Freqüência populacional de Dermatobia hominis (Linneaus Jr., 1781) (Díptera: Cuterebridae) e sua correlação com variáveis climáticas em duas propriedades rurais no sudeste do Brasil

Abstract

Dermatobia hominis (Linneaus Jr., 1781) (Diptera, Cuterebridae), popularly known in English as the Human Botfly or Warble fly, the only species of this genus and endemic to the neotropical region, is a holometabolous insect with an independent phase of life in its adult form and an obligatory parasitic phase in its larval form. In its parasitic phase, the larva is the cause of furuncular myiasis occurring in a large variety of endothermic animals, with most frequent occurrence in cattle, dogs and humans. The lack of information concerning dermatobiosis creates difficulties in its diagnosis. By means of a systematic review of the literature on the subject, it can be verified that this fly shows versatility in its phoresis and has a vast list of phoretic records. Field studies are restricted to observation of its larval form, because its adult form is difficult to observe, making this a rare event. With the intention of evaluating and comparing fluctuation in the population of D. hominis, searching for correlations between the incidence of Botfly larval infestations and climatic factors and their distribution on the body surface of cattle, two areas of study were selected, in which field collections were carried out twice monthly for counting the number of larvae in the herds. Discrepancies were discovered in the average number of larval nodes in cattle between these areas of study. These nodules showed variation in their bodily distribution on the cattle, with a higher incidence in the anterior region, compromising the quality of the animals´ skins for economic purposes. In one of the areas, there was a correlation between the average number of larvae and the temperature and precipitation. These climatic factors are related to edaphic characteristics, influencing the penetration of the L3 larvae and the pupal period. For a greater understanding of the dynamics and fluctuations in the population of D. hominis in these areas, ample monitoring is needed to determine if the results encountered in this study are atypical or influenced by local characteristics. Currently, the demand for research is for methods of controlling the dermatobiosis, with emphasis on integrated plague management. Other deficiencies include following the Botfly´s complete life cycle in the laboratory and understanding certain peculiar adaptations, such as atrophied oral apparatus