http://hdl.handle.net/11336/34 Articulos de UNIDAD DE INVESTIGACION Y DESARROLLO ESTRATEGICOS PARA LA DEFENSA 2024-04-06T06:07:39Z http://hdl.handle.net/11336/232125 The Response of Susceptible and Pyrethroid-Resistant Blattella germanica (Dyctioptera: Blattellidae) to Shelter-Associated Cues Boné, Emiliano; Gonzalez Audino, Paola Andrea; Sfara, Valeria In this work, it was studied the role of faeces in the location and permanence in a shelter in susceptible and pyrethroid-resistant individuals of Blattella germanica (Linnaeus 1767). Additionally, the effect of different concentrations of palmiticacid on the modulation of these behaviours was tested. A shelter constituted by a square cardboard structure was offered tosusceptible as well as to resistant specimens. The shelter bases were treated with faecal extracts obtained from susceptibleor resistant cockroaches, or with solutions of palmitic acid. The behaviour of susceptible as well as resistant specimens wasanalysed using infrared videography software. Susceptible’s faecal extract attracted both specimens since the time spent bycockroaches to locate the treated shelters was lower, whereas the faecal extract from resistant insects did not elicit any effecton both strains. Faecal extracts showed an arrestant effect on both strains, suggested by the time spent inside the shelter thatwas significantly higher in their presence. On the other hand, treatment with palmitic acid produced an attractant or a repel-lent effect depending on the concentration and strain. The tested lower concentration was attractant to susceptible insects, butdid not produce any effect on resistant ones. In addition, the higher concentrations did not produce any effect on susceptibleindividuals, but resulted repellent for resistant ones. Palmitic acid did not produce an arrestant effect on the strains as therewas not an increase in time spent inside the shelter in the presence of this substance. An increase in the number of visits tothe shelter and to the periphery was also observed in shelters treated with the faecal extract and with the lower concentrationof palmitic acid. These results show that compounds of the susceptible faeces were attractant to cockroaches of both strains,while faecal extracts from resistant insects were not. Moreover, a dual effect of palmitic acid was observed, being attractantat low concentrations and repellent as concentration increased. Additionally, a difference in the concentration threshold atwhich the effect of this substance changes was observed between strains. 2023-08-01T00:00:00Z http://hdl.handle.net/11336/229051 CeO2-ZrO2-Sm2O3 anodes for intermediate temperature-solid oxide fuel cells Suarez Anzorena, María del Rosario; Toscani, Lucía María; Larrondo, Susana Adelina Ce0.9Zr0.1-xSmxO2-δ (0 ≤ x ≤ 0.1) mixed oxides were synthesized for the first time via the citrate-nitrate self-combustion method and, interfaced with 20 % Sm doped CeO2, were studied as metal-free anode materials for Intermediate Temperature- Solid Oxide Fuel Cells. The effect of Sm2O3 incorporation in the Ce0.9Zr0.1O2 structure on the electrocatalytic properties of the anodes under wet H2 and wet CH4 was investigated. The processes involved in the anode performance were identified analyzing the Electrochemical Impedance Spectroscopy results by combining Equivalent Circuit fitting and Distribution of Relaxation Time deconvolution methods. A new anode material with optimized composition (Ce0.9Zr0.04Sm0.06O2-δ), and extremely low polarization resistance without the need of a metallic phase was obtained (0.011 Ω.cm2 and 0.004 Ω.cm2 at 750 °C in 7 vol% H2 and 40 vol% H2, respectively; 0.14 Ω.cm2 and 0.09 Ω.cm2 at 750 °C in 7 vol% CH4. and 20 vol% CH4, respectively). 2023-12-01T00:00:00Z http://hdl.handle.net/11336/225963 Global Pattern of kdr-Type Alleles in Musca domestica (L.) Roca Acevedo, Gonzalo; Boscaro, Ivana; Toloza, Ariel Ceferino Purpose of Review: Houseflies, Musca domestica L., are an important sanitary pest that affects human and domesticated animals. They are mechanical carriers of more than 100 human and animal diseases including protozoan, bacterial, helminthic, and viral infections. Recently, it was demonstrated that houseflies acquired, harbored, and transmitted SARS-CoV-2 (COVID-19) for up to 1 day post-exposure. The most widely used control strategy relays on the application of pyrethroid insecticides due to their effectiveness, low mammalian toxicity, low cost, and environmental safety. The main mechanism of action of pyrethroids is to exert their toxic effects through affecting the voltage-sensitive sodium channel (VSSC) modifying the transmission of the nerve impulse and leading to the death of the insects. Target site insensitivity of the VSSC is due to the presence of single nuclear polymorphisms (SNPs) named knockdown mutations (kdr). In this review, we synthetize recent data on the type and distribution of these mutations globally. Recent Findings: Housefly resistance is reported in several countries. Increased applications of pyrethroids to control housefly populations led to the emergence of multiple evolutionary origins of resistance determined by five amino acid substitutions or specific mutations in the VSSC: kdr (L1014F), kdr-his (L1014H), super-kdr (M918T + L1014F), type