192 THE PLUM CURCULIO. 
Taste XCIY.—Results of spraying apples for plum and apple curculios in Illinois, 1904. 
Total 
Plat Total | number P Sacer 
ye Treatment. Trees. | number | of fruits Seen 
2 of fruits. | punc- frit 
perl ruit. 
Deccc 3 applications Bordeaux mixture and (aris green (check) . 13 10,185 7, 617 25. 21 
II....] 10 applications Paris green, $ pound to 50 gallons water --. - 14 14, 352 7,931 44.74 
III...| 16 applications Paris green, 4 pound to 50 gallons water... 13 10, 861 4,118 62. 08 
IV...| 8 applications Paris green, 4 pound to 50 gallons water .... 15 12735 7,066 44. 52 
Vi l_.|\7 applieations arsenitelonlimes-2 a ecee eee ee eenee eee 13 11, 592 6,321 45. 47 
VI... 7 applications/arsenate of lead! <2. --.22- 2222. 522252--2-- 12 13,197 7,310 44. 61 
All of the plats, including the check (Plat I), were sprayed three 
times with Bordeaux mixture and Paris green, one-fourth pound to 50 
gallons of the Bordeaux, to protect from apple scab and the codling 
moth, and three sprayings on the checks reduced curculio injury, 
as shown by other trees in the orchard entirely unsprayed, 15.21 per 
cent. The marked influence of seasonal and local conditions on 
curculio injury is very forcibly shown in the Illinois results. The 
treatments in 1903 showed no benefit as regards control of the insect, 
whereas in another orchard in 1904 the saving in fruit from trees 
liable to injury ranged from 27.65 per cent to 54.53 per cent. Prof. 
Crandall states: 
To sum up the matter of spraying for the curculio from the standpoint of results 
obtained during the two seasons of 1903 and 1904, it seems possible that under favorable 
conditions and with a reasonable number of applications to control curculios to the 
extent of from 20 to 40 per cent of the possible injury. There is benefit to be derived 
from spraying but not that degree of benefit which would warrant commendation of 
spraying as the one great panacea of injury done by the curculio. 
In the proceedings of the Illinois Horticultural Society for the 
year 1904 (p. 91) Dr. Forbes, in continuation of his study of the- 
curculio in Illinois apple orchards begun in 1901, reports results of 
experiments with arsenical sprays carried out in Southern Illinois 
and independent of the researches of Prof. Crandall, just alluded to. 
Four plats were established, including the check, and 4, 6, and 8 
applications of arsenate of lead were given, beginning May 6 to 10, when 
the trees were in first full bloom, and repeated at intervals of about 
10 days, ending July 28. Prof. Forbes presents the figures of yield 
of sound and injured fruit, though the experiment loses some of: 
its value for the reason that the trees were of different varieties and 
the plats not all under the same conditions, being located in three 
different orchards, although all were on the same farm. Prof. 
Forbes summarizes as follows: 
Finally, to sum up in a word the most important practical results of the orchard 
experiment with arsenate of lead, we may say that four sprayings, apple trees of old 
varieties exposed to a very heavy attack by the plum curculio, the first spraying 
applied in early May just as the trees were coming into bloom and the others at intervals 
of 10 days thereafter, the whole operations costing 17 cents per tree, may be expected 
