The correct answer is option 2: Male mosquitoes feed on plant juices.

Male mosquitoes do not suck blood. It is only the female mosquitoes that require blood meals in order to lay eggs. Female mosquitoes have specially adapted mouthparts to pierce the skin and draw blood.

While some species of mosquitoes can spread diseases such as encephalitis and malaria, this is not a characteristic specific to male mosquitoes. Both male and female mosquitoes have the potential to spread diseases if they have previously bitten an infected host. However, it is important to note that not all species of mosquitoes are capable of transmitting diseases.

In summary, male mosquitoes sustain themselves by feeding on plant juices, while the spreading of diseases is a characteristic associated with certain species of female mosquitoes.