Brazil a series of accidents with the L. obliqua in your larval period, many of these were notifications related to people who have had physical contact with the insect. Until then, notifications about contact with the Lonomia were rare, despite knowing of the existence of same. Accidents generated by this contact with the skin of people characterized primarily by causing irritation and bleeding that occurred in some cases. In 1989 were reported the first cases of hemorrhagic accidents in Rio Grande do Sul and Santa Catarina, which bring great concern the health Secretaries of States, since records of deaths caused by these accidents were happening.
It was noticed that these accidents occurred at the beginning of the spring and summer, in rural areas and in urban areas. In your larval stage, this insect parasite species plants, other fruit trees like peach tree (Prunus pérsica) to the exotic Sycamore (Platanus spp.).
In several studies about L. obliqua, both in its morphological aspect, as in medical aspect, some hypotheses were being raised, trying to justify the increase of insect population. These hypotheses are based on the influence of population growth and expansion, the changes caused in the use and soil coverage, responsible for insect migration of primary vegetation areas, rural and urban areas to settling fruit trees; in climate influence and the role of temperature and humidity in its development since the appearance of these has greater intensity, when the climatic phenomena El Niño and La Niña gain contours more damning in southern Brazil [6].
The environment in mind in balance and in the process of urbanization relating this fact to the growth in the number of notifications with the L. obliqua, relates the idea of Max Sorre [15] on Pathogenic and multiple causes Complex since this is causative agents, vectors acting on the event, the environment and the man himself. The increase of notifications of L. obliqua can be not just a variable either anthropogenic or natural, but rather of all of these.
From the considerations raised by the various researchers, we opted to do this research, trying to understand how environmental aspects represented by population growth, urban growth and the change of use and soil cover can interfere in the development and spread of L. obliqua, as well as the influence of climate on the possible development of this insect, in the southern region of Brazil.
This research aimed to present the current panorama of the area in which has been developing the L. obliqua in southern Brazil, including the changes in the environment in which this insect develops, to bring more effective actions to parameters of the secretariats of health, for the sake of society.
Specifically sought to analyze the reason that is leading to significant increase of individuals, from the characterization of some environmental parameters in the municipalities of their occurrence, as well as understand the relationship between the El Niño and La Niña phenomena and the incidence of notifications with the insect.
Limited to the South of Brazil because of insect endemic in the region, be chosen by six municipalities representatives States, one with a large number of notifications and another with few notifications of this insect. For this choice took into account monthly and annual data confirmed notification listed in information systems of the departments of health and of information sent by the TICs (Toxicological Information Centers) and their municipalities, as well as factors such as number of inhabitants and physical performance aspects of the area were chosen the municipalities of Cruz Machado and Sao Mateus do Sul in the State of Parana; Chapeco and Curitibanos in Santa Catarina and Passo Fundo and Encruzilhada do Sul in Rio Grande do Sul (Figure 2). It should be remembered that the data pointed to about L. obliqua present the problem of reliability not depending on how this information come to the secretariats introduction of health, often different. For this reason the data presented are those confirmed by these institutions.
Figure 2: Location of the areas under study.
Regarded as one of the richest regions of Brazil, the southern region is made up of three Brazilian States: Parana, Santa Catarina and Rio Grande do Sul. European colonization is conspicuous by their States agricultural excellence, not leaving behind considerable industrial park development.
With a population of approximately 27.386.891 inhabitants [16] (IBGE- The Brazilian Institute of Geography and Statistics/census 2010), the South of Brazil has an area of 563.802.077 km2, configuring a very large variation of inhabitants per km2, much of this area is devoted to agricultural production.
Your industry is focused on agribusiness, food production, footwear, wine and the textile industry. This region became a representative in the industrial sector, from the early 1990, because until this period its industrial growth was not significant. Today, the industry has been developing apace [17].
The value of the HDI (Human Development Index) is 0.831 and is considered one of the most highest of Brazil, giving her upcoming features to those of the developed countries. Conditions of employment, education, health, and factors related to urbanization, put this region on the national and international spotlight. Located between the Parallels 22° S and 33° S put the entire area, with the exception of the northern part of the State of Parana, within the Subtropical Zone. This fact will differentiate the region from the rest of the country, typically tropical. These climatic characteristics give Southern States certain characteristics such as the presence of occasional snow during winter and strong influence of extreme climatic phenomena as Hurricane Catarina, El Niño and La Niña and the performance of sporadic tornadoes [18].
