Timbuktu or to study. By 1300, the population increased to 10,000 and kept increasing until it reached about 50,000 in the 1500s. There is insufficient rainfall in the Timbuktu region for purely rain-fed agriculture and crops are therefore irrigated using water from the River Niger. The main agricultural crop is rice. African floating rice ("Oryza glaberrima") has traditionally been grown in regions near the river that are inundated during the annual flood. Seed is sown at the beginning of the rainy season (June–July) so that when the flood water arrives plants are already in height. The plants grow up to in
Mythimna separata light dorsal stripe, with black-brown lateral stripe along spiracle line. spiracles brown with black rim. Pupae are yellowish brown and shiny. The moth flies from January to April depending on the location. The larvae feed on a range of agricultural plants like "Zea mays", "Sorghum bicolor" and "Oryza sativa" and are thus considered a pest. Caterpillars do not feed on "Momordica charantia" due to the presence of the triterpenoid glucoside called momordicine II, which is a natural inhibitor of caterpillar actions. China experiences periodic outbreaks of northern armyworm infestation. The outbreak in 2012 was particularly severe. Larva can be hand