The conc. of pesticide require to destroy $ 50\%$ of pest is called
$LD 50$
$LC 50$
$LB 50$
$LE 50$
Pheromones are chemicals that are used in animals for
Fumigants are volatile toxicants
Jute fibres are obtained from the
In India, the most popular bioinsecticide is the extract from
Assertion : Lichen is important for chemical industries.
Reason : Litmus and Orcein are formed from lichens.