Question

Choose the odd one among the following with reference to microbes as biofertilizers:

1. Ladybird beetles 
2. Azotobacter 
3. Azospirillum 
4. Rhizobium

Answer 1

Ladybird beetles

Explanation:

Azotobacter, Azospirillum, and Rhizobium are all nitrogen-fixing microorganisms used as biofertilizers to improve soil fertility.
Ladybird beetles are insect predators (they feed on aphids and other pests) and are used as biocontrol agents, not as biofertilizers.