Agriculture Reference
In-Depth Information
When rotenone has been injected into animals, tremors, vomiting, incoor-
dination, convulsions, and respiratory arrest have been observed. These effects
have not been reported in occupationally exposed humans.
Commercial products currently available include Foliefume, Noxfish,
Noxfire, Nusyn-Noxfish, PB-Nox, Prentox, Chem-Fish, Rotacide, and Rote-
none Solution FK-11
4.
Sabadilla
Sabadilla consists of the powdered ripe seeds of a South American lily. It
is used as a dust, with lime or sulfur, or dissolved in kerosene, mainly to kill
ectoparasites on domestic animals and humans. Insecticidal alkaloids are those
of the veratrin type. The concentration of alkaloids in commercial sabadilla is
usually less than 0.5%. Little or no sabadilla is used in the United States
today, but there is probably some used in other countries.
Toxicology and Mode of Action
Sabadilla dust is very irritating to the upper respiratory tract, causing
sneezing, and irritation of the skin.
Veratrin alkaloids are apparently absorbed across the skin and gut, and
probably by the lung as well. Veratrin alkaloids have a digitalis-like action on
the heart muscle (impaired conduction and arrhythmias).
Although poisoning by medicinal veratrin preparations may have occurred
in the remote past, systemic poisoning by sabadilla preparations used as insec-
ticides has been very rare or nonexistent.
5.
Bacillus thuringiensis (Bt)
Several strains of the Bacillus thuringiensis are pathogenic to some in-
sects. The bacterial organisms are cultured, then harvested in spore form for
use as insecticide. Production methods vary widely. Proteinaceous and nu-
cleotide-like toxins generated by the vegetative forms (which infect insects) are
responsible for the insecticidal effect. The spores are formulated as wettable
powders, flowable concentrates and granules for application to field crops and
for control of mosquitoes and black flies.
Toxicology and Mode of Action
The varieties of Bacillus thuringiensis used commercially survive when
injected into mice, and at least one of the purified insecticidal toxins is toxic
to mice. Infections of humans have been extremely rare (two recognized
cases) and no occurrences of human toxicosis have been reported. From stud-
ies involving deliberate ingestion by human subjects, it appears possible, but
not likely, that the organism can cause gastroenteritis. Bacillus thuringiensis
