In Brazil, decades of dengue vector control using organophosphates and pyrethroids have led to dissemination of resistance. Although these insecticides have been employed for decades against Aedes aegypti in the country, knowledge of the impact of temephos resistance on vector viability is limited. We evaluated several fitness parameters in two Brazilian Ae. aegypti populations, both classified as deltamethrin resistant but with distinct resistant ratios (RR) for temephos. The insecticide-susceptible Rockefeller strain was used as an experimental control. The population presenting the higher temephos resistance level, Aparecida de Goiânia, state of Goiás (RR(95) of 19.2), exhibited deficiency in the following four parameters: blood meal acceptance, amount of ingested blood, number of eggs and frequency of inseminated females. Mosquitoes from Boa Vista, state of Roraima, the population with lower temephos resistance level (RR(95) of 7.4), presented impairment in only two parameters, blood meal acceptance and frequency of inseminated females. These results indicate that the overall fitness handicap was proportional to temephos resistance levels. However, it is unlikely that these disabilities can be attributed solely to temephos resistance, since both populations are also resistant to deltamethrin and harbour the kdr allele, which indicates resistance to pyrethroids. The effects of reduced fitness in resistant populations are discussed.
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http://dx.doi.org/10.1590/s0074-02762012000700013 | DOI Listing |
Parasit Vectors
January 2025
Facultad de Ciencias de la Salud, Centro de Investigación en Ciencias de la Vida (CICV), Universidad Simón Bolívar, Barranquilla, Colombia.
Background: Aedes aegypti is the primary vector of dengue, chikungunya, and Zika viruses in Colombia. Various insecticides, including pyrethroid, organophosphate, and carbamate insecticides; growth regulators; and biological insecticides, such as Bacillus thuringiensis var. israelensis, have been used to control Ae.
View Article and Find Full Text PDFJ Vector Borne Dis
October 2024
ICMR-National Institute of Malaria Research, New Delhi, India.
Background Objectives: Temephos is being used regularly to control immature of vector borne diseases in various states in India.
Methods: World Health Organization method was used to evaluate larval susceptibility status of Aedes aegypti and Anopheles stephensi against temephos in Dehradun of Uttarakhand.
Results: The results of the study revealed that the larval mortality in different localities ranged from 67.
Toxicon
January 2025
Entomology Research Institute, Loyola Campus, Chennai, 600034, India.
Mosquitoes, as hematophagous ectoparasites, are significant pests and vectors of numerous pathogens, causing diseases such as dengue, lymphatic filariasis, malaria, chikungunya, and Japanese encephalitis in India. This study investigates the potential of natural insecticides derived from plants to combat mosquito populations, focusing on botanical extract from the leave of Sphaeranthus indicus. Specifically, the hexane extract of S.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Biology, Baylor University, Waco, TX, USA.
Anopheles stephensi invasion in Ethiopia poses a risk of increased malaria disease burden in the region. Thus, understanding the insecticide resistance profile and population structure of the recently detected An. stephensi population in Fiq, Ethiopia, is critical to inform vector control to stop the spread of this invasive malaria species in the country.
View Article and Find Full Text PDFParasit Vectors
October 2024
Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, PO Box 983, Phnom Penh, Cambodia.
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