ABSTRACT
The purpose of this study was to investigate the larvicidal activity of Pterodon polygalaeflorus oil extract against the mosquito vector Aedes aegypti. For this, crushed P. polygalaeflorus fruit underwent solvent extraction to obtain the oil extract. The chemical characterization was performed by gas chromatography coupled to mass spectrometry. For the bioassays third instar larvae of Ae. aegypti were utilized. Tests were carried out to determine the larvicidal activity and the residual effect under laboratory conditions, as well as field screening (small scale). The major components of P. polygalaeflorus oil extract were, respectively, E-caryophyllene, germacrene D and bicyclogermacrene. Lethal concentrations of 50% and 90% were 36.5 and 64.8 ?g/mL respectively. The solution presented a residual effect for seven days and the efficiency of the product was preserved under field conditions. The results encourage continuing studies with the oil extract of P. polygalaeflorus as a research target for bioinsecticides.
Subject(s)
Aedes , Vector Control of Diseases , Polygala , Larvicides , InsecticidesABSTRACT
This work investigated the insecticidal activity of Cashew Nut Shell Liquid (CNSL) extracted from the species Anacardium humile, a native plant in the Cerrado biome, against Aedes aegypti. A. humile fruits were collected and kept in a forced ventilation kiln at 40ºC for seven days for CNSL extraction. Mortality tests were performed on third stage larvae, pupae and adults. In addition, female oviposition behavior, egg viability, and the residual effect of the solution on 3rd stage larvae were observed. The CNSL was diluted in decreasing gradient concentrations to obtain the Lethal Concentration (LC). In oviposition LC99 was used for larvae. Residual effect and oviposition tests were performed with LC99, LC 50 and LC90 were respectively obtained, 6.63 and 11.23 ppm for larvae. No mortality was observed in adults. The residual effect of the CNSL was five days in LC99. A repellent effect of CNSL on the females was noted, with a significant reduction of egg numbers and a change in egg stratification patterns in the oviposition substrate. The larval hatching rate of the eggs exposed to the substrate moistened with CNSL was significantly lower when compared to the control. The results evidenced the insecticidal activity of A. humile CNSL, suggesting it as a promising product in the quest for new botanical insecticides.
Subject(s)
Insecticides , Vector Control of Diseases , GrasslandABSTRACT
This notification presents the occurrence of triatomines captured in the synanthropic environment in the urban area of the municipality of Itumbiara, Goiás. The colonies were found inside homes and on beds, walls, ceilings and counters. They were also found outside the houses on fences, in hen houses, pigeon nests and pigpens. In descending order, the infestation by triatomine species was: Triatoma sordida (99.7%), Rhodnius neglectus (0.2%) and Panstrongylus diasi (0.1%). Only the species T. sordida was infected by Trypanosoma cruzi, with an index of 5.5%.