Impact of olfactory sensitivity preferences on midgut pathophysiology of Aedes mosquitoes towards different sugar variants

The effective control of Aedes mosquitoes are increasingly challenging due to the presence of insecticide resistance in populations of mosquitoes. Hence, attractive targeted sugar baits (ATSBs) can be used as an alternative strategy to insecticides. The introduction of suitable attractant into baits is very crucial since it will determine the number of mosquitoes attracted to it. In this study, the ATSBs were prepared as a medium for liquid bait carriers in the development of mosquito baiting tools. The testing of non-choice and choice assay by Ae. aegypti and Ae. albopictus towards different group of ATSBs (mango, Chrysanthemum and mix) was performed. In addition, olfactory preference index by mosquitoes was calculated using preference index formula followed by independent t- test to determine the significant differences, (p <0.05) between ATSBs pair. Furthermore, the midgut tissue of the mosquitoes was observed by using histology method. The wild and lab strain Ae. aegypti illustrates a strong and significant attractancy towards mango ATSBs with a value of (p = 0.004) and ( p = 0.04) respectively. Mango attractant is the most preferred by the Aedes sp . However, the mix ATSBs is secondarily preferred while Chrysanthemum is the least preferred ATSBs. The histology results show that the midgut of mosquitoes feed on the treated ATSBs exhibit alteration and degeneration. In the prospect of integrated pest management, the ATSBs implementation in mosquito control may reduce the need for chemical insecticides since natural products have naturally occurring volatile emission properties that attract or repel the mosquitoes. Thus, sustain released of the natural attractant odour can be a major part of the attractive toxic sugar bait as an attractant and killing mechanism to overcome mosquito-borne diseases in future.