Navegando por Autor "Faroni, Lêda Rita D'Antonino"

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Allyl isothiocyanate actions on populations of Sitophilus zeamais resistant to phosphine: Toxicity, emergence inhibition and repellency
(Journal of Stored Products Research, 2016-10) Freitas, Rita Cristina P.; Faroni, Lêda Rita D'Antonino; Hadd, Khalid; Jumbo, Luis O. Viteri; Oliveira, Eugênio E.
The risks associated with the use of synthetic insecticides have caused increased interest in the research of essential oils and their main constituents for use in the pest management of stored products. Allyl isothiocyanate (AITC) is the main component of mustard essential oil and has been reported as a potential replacement pesticide for conventional insecticides that control stored product insect pests. Here, we assessed the toxicity (including emergence inhibition) and repellent actions of AITC on Brazilian populations of the maize weevil Sitophilus zeamais (Coleoptera: Curculionidae) resistant to conventional insecticides (e.g., phosphine). We also evaluated physiological (e.g., respiration) and behavioral (e.g., walking and flight) traits of AITC-exposed insects. The AITC showed consistent insecticidal activity against the populations resistant to phosphine and other synthetic insecticides, with LC50 values ranging from 1.5 to 2.9 μL L−1. Significant inhibition of the offspring emergence was achieved after the exposure of parental adults to sublethal levels (i.e., LC1 and LC5) of AITC. Reductions in respiration rates were also registered in all the populations sublethally exposed to AITC. In all five populations, a high number of insects avoided AITC-treated (1.5 μL L−1) grain masses, and although individuals of a phosphine-susceptible (i.e., Abre Campo) population increased walking and reduced flight activities, individuals of another phosphine-susceptible (i.e., Tunápolis) population exhibited higher flight activity under AITC exposure. Thus, our findings suggest that AITC is a potential tool that may be integrated into the control strategies of maize weevils where resistance to phosphine and other conventional insecticides is a problem.
Associação de deltametrina com Acarophenax lacunatus e seu impacto sobre o desenvolvimento de Rhyzopertha dominica
(Pesquisa Agropecuária Brasileira, 2006-08) Faroni, Lêda Rita D'Antonino; Gonçalves, José Roberto; Guedes, Raul Narciso Carvalho; Oliveira, Carlos Romero Ferreira de; Garcia, Flávia Miranda
O objetivo deste trabalho foi avaliar a associação do inseticida deltametrina, aplicado em grãos de trigo, com o ácaro parasita Acarophenax lacunatus e seu impacto sobre o desenvolvimento de Rhyzopertha dominica. Grãos de trigo (13% de teor de água) foram tratados com diferentes doses de deltametrina (0,00, 0,125, 0,25, 0,375, 0,50, 0,625, 0,75, 0,875 e 1,00 mg i.a. kg-1). As unidades experimentais consistiram de placas de Petri contendo 30 g de grãos tratados, ou não, com o inseticida, infestados com 30 adultos de R. dominica. Cinco dias depois da infestação, foram inoculados cinco ácaros parasitas por unidade experimental, em sete repetições. As unidades experimentais foram armazenadas por 60 dias depois da infestação em câmara climatizada ajustada a 30±1°C, 60±5% UR e escotofase de 24 horas. A taxa instantânea de crescimento de R. dominica apresentou índices negativos para as doses de deltametrina maiores que 0,25 mg i.a. kg-1. A. lacunatus associado a doses de deltametrina menores que 0,5 mg i.a. kg-1 reduz as fases imaturas de R. dominica.
Behavioral and physiological responses induced by ozone in five Brazilian populations of Rhyzopertha dominica
(Journal of Stored Products Research, 2017-05) Velasquez, Luz Paola Grisales; Faroni, Lêda Rita D'Antonino; Pimentel, Marco Aurélio Guerra; Heleno, Fernanda Fernandes; Prates, Lucas Henrique Figueiredo
This study evaluated locomotory and respiratory responses induced by ozone at a concentration of 500 ppm in five Brazilian populations of Rhyzopertha dominica (Coleoptera: Bostrichidae). Toxicity and body mass were also assessed to establish their relationship with behavioral patterns. The results indicated that none of the evaluated populations of Rhyzopertha dominica showed resistance to ozone. No significant correlations were observed between ozone toxicity and locomotory behavioral patterns. Moreover, no significant correlations were found between ozone toxicity and the respiratory rate of Rhyzopertha dominica. Ozone is a potential alternative for phosphine resistance management, and its rapid degradation constitutes an advantage for the environment.
Degradation kinetics of pirimiphos-methyl residues in maize grains exposed to ozone gas
(Elsevier Journal of Stored Products Research, 2017-12) Freitas, Romenique da Silva de; Faroni, Lêda Rita D'Antonino; Queiroz, Maria Eliana Lopes Ribeiro de; Heleno, Fernanda Fernandes; Prates, Lucas Henrique Figueiredo
This work investigates the kinetics of degradation of pirimiphos-methyl residues in maize grains exposed to ozone gas and evaluates the effect of ozonation on grain quality. The assays employed maize grains treated with the insecticide, namely Actellic 500 CE® (pirimiphos-methyl), which were exposed for different periods to ozone gas at a concentration of 0.86 mg L−1, provided at a continuous flow rate of 1.0 L min−1. The insecticide residues were extracted from the grains using solid-liquid extraction with low temperature partitioning. The extracts were analyzed by gas chromatography with electron capture detection. Ozone effectively degraded more than 91% of the pirimiphos-methyl residues, with the degradation efficiency increasing in direct proportion to the duration of exposure to the gas. A first order kinetic model provided the best fit to the degradation data. The use of ozone gas did not alter the qualitative characteristics of the maize.
