The Canadian Horticulturist. 



39 



eggs upon the outside of the apple 

 at the l)lossoni end, in such a way 

 that the young larva- when eating its 

 way into the apple is liable to be 

 poisoned, if poison has been sprayed 

 upon the tree. 



Notwithstanding this important 

 difference in the habits of the insects, 

 certain fruit-growers claimed that 

 equally good results followed the 

 spraying of plum-trees as in spray- 

 ing apple-trees. At last the matter 

 has been made the subject of careful 

 experiment by Mr. C. M. Weed, the 

 ICntomologist of the Ohio State Ex- 

 periment Station. The results of 

 Mr. Weed's experiments are very 

 striking. They seem to show, so far 

 as the results of a single season's 

 work with a single variety of clierries 

 can be relied upon, " that three- 

 fourths of the cherries liable to mjury 

 by the Plum Curculio can be saved 

 by two or three applications of Lon- 

 don purple in a water spray (in the 

 proportion of one ounce to five gal- 

 lons of water) made soon after the 

 blossoms fall." 



No explanation is made by Mr. 

 Weed as to the way in which the 

 poison acts, - — whether the adult 

 beetles are destrojed before they lay 

 their eggs, or whether the poison 

 reaches the larvae. During the 

 present season we have made some 

 observations and conducted an ex- 

 periment which indicate that the for- 

 mer is the case. 



During the latter part of the past 

 summer my attention was attracted 

 to a serious injury to the fruit in an 

 apple-orchard through which I pas- 

 sed daily. A large proportion of the 

 apples in one corner of the orchard 

 had been eaten into by something 

 which made small pits from one- 

 eighth to one-fourth inch in diameter, 

 and of about the same depth. On 

 one tree nearly every apple had been 

 attacked, and in many cases there were 

 ten to twelve holes in a single apple. 

 The injury was so serious as to ren- 

 der the fruit on this part of the 

 orchard unmarketable. 



The holes in the apples were first 



observed during the latter part of 

 August. At that time many of them 

 were partially grown over, while 

 others were fresh, indicating that the 

 pest had been at work for a consider- 

 able time and was still active. As 

 the injury to the apples resembles 

 somewhat that caused by Lithophane 

 nntennatn, a climl)ing cut-worm, that 

 sometimes infests apples in Western 

 New York, I at first searched for 

 caterpillars and gave little thought 

 to the Plum Curculios that 1 fre- 

 quentl}' found hiding in the holes in 

 the apples. But after finding a con- 

 siderable number of these insects in 

 these pits, it occurred to me that 

 they might be the cause of the mis- 

 chief. Several perfect apples were 

 then selected and placed in breeding 

 cages, in each of which were confined 

 several curculios. The question was 

 soon settled : within twenty-four 

 hours the beetles had begun to eat 

 into the apples. They made small 

 holes at first, but these were soon 

 enlarged so as to form pits of the 

 size indicated above. We thus see 

 that the Plum Curculio is a voracious 

 feeder, and conclude that the spray- 

 ing of the plum-trees early in the 

 season with Paris-green water pro- 

 tects the fruit by the destruction of 

 the adult curculios before they have 

 laid their eggs. 



Since preparing the above I have 

 received the following note from Mr. 

 Weed, for publication in a journal 

 of which I am Entomological Editor. 

 I take the liberty of publishing it 

 here in advance of its appearance in 

 that place, as it confirms my con- 

 clusions. 



"In referring to some experiments 

 made by me to prevent curculio 

 injuries, in the August number of the 

 Anicricnn Nnfiirnlisf, the question is 

 raised as to how spraying with poi- 

 sons may have a preventive effect 

 on this insect. I believe that satis- 

 factory explanation may now l">e 

 given. Early last June 1 confined 

 an adult Plum Curculio in a jar with 

 a large green plum, and was surprised 

 at the avidity with which the fruit 



