Which one of the following diseases is not transmitted by tiger mosquitoes?

The correct answer is D (Japanese Encephalitis). The tiger mosquito is Aedes albopictus, and Aedes aegypti is also a striped Aedes species. Aedes is the vector for arboviruses such as dengue, chikungunya and yellow fever. Vector specificity is the core concept here.

• Yellow fever: a flavivirus transmitted by Aedes aegypti, the classic urban vector. Wrong option.
• Dengue: a flavivirus spread by Aedes aegypti and Aedes albopictus. Wrong option.
• Chikungunya: an alphavirus transmitted by Aedes species, including albopictus. Wrong option.
• Japanese Encephalitis: a flavivirus transmitted mainly by Culex tritaeniorhynchus, which breeds in rice fields, with pigs and wading birds as amplifying hosts. This is the disease not spread by Aedes.

For Mains, this links to vector control in urban areas, where Aedes breeds in stored water and containers, and to JE control in the eastern UP belt, where vaccination and pig-rearing management matter.

Trap: aspirants assume every mosquito-borne disease comes from the same genus and forget that JE is a Culex disease.