Estudo populacional do mosquito Aedes spp e medidas de intervenção em campo com uso de óleo essencial de Croton rhamnifolioides com efeito deterrente no cemitério da Várzea, Recife, Pernambuco

Abstract

The Aedes aegypti is of great medical importance in the epidemiological diseases transmitted by arbovirus. It is linked to the virus transmission of the Flaviviridae family, responsible for most of the neglected diseases like dengue fever and another 100 other types of febrile diseases. The control of the mosquito from chemical larvicides has been the most used form in the prevention of these diseases, however, Aedes spp populations have become resistant to these compounds, requiring more efficient and less aggressive forms of control to the environment and health. The objective of this work was to evaluate the methods of monitoring and control through two studies on the mosquito vector and to test the efficiency in the field of the of essential oil of Croton rhamnifolioides as deterrent of oviposition. For both studies, the 30 oviposition traps already installed in 20 blocks of the Varzea cemetery, Recife, Pernambuco were used. The eggs collected every 15 days, within 12 months, were taken to the laboratory for counting and later stimulated hatching to identify the species. For the oviposition impedance action test of the oil, the 30 ovitraps were randomly divided into two groups, one with 15 ovitrampas tests, containing the essential oil, and the other with 15 control ovitrampas. The oviposition response was evaluated by counting and comparing the number of eggs in each group of ovitraps. As results, 110,157 thousand eggs were collected during the study period, with an infestation index of 99.8% and an average of 152.8 eggs by ovitrampa per cycle. The blocks had a significant difference in the number of eggs. Regarding the hatchability, 71.6% of the eggs were ruptured, indicating that viable egg larvae had already hatched in the field. Of the 2,964 larvae analyzed, 96% were Aedes aegypti and only 4% Aedes albopictus. In the deterrence study, the traps with essential oil solution showed, in 76% of the cases, an average of 39% fewer eggs than the control traps. In the first nine cycles the difference in oviposition ranged from 30% to 69% less eggs in ovitraps with oil. The Tstud test showed significant difference between ovitrampas test and control. The results confirm that the Várzea cemetery has a high rate of infestation, that the eggs were viable for hatching in a field and laboratory situation and that A. aegypti occurs in a dominant way. In the study of evaluation of the deterrent action, it was concluded that the OE solution tested has dissuasive power even in adverse field conditions, however, it needs additional studies to optimize its deterrent power in the field.