Question

Select the correctly matched pairs regarding the pest and its biocontrol agent.

A. Ladybird beetle - Mosquitoes
B. Dragonflies - Aphids
C. Bacillus thuringiensis - Caterpillars of butterfly
D. Trichoderma - Plant pathogens

• A. A, B, C and D
• B. C and D
• C. A and B
• D. B, C and D

Answer 1

The correct option is B C and D

Biological control of pests involves the use of natural predators of a pest species, to keep its growth in check. It aims at keeping the population size at a manageable level to maintain a sustainable ecosystem.

Ladybird beetle is a biocontrol agent that is used to get rid of aphids. Aphids destroy crops by sucking the plant sap.

Dragonflies are used to get rid of mosquitoes.

Bacillus thuringiensis (soil bacterium) is a microbial biocontrol agent that produces an insecticidal protein (Bt toxin). This toxin is quite effective against butterfly caterpillars. The spores of this bacterium are mixed in water and sprayed on vulnerable plants like Brassica and fruit trees. When caterpillars feed on it, they get killed by the Bt toxin. These Bt toxins are species specific and do not harm other non-target organisms.

Trichoderma is a free-living fungus found in many root ecosystems. It is highly effective in controlling many plant pathogens.