ABSTRACT Plutella xylostella cause severe damage on cruciferous plants all over the world. Farmers in several regions of Brazil report increasing inefficiency of chemical control, even when using high insecticide concentrations. We evaluate here the susceptibility of brazilian diamondback moth populations to the Premio® (Chlorantraniliprole), Dipel® (Bacillus thuringiensis var. kurstaki) and Lannate® BR (Oxime Methylcarbamate) insecticides, frequently used in Brazil. Susceptibility bioassays with five field-collected and two laboratory diamondback moth populations were conducted with increasing concentrations of insecticides up to ten times above the recommended concentration. Extremely high and region-dependent resistances were found in field populations against Chlorantraniliprole and B. thuringiensis, with Resistance Ratios up to 370.0 times for the Camocim de São Felix population. For Oxime Methylcarbamate, we were not able to do Probit analyses for the field populations because of very low mortality rates. Laboratory populations showed resistance to the three tested insecticides with all LC50 concentrations exceeding the recommended doses by at least 3 times. Our results show strong and variable resistance to the three tested insecticides according to the region of origin. To maintain efficient pest control in a large country like Brazil, local levels of resistance need therefore to be monitored by the authorities and reassessment and adjustments of regional doses of insecticides should be implemented as a public policy, to prevent massive spread of insecticides in the field, as well as increases in cases of resistance.

RESUMO Plutella xylostella causa graves danos em plantas crucíferas em todo o mundo. Agricultores em várias regiões do Brasil relatam uma crescente ineficiência no controle químico, mesmo com o uso de altas concentrações de inseticidas. O objetivo deste trabalho foi avaliar a suscetibilidade de populações brasileiras da traça-das-crucíferas aos inseticidas Premio® (Chlorantraniliprole), Dipel® (Bacillus thuringiensis var. kurstaki) e Lannate® BR (Metilcarbamato de oxina), frequentemente usados no Brasil. Os bioensaios de suscetibilidade foram realizados com cinco populações de traça-das-crucíferas coletadas em campo e duas de laboratório e foram conduzidos com concentrações crescentes de inseticidas até dez vezes acima da concentração recomendada. Resistências extremamente altas e dependentes da região foram encontradas em populações de campo para o Chlorantraniliprole e B. thuringiensis, com Razões de Resistência de até 370,0 vezes para a população de Camocin de São Felix . Para Metilcarbamato de oxina, não foi possível realizar a análise Probit para as populações de campo devido baixa mortalidade. Populações de laboratório demonstraram resistência aos três inseticidas testados com concentrações de CL50 excedendo as doses recomendadas em pelo menos 3,0 vezes. Os resultados demonstraram resistência forte e variável aos três inseticidas testados de acordo com a região de origem. Para manter o controle de pragas eficiente em um país grande como o Brasil, os níveis locais de resistência precisam ser monitorados pelas autoridades e reavaliações e ajustes de doses regionais dos inseticidas deveriam ser implementadas como política pública para evitar a disseminação massiva de inseticidas em campo, assim como, aumentos dos casos de resistência.

ABSTRACT Neoleucinodes elegantalis is an important tomato pest in Brazil, occurring throughout the country and resulting in economic losses in agriculture. In several species, biogeographic studies in Brazil indicate the structuring of populations, following the refuge model, with a split between the populations of the northeast and the southeast regions of Brazil. The objective of this work was to analyze the phylogeography of N. elegantalis in Brazil, understanding its population structure and the demographic patterns. Larvae were collected from eight locations throughout Brazil, and the mitochondrial cytochrome c oxidase subunit 1 gene was analyzed. A total of 628 bp in 51 individuals were obtained, showing 12 haplotypes with a haplotype diversity of 0.836. Spatial analysis of molecular variance (SAMOVA) and cluster analysis showed two populations, indicating population structuring between individuals from the northeast (population 1) and southeast (population 2) regions of Brazil. Phylogenetic analysis indicated that the clades corresponding to the groups defined by SAMOVA have a divergence time of 0.2–0.5 million years, suggesting isolation during climatic events and a separation of the two populations coinciding with the predicted refuges to the Atlantic forest.

Classical swine fever (CSF) is an endemic disease in Cuba with significant economic impact on the swine industry, not only for the animal losses, but also for the operating expenses of the national coverage control program (technical staff, surveillance, diagnosis, vaccines, disinfectants, etc.). For implementing more effective control and eradication measures, the epidemiological analysis is necessary for a better understanding of the disease spatial and temporal distribution. With this aim, it was used the information about municipalities with CSF outbreaks during a seven-year period (2007-2013) registered by the Epizootiological Surveillance System. The spatiotemporal scan statistics analysis was performed; a Bernoulli probabilistic model was used to detect clusters of outbreak occurrence. Also, a temporal analysis was made through logistic regression. Three significant clusters (p<0.05) of high rates were detected, two of them from 2007 to 2009 with relative risks (RR) of 1.99 and 1.8, respectively. The third cluster had a RR=2.46 in 2008. Also two low rates clusters were observed, the first with a RR= 0.08 from 2009 to 2011, and the second with a RR= 0.43 from 2011to 2012. Furthermore, a tendency to a decreasing percentage of affected municipalities was observed in the studied period; a low risk of the municipalities to be affected were observed in 2011 (OR: 0.518, 0.332-0.809, I.C. 95%, p=0.004) and 2012 (OR: 0.577, 0.371-0.897, I.C 95%, p=0.015). Finally, to investigate the factors associated with the clusters of disease outbreak occurrence is the next step to progress in the CSF control and eradication campaign in the country.

La peste porcina clásica (PPC) es endémica en Cuba, con un impacto económico significativo en la industria porcina, no solo debido a la mortalidad, sino también a gastos operacionales (personal, vigilancia, diagnóstico, vacunas, desinfectantes, etc.). Para implementar medidas de control y erradicación más efectivas es necesario realizar análisis epidemiológicos para comprender mejor la distribución espacial y temporal de la enfermedad. Con este propósito, se utilizó la información registrada por el Sistema de Vigilancia Epizootiológica sobre los municipios con brotes de PPC durante un periodo de siete años (2007-2013). Se realizó un análisis espaciotemporal mediante scan statistics con el empleo del modelo probabilístico de Bernoulli para detectar conglomerados de ocurrencia de brotes. También, se realizó un análisis temporal a través de regresión logística. Se detectaron varios conglomerados significativos (p<0.05); dos de ellos, de altas tasas, desde el 2007-2009 con riesgo relativo (RR) de 1,99 y 1,8, respectivamente. El tercer clúster mostró un RR= 2,46 y ocurrió en 2008. Asimismo, se observaron dos conglomerados de bajas tasas: el primero con RR= 0,08, desde 2009-2011, y el segundo con RR= 0.43, desde 2011-2012. Además, en el periodo estudiado se observó una tendencia decreciente en el porcentaje de municipios afectados; y los años 2011 (OR: 0,518; 0,332-0,809; I.C. 95%; p=0,004) y 2012 (OR: 0,577; 0,371-0,897; I.C 95%; p=0,015) mostraron un riesgo bajo de afectación en los municipios. Finalmente, investigar los factores asociados con los conglomerados de ocurrencia de brotes es el primer paso para progresar en la campaña de control y erradicación de la enfermedad.