In the presence of a base the blue litmus paper would remain blue.
Explanation:
This is because the litmus paper will react depending on the pH of the solution added. If the solution is acidic pH < 7, the litmus paper will turn red. If the solution is basic, pH > 7 the litmus paper will turn blue. If the litmus paper is blue when a base is added it will remain blue.
This is self-regulation because when the population of the insects becomes too large, it regulates itself and starts to decrease due to a shortage of resources.