In its physiography, the southern region differentiates itself from other regions, as it features a variation of relief: plateaus, Plains, hills, mountains, canyons, Islands. Its plateaus are well marked, with mountains of higher altitudes to 1000 meters, two large sets will stand out: the Serra do Mar and Serra Geral. The topographic situation in the region has a significant contribution to the development of the insect, since the high altitude can be one of your environmental restrictions.
From the geographical approach applied in the area of environmental health and taking into account the Pathogenic Complex proposed by Max Sorre, where according to Peckenhayn et al. [19] “the human being might be considered a special integral system because it operates on all biological and environmental complex, ensuring the permanence or the decline of the relationships between the elements”, that is, the relationship between man and the environment include the action of nature (biological and physical environment) about the man and the human action modeling nature [20].
Assuming it was established above, sought to define how methodological application, ecogeography, area of research which also focuses on the nature company. The theme under study has a multicausal bias that fits in the concept of ecogeography, since these increases the understanding of society-nature relationship, i.e. “she studies how humans are integrated into ecosystems and how this integration is diversified in terms of terrestrial space” [1,21].
The concept of ecogeography has been developed by Tricart and Kiewietdejonge [22], which distinguishes three levels of organization in the world [1].
i. The Organization of matter - characterized by the arrangement of the particles that make up (physical state of matter);
ii. the Organization of life that involves a willingness to play accompanied by a growing trend and organization of a set of shapes, the reverse of the material things (living things);
iii. the social organization is based on the creation of forms of social and economic organization from a cultural base (socialeconomic);
Thus the study of the development environment of L. obliqua was carried out from the investigation of variables: population growth, change in use and land cover and climate elements, changes that occurred from the performance of extreme phenomena, pointed out by studies of Lorini, Moraes and Garcia [3-6] as probable causes of the development of this insect.
Limited to the South of Brazil, in reason of endemism of the insect, we chose to work with six municipalities two of each State, being a city with a large number of notifications and other municipality with few notifications of the presence of this insect. For this choice took into account monthly and annual data confirmed notification listed in information systems of the departments of health and of information sent by the CITs (Toxicological Information Centers) and their municipalities, as well as factors such as number of inhabitants and physical aspects. Were chosen the municipalities of Cruz Machado and Sao Mateus do Sul in the State of Parana; Chapeco and Curitibanos in Santa Catarina and Passo Fundo and Encruzilhada do Sul in Rio Grande do Sul. It should be remembered that the data pointed to about L. obliqua present a problem of reliability not depending on how this information come to the health departments.
To outlining the research, a literature review of recognition of insect morphology, to then make the verification of environmental characteristics presented by him.
Sought to characterize in general environmental aspects of each State and individualize the information related to the chosen municipalities with the presence or absence of the insect. By means of a comparative table between observations of Claude Lemaire [7,8] on the physical environment of the insect and the inherent characteristics of the municipalities, we tried to verify the influence of population growth (urban and rural population) and changes in land cover and use.
On the characterization of the municipalities in its aspects of population growth, demographic census data were carried out by IBGE (Brazilian Institute of Geography and Statistics) [16,23-25], for visualization of changes in these municipalities, which were compared with each other and among the other municipalities under study correlating them with the number of notifications (Figure 3).
Figure 3: Graphic used for verification of population growth.
For verification of the constant changes in the process of urbanization and changes in use and land cover using four images of different years, but with months within the matching as closely as possible contemplating a period of 20 years. The images used are from the Landsat 5 TM sensor Satellite, being used the bands 3, 4 and 5, being composed in the form RGB (Red, Green, Blue), these were made available free of charge in the Imaging Division (DGI) of the National Institute for Space Research (NISR), being handled in Arcgis 9.2. To avoid misunderstanding on behalf of cultivation periods in these municipalities, as already mentioned above, we tried to find images of different years, with months. These images were cut within the limits of municipalities, and later worked for the preparation of a map of land cover and use prepared in Spring environment 4.3, using a scale of 1: 500,000 and 1: 550,000, depending on the image, which gave an overview of the changes that have occurred in the municipalities in question (Figure 4).