N (D600N + M918T + L1014F), and 1B (T929I + L1014F). According to the global map obtained, high levels of resistance to pyrethroids are associated with the L1014F mutation found mostly in North America, Europe, and Asia, while the super-kdr mutation was mostly found in the American continent. The level of protection conferred by these alleles against pyrethroids was generally kdr-his < kdr < Type N ≤ super-kdr ≤ 1B. The relative fitness of the alleles under laboratory conditions was susceptible ≅ kdr-his > kdr > super-kdr suggesting that the fitness cost of an allele was relative to the presence of other alleles in a population and that the reversion of resistance in a free insecticide environment might be quite variable from one region to another. Summary: An adequate integrated pest management program should consider monitoring susceptibility to pyrethroids to detect early levels of resistance and predict the spread and evolution of resistant phenotypes and genotypes. From this review, the pyrethroid resistance status of housefly population was determined in very few countries and has evolved independently in different areas of the world affecting chemical control programs. 2023-03-01T00:00:00Z http://hdl.handle.net/11336/225961 Effectiveness of Essential Oils and Their Components Against Triatoma infestans (Hemiptera: Reduviidae) Sosa, E.; Quiroga, V.; Toloza, Ariel Ceferino Purpose of Review: Chagas disease is a neglected tropical disease caused by the protozoan parasite called Trypanosoma cruzi affecting 7–8 million people in the world. Triatoma infestans (Klug) (Hemiptera: Reduviidae) is the main vector of Chagas disease in the southern cone of South America. Genetic evidence indicates that T. infestans originated in the Cochabamba region, Sucre, in Central Bolivia, where there are jungle sites of this species, and from which the domestic species is believed to derive, currently distributed in Chile, Argentina, Brazil, Bolivia, and Paraguay. Chemical control of the vector by spraying dwellings with pyrethroids has been the most widely used strategy to reduce the incidence of this endemic disease. The long-term use of pyrethroid insecticides in T. infestans control campaigns has led to the development of resistance in treated populations. Recently, there has been great interest in the use of botanical products as new alternatives to synthetic insecticides. Essential oils (EOs) seem to be good candidates due to lesser mammalian toxicity and persistence in the environment. In this review, we summarize recent data on toxicity of EOs and their compounds against T. infestans. Recent Findings: A total of 12 research articles from different sources were reviewed and analyzed to compare the effectiveness of the studied EOs and monoterpenes on kissing bugs. The monoterpenes and the EOs reported in the experimental procedures and their effectiveness against T. infestans are described in Table 1. A total of 22 monoterpenes and 46 EOs were reported and distributed in 12 botanical families. Of these, 18 EOs belonged to the following families: Asteraceae, 8; Lamiaceae, 5; Apiaceae, 2; Anacardiaceae, 2; Buddlejaceae, 4; Verbenaceae, 2; and one each to Monimiaceae, Capparaceae, Umbelliferae, Myrtaceae, Fabaceae, and Labiatae. The main active components of the EOs responsible for the ovicidal and larvicidal properties on T. infestans were menthyl acetate, L-menthone, L-menthol, isomenthol, piperitone, linalool, pulegone, 1,8-cineole, α,β-thujone, limonene, E-anethol, and E-nerolidol. Moreover, the compounds eugenol, 1,8-cineole, linalool, menthol, α-terpineol, and thymol were the most effective inducing hyperactivity (disordered, erratic, and spasmodic locomotor activity). Reported effectiveness varied widely due to the difference in the evaluation methodology and properties of both EOs and monoterpenes. Some of the advantages of using EOs and monoterpenes are that they have little environmental impact because of their low toxicity to mammals and very low environmental persistence. An important finding was the reported synergism on the hyperactivity and mortality effect between eugenol and permethrin on T. infestans. Summary: In recent years, the toxicity of new essential oils and their compounds on T. infestans was evaluated, as well as combinations of monoterpenes with pyrethroids. The latter is the most promising result since it could be a new tool for monitoring the population dynamic. The findings of this work show that certain EOs and their components have insecticidal and repellent potential for their development as formulations for T. infestans. The production of EO is feasible due to its low cost, availability, and accessibility. It is difficult to compare the reported info from literature due to the wide variety of exposure bioassay techniques and chemical extraction methods of the EOs and their compounds. The synergistic effect between eugenol and permethrin on T. infestans suggests that this combination could be a viable alternative of the flushing-out strategy employed in the national control campaigns. Thus, essential oils and their constituents would contribute to delay the development of insecticide resistance in the populations of T. infestans through the combination of these actives with pyrethroids. 2023-09-01T00:00:00Z