RESUMO
Abstract The effects of temephos resistance on the fitness cost of the wild populations of Aedes albopictus was evaluated. The larvae of two wild populations were exposed to the diagnostic dose of 0.02 mg and 0.012 mg/L. The larvae which survived after the 24 h exposure to diagnostic dose were considered as resistant and F1 generations were chosen for the comparisons of fitness parameters with the control strain, which includes larval developmental time, adult longevity, fecundity, wing length and hatchability. We found that temephos resistance had negative effects on larval developmental time which was longer for Gelugor strain among the populations with the median range of 10 days and a shorter longevity was observed with the median range of 13 days for males and 16 days for females. Whereas, an effective reduction of 29.8 and 38.6% was observed in fertility and fecundity of Gelugor strain as compared to control strain. In contrast, no clear differences were found in biological parameters of Balik Palau and USM strain, except fecundity and fertility with a reduction of 13.4 and 15.5%, respectively. Whereas, no significant differences were seen in the wing size between the populations with the mean length (mm) of 2.40 for Gelugor, 2.44 for Balik Palau and 2.46 for USM control (p > 0.05). Present results indicated that the temephos resistance is associated with the developmental and reproduction potential of resistant population of A. albopictus and the fitness has been compromised.
RESUMO
A resistência de populações de Aedes aegypti a inseticidas químicos tem representado um desafio nos programas para seu controle. Este projeto teve como objetivos caracterizar o perfil de susceptibilidade de populações de A. aegypti de Pernambuco, relacionando-o ao histórico local de uso de tais compostos e aos mecanismos que podem estar associados à resistência. Amostras de A. aegypti de 17 municípios foram analisadas através de bioensaios com o temephos (larvicida) e diflubenzuron (regulador de crescimento) e um adulticida, a cipermetrina. Testes bioquímicos foram realizados para quantificar a atividade das enzimas acetilcolinesterase (ACE), glutationa S-transferase (GST), esterases (Alfa, Beta e PNPA) e oxidases de função mista (MFO). Também foram investigadas mutações no gene do canal de sódio: sítios 982, 1011, 1014, e 1016. Os resultados demonstraram que todas as populações estavam resistentes ao temephos, exceto a de Fernando de Noronha. A razão de resistência (RR) foi moderada apenas na população Recife, enquanto RR 100 vezes foram observadas em 10 populações. Houve uma correlação entre o consumo e a RR a este produto. Para o diflubenzuron foi construída uma linha de base dose resposta e as RR foram correlacionadas positivamente com as observadas para o temephos...
Resistance to chemical insecticides represents a challenge for Aedes aegypticontrol programs. This project aimed to characterize the susceptibility status ofA. aegypti populations fromPernambuco state, associating it to the local use history...