Figure 4: Land use Maps used for analysis of urban growth.
On a map of land cover and use, were worked 4 variables, namely: vegetation, no matter the size, the agriculture, being that this was in various stages of cultivation, that is, periods of planting, tillage and crops themselves, in addition to the bodies of water and urban areas.
To understand what the climatic operating environment in which the Lonomia obliqua Walker, 1855 has been developing over the last twenty years, we decided to use the same municipalities chosen for socio-environmental characterization due to the detail already performed in chapter v. For this point sought information on minimum and maximum monthly temperature average, rain and moisture on existing stations in the municipalities or municipalities coming over a period of 20 years (1989-2009). The data were provided by Embrapa Trigo, Passo Fundo, to the city of Encruzilhada do Sul, by the Centre of applied Meteorology Fundacao Estadual de Pesquisa Agropecuaria- FEPAGRO/SCT, Curitibanos and Chapeco were ceded by the Ciram/ Epagri/Inmet. The data for the municipality of Curitibanos were used from the municipality of Campos Novos for temperature (maximum, minimum and average) and humidity and ANA data (national agency of waters) in the municipality for information on the rains. In Parana, the municipalities of Cruz Machado and Sao Mateus do Sul, had their rain data collected by the Institute of Parana, for the first and by Copel for the second, and the temperature and humidity for these municipalities were ceded by Fernandes Pinheiro station, with data from Inmet.
To understand the role of temperature in the development of L. obliqua made graphics that indicate the maximum, medium and minimum temperatures of all municipalities. The use of maximum temperature and minimum temperature is linked to the calculation of the thermal amplitude, since she is a factor that influence on the development of the insect. After the identification of thermal amplitudes assessed as her behavior occurred with notifications of L. obliqua in each municipality.
Put excel data on humidity, rain, and monthly period (1989-2009), where graphics were prepared with a view to the interpretation together with the number of notifications of each municipality. We tried to evaluate this data between them and between States, looking for similarities and differences. In the same environment developed graphics composing evapotranspiration/notifications, evapotranspiration/precipitation/ notifications.
As L. obliqua, has its pupae stage on the substrate that is around the trees that uses as hostess, there is a need that this environment have suitable moisture for their full development. To verify this factor, we used the Climatological Water Balance proposed by Thorntwaite and Matter [26] of municipalities to identify the water balance of the studied period and during performance of El Niño and La Niña phenomena.
For the preparation of the water balance of the municipalities used the program prepared by Rolin and Sentelhas [27], where data were inserted on the municipality, such as altitude, latitude, CAD (available water Capacity) to be used, the analysis period, in this case, the analysis was performed by full time (1989-2009), that generated the graph of water balance for the period, indicating the behavior of this element in the municipalities (Figure 5).
Figure 5: Graphics used for the evaluation of climatic elements.
It was to establish a comparison chart between the cities with highest and lowest number of notifications to observe similarities and differences pointed out by graphics generated. This process of comparison took place between the cities by State and between States.
The calculation of moisture content has been carried out to identify what the default behavior of moisture during periods of performance of El Niño and La Niña. For its calculation was necessary to make the water balance of the occurrence of phenomena by checking if there was surplus or water deficit, as well as the value of the potential evapotranspiration.
This research has shown some important points in the knowledge of some environmental factors and its relationship in the development of Lonomia obliqua. In its population growth factor on the grounds of non-traceability of accidents is in the rural area or in urban was limited to the population growth of cities in the study did not provide direct interference in the biological cycle of the insect or in their proliferation. The main issue in the case of specific population growth this population susceptibility related to contact with the insect in its larval stage and preventive measures must be observed by the locals.
Some points can be observed from the Table 1, built in order to better show the relationships between the municipalities, the population growth, the rate of urbanization and the number of accidents with the insect.
| Municipalities | Total Population Census 2010 | Number of accidents with L.O | Accident Incidence Rate (%) |
|---|---|---|---|
| Cruz Machado | 41.257 | 69 | 0.167 |
| Sao Mateus do Sul | 18.040 | 0 | 0 |
| Chapeco | 183.530 | 43 | 0.023 |
| Curitibanos | 37.748 | 3 | 0.008 |
| Passo Fundo | 184.826 | 134 | 0.072 |
| Encruzilhada do Sul | 24.534 | 3 | 0.012 |
Table 1: Relationship between the number of inhabitants and accidents with the Lonomia oblique (Source: IBGE [16]).
