Which species of fungus is used in crop disease control?

'Devine' and 'Collego' are two agricultural substances that are used as

Which of the following are natural insecticides?
$(a)$ Rotenone $(b)$ Pyrethrum
$(c)$ Nicotine $(d)$ Azadirachtin

Biological control of pests is

The species of genetically engineered microorganism that is successfully used in the bioremediation of oil is .........

Identify the incorrect statement.
$(i)$ Bacillus thuringiensis are available in sachets as dried spores which are mixed with kerosene and sprayed on to vulnerable plants.
$(ii)$ $B. thuringiensis$ are used to control butterfly caterpillars,but leave other insects unharmed.
$(iii)$ The toxin of $B. thuringiensis$ is released in the blood of larvae and the larvae get killed.
$(iv)$ By the development of methods of genetic engineering,$B. thuringiensis$ toxin genes have been introduced into plants.