This movement of folding inwards is energetically costly for the plant and also interferes with the process of photosynthesis. Distribution and habitat Mimosa pudica is native to the tropical Americas. It can also be found in Asian countries such as Singapore, Bangladesh, Thailand, India, Nepal, Indonesia, Taiwan, Malaysia, the Philippines, Vietnam, Cambodia, Laos, Japan, and Sri Lanka. It has been introduced to many other regions and is regarded as an invasive species in Tanzania, South and Southeast Asia, and many Pacific islands. It is regarded as invasive in parts of Australia and is a declared weed in the Northern Territory, and Western Australia although not naturalized there. Control is recommended in Queensland. It has also been introduced to Uganda, Ghana, Nigeria, Seychelles, Mauritius and East Asia but is not regarded as invasive in those places. In the United States, it grows in Louisiana, Florida, Hawaii, Tennessee, Virginia, Maryland, Puerto Rico, Texas, Alabama, Mississippi, North Carolina, Georgia, the territory of Guam, and the Virgin Islands. Predators Mimosa pudica has several natural predators, such as the spider mite and mimosa webworm. Both of these insects wrap the leaflets in webs that hinder the responsive closing. Webbed leaves are noticeable as they become brown fossilized remnants after an attack. The Mimosa webworm is composed of two generations that arise at different seasons. This makes prevention difficult and requires proper timing of insecticides to avoid aiding other predators. Once the larvae become steel-gray moths, they are harmless to the plant but lay more eggs. Agricultural impact The species can be a weed for tropical crops, particularly when fields are hand-cultivated. Crops it tends to affect are corn, coconuts, tomatoes, cotton, coffee, bananas, soybeans, papaya, and sugar cane. Dry thickets may become a fire hazard. In some cases it has become a forage plant although the variety in Hawaii is reported to be toxic to livestock. In addition, Mimosa pudica can change the physico-chemical properties of the soil it invades; total nitrogen and potassium, for example, have been seen to increase in significantly invaded areas. Phytoremediation Thirty-six native Thai plant species were tested to see which conducted the most phytoremediation of arsenic polluted soils caused by tin mines. Mimosa pudica was one of the four species that significantly extracted and bioaccumulated the pollutant into its leaves. Other studies have found that Mimosa pudica extracts heavy metals such as copper, lead, tin, and zinc from polluted