It was found, when looking at this table, which Cruz Machado, despite being in third place in the population is what has increased incidence rate of accidents, followed by Passo Fundo and Chapeco, municipalities with the largest population and highest percentage of urbanization. Encruzilhada do Sul and Curitibanos in this sequel, follow in 4th and 5th in incidence rate (each with 3 accidents reported), but when the population is reversed the classification. Sao Mateus do Sul does not have representation in the analysis of these variables.
It was noticed that the municipalities with the largest number of population has increased number of accidents incidence if taken into consideration this factor. In the specific case of Cruz Machado, is first in incidence of accidents, because this inserted into two main areas of environmental protection (APA da Serra da Esperanca and the Bento Munhoz da Rocha) thus avoiding a more effective occupation.
Were also analyzed the variables represented by population growth, changes in use and land cover and urbanization process as a major factor for the increase in the number of accidents with the L. obliqua Walker. It was used as reference to description of Claude Lemaire on the environmental aspects of development of this insect to compose a comparison chart between these and the features presented by each municipality.
This comparative information can be observed in Table 2, which will give greater insight on how to present these municipalities.
| N° de Notif./acid. | Use ans Land Cover corr. | Average Elevation | D.Dem-Hab/km2 | Relief | Rate Urb.% | |
|---|---|---|---|---|---|---|
| Claude Lemaire | Forests | 600 a 1800 m | - | Montainous Regions | - | |
| Cruz machado-PR | 69 | Agriculture Preservation areas | 823m | 12.21 | Wavy Strongly wave | 33.6% |
| Sao Mateus do Sul –PR | 0 | Agriculture Preservation areas | 761 m | 30.79 | Soft wave | 62.3% |
| Chapeco – SC | 43 | Agriculture | 987 m | 294 | Wavy Strongly wave | 92.2% |
| Curitibanos – SC | 3 | Agriculture | 670 m | 39.63 | Soft wave wavy | 90% |
| Passo Fundo – RS | 134 | Agriculture | 690 m | 236.05 | Wavy | 98% |
| Encruzilhada do Sul – RS | 3 | Agriculture | 432 m | 7.32 | Wavy Strongly wave | 69% |
Table 2: Comparative Table between the description of Lemaire and the characteristics of the municipalities under study.
Analyzing the results when evaluated the population growth, it was found that this factor is related to the human susceptibility on the presence of the insect. Municipalities with a population density sharp tend to have the highest number of accidents.
The population growth factor did not become a rule on behalf of the municipality of Cruz Machado presented a low population density, as a result of the limitations imposed by Brazilian environmental laws since in this municipality are entered an area of environmental protection (Serra da Esperanca) and Bento Munhoz da Rocha plant.
The urbanization rates in the specific case of these provinces do not provide parameters to claim that this factor influences the increase in the number of accidents, because it is variable. One cannot say that the municipalities with increased urbanization had the largest number of cases and vice versa.
As to changes in use and land cover, all municipalities have as reference the agriculture economic activity. Much of the most vegetated areas were replaced by agriculture in the period prior to the survey. Municipalities as Cruz Machado and Sao Mateus do Sul have areas of natural vegetation in large proportion, but the presence of vegetation turns out to not become the largest number of accidents factor in these municipalities, since Cruz Machado has the largest number of accidents and in Sao Mateus do Sul, there is the absence of the insect, according to the Secretary of health of the State of Parana.
According to Lara [13] the insects are subject to various factors that influence the survival, development and reproduction: are physical factors, food, substrate, the insects and other animals. According to the author there are two laws governing the influence of these factors, which are the laws of Ecological Tolerance of Shelford, based on the idea that organisms have an ecological minimum and maximum limit, called tolerance, in which limit the animal develops and the law of the minimum of Liebig, which puts that several factors are acting on a body but only one of them is close to the tolerance limit, this will be the limiting factor. This author puts that:
“Natural forests, due to the diversity of botanical species are the most varied species of insects, with corresponding small number of individuals per species, in a perfect balance; but agricultural regions, where the man uses large areas with a single or a few cultures developed a high increase in population only few species adapted to these plants”.
