This single-celled protozoan infects and kills over 90 species of grasshoppers, locusts, and some species of crickets. Nosema Iocustae is non-toxic to humans, livestock, wild animals, birds, fish, and pets. Should be applied early in the season as over-wintering hoppers emerge. Apply 1-2 pounds per acre, broadcasting around entire infected area as well as outlying areas such as drying grasses and fields. A second application may be necessary to treat heavily infected areas 4-6 weeks later. Nosema is applied to large flake wheat bran which serves as a bait. Grasshoppers are attracted to the bran because of its high protein content. After indigesting the bait grasshoppers are infected with the Nosema. The Nosema grows and reproduces in the fat bodies inside the grasshoppers, then begins destroying cells causing grasshoppers to become lethargic, greatly reducing food consumption, and eventually death. In 7-10 days, grasshoppers will begin to move slowly and their food consumption will begin to drop and many may have died or should begin to die. After this time at least 50-60% of the remaining grasshoppers should be infected to the point that they will not live to reproduce, and 25-50% of the survivors will be infected. The disease is contagious and newly hatched grasshoppers become infected by cannibalizing diseased grasshoppers in the area. A cycle is then started and the disease continues throughout the fields and continue through new hatches. Identified and developed by the United States Department of Agriculture during 20 years of research. Nosema was approved on large scale government grasshoppers control programs, and has been successfully used on thousands of acres by private property owners as well as county, state, and government agencies throughout the United States. It has also been approved for usage overseas by U.S.A.I.D.
Environmental and Ecological Risk Assessment
N. locustae has been tested and studied for 20 years, and has been used in the field since 1980. No adverse effects have been reported during the many years of experience with and environmental release of N. locustae. Considering this use history along with the studies reviewed, EPA can foresee no significant adverse effects on nontarget species or the environment from the registered uses of N. locustae.
Human Risk Assessment
The potential risks to humans and other mammals from dietary and nondietary exposure to N. locustae are considered negligible. Existing toxicology studies showed no detectable dose-related effects at any level, as well as the inability of N. locustae to replicate in or accumulate in the tissues of warm blooded animals. EPA requires only that any allergic reactions following exposure to N. locustae be reported by the registrants.
Human Health Assessment Toxicity
N. locustae and other, similar microorganisms do not appear to be hazardous to humans or other mammals. The toxicology studies consideredin support of N. locustae's reregistration included acute toxicity studies, a 90-day feeding study in rats, and an abdominal cavity lining injection study in mice. No adverse effects were noted in any of these 2 studies. N. locustae has been placed in Toxicity Category IV (indicating the lowest level of toxicity) for all acute effects. N. locustae spores seem to be inactivated by passage through the test animal since persistence does not occur in rats fed the microorganism for 90 days.