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The destruction 9f the rasp'berry bef'tle "by derris in the Nether- 
lands was general practice in 193^, according to the Kolonlaal Instituut 
ef Amsterdam (12, Y^) , 
One of the principal usep of derris in the Netherlands is for the 
control of the rasp'berry beetle. — Van der Laan ( 2U3 ) in 1936» 
Steer ( 360 ) in 193^ published a surpmary of the use of derris as 
an insecticide in England. For many years, usually under various propri- 
etary names, derris root has been used in England, not only as a spray 
for fruit trees, hops, and garden crop? but as an ingredient of cattle 
and sheep washes and domestic-insect powders. There are four forms in 
ccmmon use: (l) The finely ground root, for use with soap or other wetter; 
(2) the ground root ready mixed with dried soap or other wetter and re- 
quiring merely the addition of water; (3) an extract of the root, usually 
in an emulsified f«*rm, ready for dilution with water; and (^) the ground 
root mixed with a suitable "carrier" or "filler','" such as china clay, and 
intended for application as a dusting powder. Derris powder costs from 
50 to 62 cents per pound. Dusting powders cohtaining 0.2 percent of roten- 
pne uavLally cost about 7 cents per pound. Derris is compatible with any 
of the eprays in common use, such as bordeaux mixture and lime-sulfur. 
At East Mailing Research Station derris was first used experimentally in 
1928 to control the larvae of the raspberry beetle. Against the raspberry 
"beetle a single spraying of derris and soap gives perfectly satisfactory 
results. l>lany growers prefer to attack the adult sta^-e of the peat by 
means of derris dusts and so prevent egg laying and subsequent fruit damag'^. 
Good results are obtained by dusting diiring the flovrering pc-riod, but 
several applications of the dust seem to be reouircd. 
Derris gives good results. — Anonymous (2) in l^^T. 
Kearns and Marsh ( 23?) in 19.'^7 recommended derris dust for the con- 
trol of adults of the raspberry beetle and derris dust or spray for the 
larvae. The derris dust should contain not les^ than O.IS percent, and 
the spray not less than O.OOU percent of crystalline rotenone. Many samples 
of derris root contain 1,5 percent of crystalline rotenone, and with a root 
f»f this concentration it is necessary to use 2-1/2 pounds of derris root 
per 100 imperial gallons of watrr. The application after petal fall is the 
more important, and a spray is preferable to a dust, as it also provides a 
control of aphids. For loganberry and blackberry a program similar to that 
for raspberry is recommended. 
Warv/ick ( Uip ) in June 193^, reported that two dustings with derris 
are usually adequate to control the raspbe-^rry and loganberry beetle. 
Shaw ( 337 ) in January 1939, wrot" that the Tiixed dcrris-cop-oer- 
oxychloride wash vras likely to become recognized in Great Britain as the 
standard combined treatment for the raspberry beetle and cane spot, 
Byturus unicolor Say, a raspberry fruitworm 
Caffrey (§V) in April 19;^5, recommended derris sprays and dusts 
for the control of 3. unicolor . If sprays are used, the first spray applied 
just before the blossoms open should consist of a mixture of ^ pounds cf 
lead arsenate powder and U pounds of hydmted lime tr 100 gallons of wat'^r. 