Taking into account what was above, and noting the current environment of Lonomia obliqua, it was observed that the increase in agricultural areas can be one of the factors for the increase in the number of this insect, since this fact is given in almost all municipalities, exception is the Cruz Machado, which features other limiting factors for urban and agricultural expansion.
In this way one can indicate that the increase in agricultural areas, with the reduction of the most vegetated areas, is leading the Lonomia obliqua increase your population as a form of adaptation to change in your environment. Apparently this process continue intense and vegetation areas continue to be reduced there is a likelihood that there is a significant increase in the population of the insect, to the extent that this find again balance, that is, to adapt to the new environment, increasing the risk of accidents, if there is no specific control programs or education about the same.
Climate point of view sought to understand the climatic characteristics of the municipalities under study and then analyze how these variables could act in the constant increase in the number of accidents. It was found that the temperature has not been directly influencing the development of L. obliqua. Some points of interest for the municipality can be pointed out, as the thermal amplitude in Encruzilhada do Sul, which proved to be high and could be seen as a limitation to the development of the insect. This fact did not become the rule, because the municipalities in Santa Catarina Chapeco and Curitibanos showed high thermal amplitude and in spite of this, the first presented a comparatively high number of notifications.
Average temperatures of the municipalities have always stood on the porch of between 20°C and 25°C, which may be considered the good temperature of development of Lonomia.
It was realized that the moisture is an important element in the development of the insect. She has always been with values near or greater than 70%, indicating that this may be the ideal index for insect development.
In relation to the rains, the variations occurred mainly due to the presence of El Niño and La Niña phenomena, that increase its volume, they can because of this they are favoring the development of the insect.
The rains are directly related to the issue of moisture, it was noticed that there was a significant increase in the volume of rainfall in periods of performance of climatic phenomena under study, although municipalities are within the range called humid climate. This moisture triggered by actions of both phenomena can create an environment favorable to the development of the insect, mainly in their pupae period, since the water balance points to this fact.
Is this relationship of water balance, because the insect into pupa in the substrate near the trees that inhabit. This pupa requires a level of humidity favorable for its development. In the municipalities surveyed the water balance in the period where this high, showing that the soil was saturated. The moisture content, by action of climatic phenomena El Niño and La Niña showed that all municipalities have a water surplus confirming the assessment indicated by the water balance.
Taking into account the various factors singled out as responsible for the increase in the number of accidents with the L. obliqua in the South of the country, such as the advance of urbanization and consequent change of use and land cover, as well as the agricultural expansion could be responsible for the growing spread of the insect, which took place from the end of the eighties, in addition to the factors as the climate being under the influence of extreme phenomena such as El Niño and La Niña, would be acting positively in the growth of the number of accidents it was noticed that the municipalities in the study, Cruz Machado, and Sao Mateus do Sul in the State of Parana, Chapeco and Curitibanos in Santa Catarina and Encruzilhada do Sul, Passo Fundo, Rio Grande do Sul have diversified features although all were linked to agricultural production. The census data point to a growing shift of the rural population to urban areas. The major change occurred in the eighties, when the populations of these municipalities began to migrate to the big cities as a result of various factors, such as the search for employment, study and improvement in quality of life.
Despite this change of characteristics, these municipalities still have agriculture and agribusiness as a factor of economic growth, giving the community that still lives in these areas the possibility of more frequent contact with the insect. In the case of populations living in cities, or surrounding areas, remain susceptible to this type of contact as a result of the new environment that this insect has been occupying by adaptation.
This factor has unleashed in these cities an occupation often disorganized and chaotic, advancing by spaces before for only agriculture or preservation. The advance of urban areas on the areas of vegetation, this research cannot be observed to the satisfaction, since logging occurred in the mid-20th century, and this analysis is done in the last twenty years. The few remaining areas still suffer pressure from government leaders, organizations and communities.
Chapeco, Encruzilhada do Sul, Curitibanos, Passo Fundo, are its largest area for agricultural production, land use maps prepared for these municipalities, large portions of exposed soil, ready to be worked or in the production process. In this context headquarters cities also have their growing areas, leaving few natural environments or in State of preservation. These facts bring consequences for the natural environment of the insect that without a proper area to develop will advance about new environments seeking their survival.
