*5.3.3 Herbicides*

Even though the main purpose of using different herbicides is to control the unwanted weed populations in the fields and there is no such objective to kill insects through them. The toxicity level of herbicides is known to be very less to most of the insects and due to this these pesticides are applied without any restrictions regarding insects. Bees usually come across these chemicals in higher concentrations [79] and toxic effects of these have also been reported on honey bees. Toxicity levels in LD50 values differ from one chemical to another with a range of 14.5–100 μg/bee (**Table 7**). A widely used herbicide, paraquat has been reported to be toxic to the bees in laboratory conditions, causing median life of worker ten times reduced than the normal, on injecting at the rate of 15 μg per worker and death within a span of 3 days' time, when sprayed at the rate of 4.5 kg AI/ha [79]. These pesticides may harm the bees in other way around as well as they reduce the number of plants offering floral resources to the bees.
