WAEC Biology 2002 Question 38

Which of the following measures is most likely to cause a damage to the ecosystem in the control of pests and weeds?

1. A.Use of ladybird insects to feed on aphids
2. B.Introduction of bacterium to kill larvae of butterfly
3. C.Introduction of Tilapia fish in ponds to feed on mosquito larvae.
4. D.Spraying insecticides to destroy cotton- stainers in a cotton-field.