The usage of insecticide rendered the successful vector control program with the high usage of the pyrethroid. However, the intensive and extensive use of pyrethroid, causing resistance in Aedes aegypti and hampered the control program. Knockdown resistance (kdr) resulting from the Voltage-Gated Sodium Channel (VGSC) is one of the mechanisms of resistance in pyrethroid group insecticide. Investigating the phenotypic status of Ae. aegypti mosquitoes is a lead in knowing the current resistance status and as an indicator of the genotypic resistance. In this study, we investigate the resistance in phenotypic and genotypic of Ae. aegypti with a new kdr mutation point A1007G was detected. Using the adult bioassay, we tested the phenotypic resistance from the Selangor state against 0.75% permethrin, 0.05% deltamethrin with and without the addition of PBO synergist. Permethrin-resistant and deltamethrin-resistant, including susceptible samples, were subjected to genotyping analysis on mutation point in domain II and domain III of Voltage-Gated Sodium Channel (VGSC). Adult bioassay revealed that the Ae. aegypti was highly resistance toward 0.75% permethrin and 0.05% deltamethrin. The bioassay with the presence of PBO synergist showed an increment of mortality rate, but Ae. aegypti status is still resistance towards both insecticides. Genotyping result showed that three common kdr mutations (S989P, V1016G, and F1534C) have existed in the Ae. aegypti population. A new novel mutation on A1007G was also detected in this population, which is the first time reported. This study has brought a piece of information on the current resistance status in Ae. aegypti in Malaysia. The detection of new mutation point of A1007G has added the knowledge on the resistance in mosquitoes. Thus, this study will aid with the decision making in the usage of insecticides in the vector control program; before this invaluable insecticide rendered ineffective in killing mosquitoes.
We examined the olfactory and visual abilities of megachiropteran bats, Cynopterus sphinx, for discrimination of the odour and shape of the banana fruit, Musa sp. We conducted the experiments in captive conditions by offering a selection of ripe bananas, blended bananas and artificial bananas. The behaviour of the bats was observed visually, and the percentage of activity and rest, duration of the first foraging bout, number of feeding attempts and the average duration of successful attempts was recorded for each bat. The bats exhibited an increased number of visits to ripe bananas and blended banana fruits. However, the artificial fruit did not evoke any response. Our study suggests that odour cues are more important than visual cues for the location of fruits by C. sphinx.