A wide variety of species fall within the public-health domain as pests because they have an adverse impact on the health and well being of U.S. residents. This list includes many species of arthropods, vertebrate animals, venomous reptiles and other animals, poisonous plants, and fungi. Some public-health pest threats have similar origins throughout the country, whereas others are unique and require different management approaches.
Arthropods are historically known as major causes of disease. For example cockroaches, flies, mosquitoes, ticks, and fleas are directly involved in the transmission of such diseases as food poisoning, malaria, typhus, viral encephalitis, plague, and Lyme disease. Some arthropod pests bite; sting or cause allergic reactions and others do not envenomate or transmit disease, but are merely annoying.
Arthropods of public health importance are divided into four groups:
- Species that inject their venom by means of fangs or stingers. For example: Spiders, Scorpions, Centipedes, Ants, Wasps and Bees etc.
- Species that inject their venom along with their saliva. For example: Mosquitoes, Midges & Gnats, Lice, Bed Bugs & allies, Conenose bugs & allies, Fleas, Ticks and Mites etc.
- Species that are sources of allergenic emanations and inhalant allergies. For example: Mayflies, Moths & Butterflies densely covered with scales & hairs, Aphids, Caterpillars with urticating hairs, Blister beetles, Millipedes and House dust mites etc.
- Species that do not envenomate but are merely pestiferous. For example: Certain midges become so annoying that they may cause recreational areas to be abandoned. Eye gnats are another example. Also, there are larvae of certain insects that invade body tissues or cavities of humans, causing a condition known as myiasis.
Many vertebrate animals expose humans to dangerous pathogens of public-health significance. Some of these vertebrate pests expose humans to disease organisms without benefit of an arthropod vector, or are primary reservoirs of organisms that cause important human disease. Examples of this type of pest are domestic (house mouse, rat) and wild or sylvan rodents. These rodents can infect humans directly with diseases such as tularemia, leptospirosis, arenavirus, Hantavirus, ratbite fever, lymphocytic choriomeningitis and salmonellosis (food poisoning). They also may serve as reservoirs for diseases transmitted by ectoparasites, such as tick-borne relapsing fever, Colorado tick fever, Rocky Mountain spotted fever, plague, murine typhus, rickettsial pox, Lyme disease, ehrlichiosis, babesiosis and tularemia. Birds, bats and small mammals can be carriers of rabies, histoplasmosis, listeriosis or leptospirosis.
Venomous reptiles (snakes)
Venomous reptiles (snakes) are another group that is of public health importance. There are some dangerously venomous snakes throughout the United States. In North America north of Mexico, pit vipers, which include the cottonmouth moccasin, copperhead, about 20 species of rattlesnakes and 2 species of coral snakes, are the principal venomous snakes.
Poisonous Plants may poison livestock, pets, and humans. Thirty types of plants account for the majority of plant calls to California Poison Centers.