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The East Mailing Research Station (lll )of Kent, England, in 133U 
stated that a single application of a derris spray of known rotenone content 
is adeouate for control of the raspberry and loganterry "beetle. 
Steer ( 3^9) in 193^ reported experiments on the control of the 
raspberry and loganberry hefetle in Kent, England. Tests were made with 
derris (2.71 percent of crude rotenone or 2.32 percent of recrystallized 
rotenone) as a spray and as a dust, and cube (6.26 percent of crude roten- 
one and. 5.27 percent of recrystallized rotenone) as a spray. In the sprays 
2 pounds of derris or 1 pound of cube, plus 5 pounds soft soap, was used 
per 100 imperial gallons. The dust was made by mixing 3,7 percent of 
derris and 96.3 percent of china clay. The ccnclusions are as followsJ 
Derris dusting. Good results have been obtained by 
dusting three tines with a derris dust of 0,09 pf^rcent 
rotenone content applied to kill the beetle larvae. This 
method of control is somewhat less effective than a single 
wet spraying given when the larvae begin to attack the 
fruit, It is more costly, and the dust is very apt to 
leave an unsightly (though harmless) deposit on the earlier 
berries. On the othfr hand, a dust is Quickly and easily 
applied and for this reason recom-nends itself to many growers. 
An attempt to kill the adults, and to prevent egg 
laying and subsequent fruit damage, by means of a single 
application of dust was not successful. Thi^ experiment 
cannot, however, be regarded as conclusive in vie^^r of the 
good results obtained by Pethrrbridge and Thomas, who 
dusted loganberries in a similar manner. To get adeouate 
control by means •f a dust applied sufficiently early to 
avoid leaving a dr-posit on the fruit, and intended for the 
adult beetles rather than the larvae, it may be necessary 
to dust very heavily and to use a dust of higher rotenone 
content than that hitherto used in our cxoeri^ents. 
Wrt spraying with derris. From the results of field 
spraying trials carried out to date at East Mailing, it is 
clear that one application of derris and soap is adequate 
for either raspberries or loganberries. This should be 
given when the larvae begin to damage the berries. 
. The results obtained on blackberries suggest that 
the very early varieties can be given exactly the same 
treatment as loganberries. 
At the concentrations use d no differences can be 
detected between 'the performances of derris and of cube 
either at any one time during the picking season or for 
the whole period. 
Reark ( 327 ) In I938 , in comparing the insecticidal values of 
derris and cube, referred to this report by Steer, 
