1891.] Entomology. 69 
same region, and presumably in the same orchard, the next year, by 
Mr. C. P, Gillette, showed that ten times as much injury was done by 
the Gouger as by the Curculio. Consequently, so far as the Curculio is 
concerned, this experiment might well have been left out of the record. 
In 1889 Mr. C. P. Gillette made some careful experiments on native 
varieties of plums at the Iowa Experiment Station, apparently on the 
same orchard that Professor Osborn had worked in the year before. 
Mr. Gillette recognized the dangers of the every-other-tree method, 
making a distinct statement of the principles involved, in the Bulletin 
of the Iowa Expériment Station for May, 1890 (pp. 383-384), shortly 
after the publication of my letter in Agricultural Science, which, how- 
ever, he had probably not seen when his article was written. The 
percentage of Curculio injury on both sprayed and unsprayed trees 
was extremely small, though ‘“‘ the indicated saving of fruit that would 
have been injured in the absence of treatment was forty-four per cent.” 
In this experiment only two sprayings were made, and, as the author 
States, both were too-early to take most effect upon the Curculio. 
The conclusions concerning the Curculio reached by Professor 
Forbes, in his admirable experiments in spraying apples for the Cod- 
ling Moth, have frequently been quoted to show that the benefit to be 
derived from spraying for the insect is much less than in the case of 
the Codling Moth. But, aside from the fact that in these experiments 
the injuries of the Apple Curculio (Anthonomus quadrigibbus) and the 
Plum Curculio are not separated,—which alone would vitiate the con- 
clusions so far as they relate to the latter insect,—a few trees were 
Sprayed in the midst of others untreated, so that, from the principle 
already stated, results of little value, so far as the Plum Curculio is 
concerned, could be expected. 
In 1887 Mr. W. B. Alwood made some experiments on the grounds 
of the Ohio Experiment Station, on the strength of which he has fre- 
quently claimed priority in demonstrating the usefulness of the arsen- 
ites as Curculio destroyers. No record of them was published until 
1889, when they were incorporated in Dr. Riley’s American Pomo- 
gical Society article, and also in the Riley-Howard memoir in the 
Department of Agriculture Report for 1888 (pp. 70-71). Three plum 
trees of the Green Gage variety were treated in the midst of about 
twenty-five untreated trees of four other varieties. One Green Gage 
was left as a check. Paris green, at the rate of one pound to fifty gal- 
lons of water, was applied May 13th and 17th. Of course two such 
Strong applications, only four days apart, greatly injured the foliage, 
So that “ fully fifty per cent. fell off.” Mr. Alwood continues: 
