Synergy in Efficacy of Fungal Entomopathogens and Permethrin against West African Insecticide-Resistant Anopheles gambiae Mosquitoes

Background Increasing incidences of insecticide resistance in malaria vectors are threatening the sustainable use of contemporary chemical vector control measures. Fungal entomopathogens provide a possible additional tool for the control of insecticide-resistant malaria mosquitoes. This study investigated the compatibility of the pyrethroid insecticide permethrin and two mosquito-pathogenic fungi, Beauveria bassiana and Metarhizium anisopliae, against a laboratory colony and field population of West African insecticide-resistant Anopheles gambiae s.s. mosquitoes. Methodology/Findings A range of fungus-insecticide combinations was used to test effects of timing and sequence of exposure. Both the laboratory-reared and field-collected mosquitoes were highly resistant to permethrin but susceptible to B. bassiana and M. anisopliae infection, inducing 100% mortality within nine days. Combinations of insecticide and fungus showed synergistic effects on mosquito survival. Fungal infection increased permethrin-induced mortality rates in wild An. gambiae s.s. mosquitoes and reciprocally, exposure to permethrin increased subsequent fungal-induced mortality rates in both colonies. Simultaneous co-exposure induced the highest mortality; up to 70.3±2% for a combined Beauveria and permethrin exposure within a time range of one gonotrophic cycle (4 days). Conclusions/Significance Combining fungi and permethrin induced a higher impact on mosquito survival than the use of these control agents alone. The observed synergism in efficacy shows the potential for integrated fungus-insecticide control measures to dramatically reduce malaria transmission and enable control at more moderate levels of coverage even in areas where insecticide resistance has rendered pyrethroids essentially ineffective

5. jornadas hispano-lusas de ingenieria electrica

Three volumesCentro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEIberdrola, Bilbao (Spain)ESSpai

Manejo de Diabrotica speciosa com atrativos naturais em horta orgânica Natural attractios for management of Diabrotica speciosa in a organic home garden

O controle de insetos associados ao cultivo de hortaliças é predominantemente realizado através de pesticidas sintéticos. Entretanto, os riscos do uso indiscriminado dos pesticidas sobre a saúde humana e o meio ambiente deve ser considerado. O objetivo deste trabalho foi estudar a eficácia de atrativos naturais no controle da vaquinha Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae), uma praga de importância econômica na América Latina. Os seguintes tratamentos foram testados: raiz de taiuiá (Cayaponia sp), frutos verdes de porongo/cuia (Lagenaria sp), extrato de folhas de couve-chinesa (Brassica pekinensis), fermentado de frutas, vinagre tinto e água como testemunha. O delineamento foi inteiramente ao acaso, com seis repetições. Os preparados foram acondicionados em armadilhas com garrafas PET de 2.000 ml, com oito aberturas laterais e distribuídas aleatoriamente na área experimental. Frutos verdes de porongo apresentaram captura de adultos de D. speciosa 5,4 vezes maior que raízes de taiuiá e as raízes de taiuiá capturaram 19,7 vezes mais adultos do que a testemunha. Ambas as iscas foram acondicionadas na forma sólida, suspensas internamente na garrafa PET. A menor atratividade foi apresentada pelo extrato aquoso de couve-chinesa, que não diferiu da testemunha. Independentemente do atrativo utilizado, o pico populacional da D. speciosa ocorreu nos meses de fevereiro e março.<br>The control of insects associated with home garden vegetable crops is usually done by sintetic pesticides. However, the risks of the indiscriminate use of pesticides on human health and the environment need to be considered. The objective of this work was to study the attractive efficacy of natural substances on D. speciosa, a very important pest in Latin America. The following treatments were tested: roots of Cayaponia sp., green fruits of Lagenaria sp., water extract of Brassica pekinensis, extract of fermented fruits, red vinegar and water as a control. The experimental design was randomized blocks with six replications. All the tested substances were put into PET plastic bottles of 2L with eight lateral holes and distributed at random in the experimental area. Green fruits of Lagenaria sp. captured the larger number of D. speciosa, 5.4 times more than roots of Cayaponia sp. that captured 19.7 times more than the control tratament. The water extract of Brassica pekinensis had no effect on D. speciosa attraction, and did not differ from the control treatment in the number of captured insects. Independently of the treatment, the population peak of D. speciosa occurred in February and March