African armyworm "S. exempta" larvae feed almost exclusively on Poaceae, also called Gramineae. Poaceae is a family of flowering grasses which includes cereal grasses and the grasses of grasslands and pastures. The species targets most cereal crops, including maize, sorghum, rice, millet, and other grasses. Young caterpillars are also known to feed on wheat and oat seedlings. The larvae eat the upper and lower surfaces of the plant tissue first, preferring to feed on younger and recently germinated crops. Studies have shown that two larvae can completely consume a 10-day-old maize plant with 6-7 leaves, indicating the devastating potential of a high-density
Organisms involved in water purification and to generate toxins in some cases. The choice of organism depends on the local climate different species and other factors. Indigenous species usually tend to be better adapted to the local environment. The choice of plants in engineered wet-lands or managed lagoons is dependent on the purification requirements of the system and this may involve plantings of varying plant species at a range of depths to achieve the required goal. Plants purify water by consuming excess nutrients and by providing surfaces upon which a wide range of other purifying organisms can live. They also are effective oxygenators in sunlight.