E X T O X N E T
Extension Toxicology Network
A Pesticide Information Project of Cooperative Extension Offices of
Cornell University, Michigan State University, Oregon State University, and
University of California at Davis. Major support and funding was provided
by the USDA/Extension Service/National Agricultural Pesticide Impact
Publication Date: 9/93
TRADE OR OTHER NAMES
Trade names of this product are Ryanodine and Ryanicide.
Ryania is a botanical insecticide made from the ground stems of Ryania
speciosa, a native plant of tropical America. The principle alkaloid in this
stem extract is ryanodine which makes up 0.16-0.2% of the product. Ryania is
highly toxic to the fruit moth, coddling moth and corn earworm, European corn
borer, and citrus thrips, but it is ineffective against the cabbage maggot,
cauliflower worms or boll weevil.
Ryania is a general use pesticide.
Ryania has a very low toxicity to mammals and is labeled with the CAUTION
signal word. At high doses it affects muscles, preventing contractions and
resulting in paralysis (9). Symptoms of poisoning include vomiting, weakness
and diarrhea. Rigidity of the muscles and depression of the central nervous
system can lead to a coma and to death.
The rat oral LD50 is 1,200 mg/kg and guinea pigs have an oral LD50 of
2,500 mg/kg and rabbits have 650 mg/kg LD50. Dogs are much more susceptible
with an LD50 of 150 mg/kg. The estimated lowest lethal dose for man is 143
mg/kg. The pure ryanodine alkaloid is 500 to 700 times more toxic than the
crude powder. A 2-5 mg/kg dose of ryanodine elicited symptoms in the frog and
mouse (4). The dermal LD50 for rats is above 2,000 mg/kg. No information is
available on inhalation toxicity.
Rats and guinea pigs were fed diets containing 1% ryania powder for at
least six months and showed no symptoms. Rats fed 5% diets had weight loss
and some deaths within 25 days (4).
No data was available.
Large doses of ryania powder (around 1,500 mg/kg/day) in the diets of
rats produced hemorrhages in the pancreas and intestines. It also produced
lung complications in the test animals (10).
Fate in Humans and Animals
Single sublethal doses given directly into the vein produced slowly
developing high blood pressure in experimental animals (1). Residues of 6 ppm
on apples were harmless to laboratory animals.
Chickens fed for six months on diets of 1% ryania showed no symptoms and
did not have any evidence of cumulative effects (4). Ryania is moderately
toxic to birds and wildfowl. Some LD50 values include: wild birds 1.78
mg/kg; pigeons 2.31 mg/kg; and quail 13.3 mg/kg (8). It is considered
moderately toxic to fish also. The 96-hour LC50 for rainbow trout is 3.2 mg/l
and 18.5 mg/l for bluegill.
The toxicologically active portion of ryania, ryanodine, is water soluble
but stable during storage and stable upon exposure to light. Ryanodine is not
considered to be poisonous to plants (4).
The major degradation product of ryanodine is anhydroxyanodine (6).
201 Center St
Stockertown, PA 18083
Review by Basic Manufacturer:
Comments solicited: May, 1992
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