A sample of Aedes aegypti L. from Santiago de Cuba with a high level of deltamethrin resistance (113.7 x at the 50% lethal concentration [LC50]), was subjected to deltamethrin selection to determine the capacity of this population to evolve higher resistance under intensive laboratory selection pressure, to characterize that resistance, to attempt to identify some of the mechanisms involved, and to use it as a reference strain for future molecular research. High resistance developed after 12 generations of selection (1,425 x). After selection for 12 generations with deltamethrin, the Santiago de Cuba colony (SAN-F12) showed little or no cross-resistance to the organophosphates evaluated, but high cross-resistance was observed for all the pyrethroids in larvae from this strain: lambdacyhalothrin (197.5 x), cypermethrin (45 x), and cyfluthrin (41.2 x). Adult bioassays reveal that a SAN-F12 strain was resistant to the pyrethroid and the organochlorine dichlorodiphenyltrichloroethane (DDT). Synergism tests implicated detoxifying esterase or glutathione S-transferase (GST) and monooxygenase in pyrethroid resistance. Biochemical tests reveal that acetylcholinesterase was not involved in deltamethrin resistance. The frequency of GST enzyme increased from 0.43 in Santiago de Cuba to 0.88 in SAN-F12. Esterase frequency increased from 0.12 in Santiago de Cuba to 0.63 in SAN-F6 and it diminished to 0.38 in SAN-F12. The polyacrylamide gel electrophoresis and inhibition study suggests the presence of elevated esterase activity not associated with pyrethroid resistance. The presence of both DDT and pyrethroid resistance in the SAN-F12 strain suggests the presence of a knockdown (Kdr)-type resistance mechanism, although the frequency of this mechanism was low. Resistance to deltamethrin could be associated with esterase or GST mechanisms, and more investigation is required. This information contributes to the improvement of resistance management strategies in the Cuban Ae. aegypti control program.

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Mosquitoes are the most important arthropods from the point of view of public health, due to the fact that they can transmit a large number of pathogens which can cause diseases to humans and animals. Aedes aegypti (L.) is one of the most important vector species in the world, since it can transmit numerous pathogens such as dengue, Zika, and chikungunya. Therefore, studies involving the molecular aspects of this and other mosquitoes species are currently increasing. In this report, we describe the comparison between two DNA extraction techniques, Chelex and cetyltrimethylammonium bromide (CTAB), for carrying out DNA extraction in larvae, pupae and adult female of Ae. aegypti. The Chelex technique was superior in the amount and purity of DNA as compared to the CTAB technique in the three life stages we tested.

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Los dípteros conforman uno de los principales grupos de insectos descomponedores de materia orgánica, destacando varias especies de la familia Calliphoridae y Chrysomya rufifacies (Macquart)ha sido consignada como la principal especie califórida colonizadora de carroña en la Comarca Lagunera de Coahuila. Durante primavera y verano del año 2010 se estableció un experimento para estudiar el desarrollo larval así como conocer el ciclo de vida de C. rufifacies. Éste estuvo dividido en dos etapas en las instalaciones de la Universidad Autónoma Agraria Antonio Narro-Unidad Laguna. Enla primera etapa se usaron cuatro carcasas de pollo, mientras que en la segunda fueron usadas cuatro cabezas de cerdo como necrotrampas. Se colectaron hembras grávidas de C. rufifacies, las cuales fueron criadas y alimentadas para obtener huevos y estudiar el ciclo de desarrollo hasta adulto. Se midieron cinco larvas cada cuatro horas, tanto en longitud como en diámetro, además de registrar el cambio de estadío en cada medición. Se registró la temperatura del cuarto de cría diariamente y se calcularon lasUnidades Calor Acumuladas (UCA) necesarias para completar el ciclo de C. rufifacies. En primavera C. rufifacies necesitó 192. 57 UC y en verano 190.69 UC para pasar de huevo hasta la emergencia deladulto. En ambas etapas la larva de esta especie pupó a las 96 horas después de la eclosión (HDDE). Con los resultados de este trabajo se contribuye al conocimiento de la biología de C. rufifacies así como también se incrementa la base de datos sobre fauna sarosaprófaga de la Comarca Lagunera y en especial de Torreón, Coahuila.