It is necessary to open a parenthesis on the municipalities of Parana, Cruz Machado as above is the only municipality that has a population greater than rural urban population, in addition to being the lower rate of urbanization. This city has its area included in the two areas of environmental protection, which means that there are legal limitations on use and soil cover. These facts mean that, along with physical characteristics attached to them, has an ideal environment for the development of the insect and the high rate of notifications.
Urban growth and change in use and soil cover can be seen as a factor for the increase in the number of accidents, since its ecosystem has been suffering significant changes, especially in areas of vegetation in agricultural areas, or changed to urban sprawl.
This is due to some biological factors that govern the lives of insects, they suffer influence of physical factors, the type of food, the substrate, the own insects and other animals, as well as what they are developing under two laws the law of ecological tolerance of Shelford and the law of the minimum of Liebig, as reported. In the case of Lonomia obliqua, the alteration of their natural environment has caused this insect look to adapt to the new situation.
Because it is endemic to southern Brazil, this insect is already in need of some climatic conditions, such as humidity, rain and temperature, since this region entered in the humid climate, according to the Köppen classification. Your environment itself demonstrates this. In the evaluation of these parameters, the climatic elements under study showed different features. In Rio Grande do Sul municipalities, moisture, in the temperature range, Santa Catarina and Parana in the increase in the volume of rainfall is that stood out for possibly influencing the increased occurrence of insect. The most significant element in this research was the moisture that was always high because of increased volume of rains, which occurred due to actuation of the phenomena El Niño and La Niña.
The Lonomia obliqua enters the pupae stage between May and August/September, when notifications with the insect and during your cycle start, inhabits various plant species. When it reaches the pupae period she settles on the substrate near the tree that used to feed and continuity to your cycle. With soil moisture high insect can develop well, if there is any other situation that prevents this fact occurs, this means that more individuals will be generated, increasing the number of caterpillars. An environment with lower humidity can derail a large number of pupae, reducing the population. This can be checked through the result of the study of water balance in the municipalities. The water balance gives the notion of amount of water exists in the soil, showing when there is surplus (saturated soil) or deficit (reduction) of water in the soil. In this study, all municipalities have water surplus in the entire study period, indicating a moist soil, without need for irrigation, in this case a favorable environment for the development of the pupa of L. obliqua.
The factors identified in this study shows that the L. obliqua, comes a process of adaptation to urban/rural environment that presents itself today, for reasons of survival of the species, is changed by human actions and natural, consisting of new plant species, adapted to a climate variable, no longer restricted to primary forests and areas of medium and high altitudes.
This new situation makes that man has to find solutions to living with this species, and proposed actions by the departments of health and educational sectors, so that this insect is known in its amplitude, thus preventing more accidents will occur.
This research showed how some environmental parameters may be acting in the increase in the number of accidents with the L. obliqua. Other points need to be explored for better characterization of this insect. Related searches not only with the number of accidents, but also through the field control the number of insects in the regions of higher incidence, this is need to check more blunt the influence of climate on insect development.
Another important factor to be verified, due to the proximity of the cities of Cruz Machado and Sao Mateus do Sul, where a featured a significant number of accidents while the other is not, even though they have the same physiographic characteristics. It is here that the only difference is related to the type of soil, which could be related to insect presence not in Sao Mateus do Sul, because in M Cross basalt origin and soil in this municipality of sedimentary origin with the presence of oil shale.
It was noticed that the reduction in the number of accidents in all municipalities could be related to a more effective performance of health Secretaries of these States, not indicating a reduction of the population of the insect, thus further studies in this area should be carried out, seeking information or not this population reduction.
Another point to be evaluated is the change of the type of vegetation that this insect has inhabited in his Caterpillar. A large number of reports in which there is the identification of Lonomia obliqua vegetation pointed to are the fruit trees. This fact raised questions about why this preference and what would be inducing this insect to choose this type of vegetation.
As the conditions evaluated in this work, were based on data relating to the study of climate, topography, vegetation, and number of accidents rather than the insect itself, would be of great importance to develop specific jobs where this was present to confirm the results.
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