How do locusts breathe?

Answer 1

Insects do not breathe through their mouths, nor do they have lungs. In fact, insects are equipped with tracheal tubes terminating in pores, called spiracles, running along their abdomens. Insect trachea, much like the structure inside a lung, branch off into smaller and smaller trachea, but end deep in the various tissues of the insect; here, oxygen and carbon dioxide are exchanged continually. Due in part to the largely-passive gas exchange, insects are unable to 'breathe' very fast. This limitation is probably one reason why insects remain relatively small. It is possible to protect some plants from pests by spraying them lightly with castor oil (for example) as the oil effectively blocks their spiracles, suffocating them.