Option 1: Beriberi - This is not an insect-borne disease. Beriberi is a nutritional disorder caused by a deficiency of thiamine (vitamin B1) in the diet. It is not transmitted through insects.

Option 2: Kala azar - Also known as visceral leishmaniasis, this is an insect-borne disease caused by the bite of infected sandflies. The sandfly acts as a vector, transmitting the parasite Leishmania from infected humans or animals to healthy individuals.

Option 3: Malaria - This is an insect-borne disease caused by the bite of infected female Anopheles mosquitoes. The mosquitoes act as vectors, transmitting the parasite Plasmodium to humans.

Option 4: Plague - This is an insect-borne disease caused by the bacterium Yersinia pestis. While the primary mode of transmission is through fleas that infest rodents like rats, the fleas themselves are considered insects and play a role in spreading the disease.

In conclusion, the correct answer is option 1, Beriberi, as it is not an insect-borne disease.