-74- 
OXYDENDRUM ARBOREUM (L.) DC. Sourwood. 
Extraots were not repellent to the Japanese beetle.— Metzger and 
Grant (277). 
PTERIS JAPONICA (Thunb*) D. Don. Asebo, asemi, etc. 
This plant is known by at least 38 common names. It was first 
desoribed by Kraempfer in 1712 under the names "asjebo (asebo)" and 
•asjend (asemi) . n It is very common in all the mountainous regions of 
Japan and has been used for a long time as an insecticide. One employs, 
according to the circumstances, a decoction of fresh leaves (150 gm. 
of ground leaves per liter of water) 9 dried leaves (30 gm. per liter), 
or dried branches with leaves (70 gm. per liter). The mixture is 
boiled for 45 to 60 minutes, and when it is ready to be used the first 
is diluted 10 times, the second once, and the third twice.— Motte ( 288 ) . 
RHODODENDRON HUNNEWELLIANUK Rehder & Wilson. Nao-yang-wha. 
This plant grows in China, and the compounds (andromedotoxine and 
an unidentified substance) present in it are effective as insecticides. 
Preparations made from this plant paralyzed the insects, the injury 
spreading from the posterior to the anterior end. It is recommended 
especially as a stomach poison, end three formulas are fiven.-- 
Ku (237). 
This species crows wild in the Yangtze River rep-ion in China and 
is used there as a stomach poison for insects. The flowers are supposed 
to be the most valuable, but in recent tests extracts of the flowers 
had no value against aphids as a contact poison.— Shepard (363 , p. 299). 
RHODODENDRON JAPONICUM (Gray) Suring. Synonym: R. molle Sieb. & Zucc. 
The powdered flowers might be used to good advantage to control 
the mulberry white caterpillar (Rondotia menciana Moore) in China.— 
Scar one (353 ). 
RHODODENDRON MOLLE (Bl.) G. Don. Synonym: R. sinense Sw. Sheep poison. 
This 6peoies has been found effective against certain insects in 
China.— Chiu (94) • 
The dried and ground flowers were oommonly sold by Chinese drug 
stores because of their effectiveness against bugs and maggots. In 1935, 
18,000 plants of this species were collected and transplanted on the 
Bureau farm in China. In field tests against the adults of cabbage leaf 
beetles, Colaphellus bowringi (3aly)# the following mortalities were 
obtained with the powdered flowers: In soap solution 96, alcoholic ex- 
tract in soap solution 92, in kerosene emulsion Plj as compared with 
pyrethrum in soap solution 98.--China National Agricultural Research 
Bureau (92). 