Desenvolvimento do método de extração sólido-líquido com partição em baixa temperatura para determinação de inseticidas em grãos de milho ozonizados
(Química Nova, 2013-10-04) Freitas, Romenique da Silva de; Queiroz, Maria Eliana Lopes Ribeiro de; Faroni, Lêda Rita D'Antonino; Heleno, Fernanda Fernandes; Moura, Vanessa Vaz de
The objective of this study was to optimize and validate a solid-liquid extraction method with low-temperature partitioning (SLE/LTP) for the analysis of pesticides. This method was coupled with gas chromatography (GC/ECD) and used to evaluate the degradation of bifenthrin and pirimiphos-methyl in maize grains on exposure to ozone. The optimized SLE/LTP-GC/ECD method is simple, effective and consumes low quantities of the solvent. It can be routinely used for the determination of bifenthrin and pirimiphos-methyl in maize samples. The use of this method of analysis determined that the levels of the insecticides in maize grains were reduced on exposure of the grains to the ozone gas. The observed reduction in the levels of insecticide was directly proportional to the increase in the concentration of the ozone gas.
Ozone treatment for pesticide removal from carrots: Optimization by response surface methodology
(Food Chemistry, 2017-09-26) Souza, Lauana Pellanda de; Faroni, Lêda Rita D'Antonino; Heleno, Fernanda Fernandes; Pinto, Frederico Garcia; Queiroz, Maria Eliana Lopes Ribeiro de; Prates, Lucas Henrique Figueiredo
The present study aimed to optimize ozone (O3) treatments, as gas and dissolved in water, to remove difenoconazole and linuron in carrots. We employed a central composite design to study three variables governing the efficacy of treatments: O3 concentration, temperature and treatment time. The temperature did not influence the efficacy of treatments. The removal percentage of pesticides increases with increases in ozone concentration and the time of treatment. O3 application promoted the removal of more than 80% of pesticides when the roots were exposed for approximately 120 min at 5 and 10 mg L−1, respectively, in treatments with O3 as gas and dissolved in water. After storage, pesticide removal was higher than 98% for difenoconazole and 95% for linuron. The degradation products from the pesticides resulting from treatment were monitored, but none were found. This is the first report demonstrating the removal of difenoconazole and linuron from carrots by ozone.
Postharvest quality of ozonized "nanicão" cv. bananas
(Revista Ciência Agronômica, 2013-01) Faroni, Lêda Rita D'Antonino; Alencar, Ernandes Rodrigues de; Pinto, Michele da Silva; Costa, André Rodrigues da; Silva, Tales Afonso da
This study was done to analyze the physic-chemical, microbiological and sensory qualities of the banana, after being either dry or wet treatment with ozone. For dry processing, the fruits were directly fumigated with ozone for 30 min. The wet treatment included the ozonization of water for 20 min followed by immersion of the fruit in the ozonized water for 10 min. In both treatments, the utilized gas concentration and flow were 0.36 mg L-1 and 1.5 L min-1, respectively. The quality of the fruits was evaluated at the beginning of storage and after 3; 6; 9 and 12 days. The variables analyzed were: fresh mater loss, total titratable acidity, total soluble solids, pH, pulp/peel ratio, color index of the peel, rot severity, microbiological analysis (total fungi and yeast count) and sensorial analysis. In general, the fruits immersed in the ozonized water presented better quality, in reference to both the physico-chemical and microbiological parameters, as well as have good sensory acceptance among those tested. It could therefore be concluded that treatment with ozonized water is a new alternative for the postharvest handling of bananas.
Potential of Tyrophagus putrescentiae (Schrank) (Astigmata: Acaridae) for the biological control of Lasioderma serricorne (F.) (Coleoptera: Anobiidae)
(Brazilian Archives of Biology and Technology, 2011-01-17) Canevari, Glauco da Cruz; Rezende, Fernanda; Silva, Rafael Braga da; Faroni, Lêda Rita D'Antonino; Zanuncio, José Cola; Papadopoulou, Smaro; Serrão, José Eduardo
This work investigated the potential of Tyrophagus putrescentiae (Schrank) (Astigmata: Acaridae) to control Lasioderma serricorne (F.) (Coleoptera: Anobiidae) in the laboratory. L. serricorne is the most destructive insect pest ever found on stored tobacco. The experimental delineation had 33 arenas being each experimental unit with 11 arenas of experiments with eggs, larva of L. serricorne with the density of T. putrescentiae maintained constant, where from 11 of these arenas, eight were for the analysis of predation and three to evaluate the natural mortality of the insect. The highest predation rate was found during the larval stage with, approximately, 54, 68 and 78% mortality of L. serricorne from the fourth until the sixty day of predation. These results indicated that it was possible to use the predatory mite T. putrescentiae in pest management programs of L. serricorne in the storage units of tobacco.