Question

Which one of the following is used as a biological insecticide?
A. Tiger beetle
B. Caterpillar
C. Silkmoth
D. Majra poka

Answer 1

Bioinsecticides or biological insecticides are organisms that help in protecting cultivated plants from insect pests. They occur naturally in the environment and feed on caterpillars, maggots, ants, aphids and other insects and help in protecting the plant without using any harmful insecticides.

Complete step by step answer: Tiger beetles have long legs, large eyes, thin bodies and sickle-shaped mandibles. They are about 9 to 15 mm in length. They mostly live in fields and feed on spiders, grasshoppers, other beetles and flies. They are the important biological insecticide as they live on soil and feed upon a large number of insects such as caterpillar ants, aphids, maggots and wireworms. They are used as biological insecticides in agroecosystems.
i. Caterpillars are members of Lepidoptera order. They mostly feed on leaves of flowering plants. Caterpillars become butterflies and moth which helps in pollination. They also act as food sources for other animals.
ii. Silkworm feeds on mulberry leaves. It is the larva of the silkmoth. Silkworms are widely used for the production of silk yarn and the process is known as sericulture.
iii. Majra poka is also known as stem borer and is a large group of pests that bore into the stem and feed on inner tissues of the host plant. They are the most damaging pests and mostly attack cereals.
Hence, the correct answer is option A.

Note: Biological insecticides are actual living organisms or the toxins produced by them. Examples include viruses, bacteria, fungi, and nematodes. The chief benefit of using biological, or microbial, insecticides is their low toxicity to humans and nontarget insects.