Invasive species also include disease-causing organisms, such as viruses, bacteria, prions, fungi, protozoans, and internal (roundworms, tapeworms) and external (lice, ticks) parasites that can affect the health of humans, livestock, and pets in addition to fish and wildlife. Then there is the spotted lanternfly, native to East Asia, which is thought to have arrived in Pennsylvania in 2014 and is demolishing orchards and vineyards at a cost of millions of dollars a year. Make sure to clean your clothes, boat, animals, and gear off after recreating to prevent the spread of invasive species to other areas. Mr. Popkin is an independent journalist who writes about science and the environment. d Human impact on temperate forests include A. farming. United States. He has written extensively about threats to trees and forests. [CDATA[/* >