Explanation:

• Locusts are herbivorous insects that can be serious pests of agriculture due to their ability to form dense and highly mobile swarms.
• They are species of short-horned grasshoppers. Desert Locusts feed on leaves, shoots, flowers, fruit, seeds, stems and bark. Nearly all crops and plants including maize, sorghum, barley, rice, sugarcane, cotton, fruit trees, vegetables, pasture grasses and weeds. 
• As per the Food and Agriculture Organization of the United Nations, Locusts do not attack people or animals. There is no evidence to suggest that they carry diseases that could harm humans.
• An adult Desert Locust can consume roughly its own weight, about 2 grams, in food every day. Hence only statement 3rd is correct.