Susceptibility status of larval Aedes aegypti mosquitoes in the Western Region of Saudi Arabia

Vector control programs worldwide are facing the challenge of mosquitoes becoming resistant to available insecticides. Larviciding is a crucial preventative measure for dengue control but data on insecticide resistance of larval Aedes aegypti in the Middle East Region are limited. This study assesses the susceptibility status of Ae. aegypti collected from the two most important dengue foci in Saudi Arabia, Jeddah and Makkah, to important chemical and biological larvicides; the organophosphate temephos and Bacillus thuringiensis israelensis, Bti). Whilst worldwide, and particularly in Latin America, high-level resistance to temephos is common, Jeddah and Makkah populations exhibited full susceptibility to both temephos and Bti. Larval bioassays did not detect resistance in Makkah and Jeddah to temephos or Bti where a resistance ratio <5 compared to the New Orleans susceptible strain. These data suggest each can be considered by vector control programs for preventative dengue control in the region, as part of temporal rotations or spatial mosaics to manage insecticide resistance. Larval bioassays did not detect resistance in either Makkah or Jeddah to temephos or Bti (all resistance ratios <5 compared to a standard susceptible strain.

Automated summary

In Saudi Arabia, the Ae. aegypti populations in Jeddah and Makkah show full susceptibility to both temephos and Bti, suggesting they can be used as part of vector control programs for dengue prevention in the region. This data indicates the potential importance of rotational or spatial management strategies to address insecticide resistance.