10 SIXTH ANNUAL REPORT 



tures : whether, in other words, the worm belongs to the first or second 

 broods. Careful notes, covering such contingencies, are very neces- 

 sary to any just estimate of how many worms leave the fruit by means 

 of a web or by crawling down the trunk during night, before said 

 fruit falls ; and i't is doubtful whether any broad generalizations on 

 the subject can be made. Dr. LeBaron estimates that about half the 

 worms thus leave. Hence all systems confined to destroying the fallen 

 fruit are but half-ways toward complete destruction of the worms, 

 and do not compare well, in efficiency, with the bandage remedies. 

 In pear culture they would be of still less value. The result of Mr. 

 Parker Earle's large experience in growing this fruit at South Pass, 

 Ills., in respect of this insect is : 1st. That infested pears hang on the 

 tree after the exit of the worm. 2d. That though they always show 

 the frass before said exit, they do not readily drop from the tree when 

 jarred. 3d. That they are mostly injured by the second brood of 

 worms. 



Dr. LeBaron's experience with the Wier trap is similar to my own. 

 Respecting the time to appl}', and method of using the bandages, his 

 advice is essentially that which I have given, but preferable in that it 

 points out the least possible labor necessary. He recommends (for 

 N. Illinois) that the bandages be in place a month after the bloom- 

 ing of the trees; that the first examinati(m be made seven weeks after 

 the blossoms have fallen ; that three subsequent examinations be 

 made, at intervals of twelve days, and one final one at the end of the 

 season. The soundness of the advice will appear by the light of the 

 facts recorded in previous reports respecting the time required for the 

 complete development of individuals of the different broods; and to 

 make it apply to the latitude of St. Louis, I would say : let the first 

 examination be made not later than si;e weeks after the falling of the 

 blossoms; and that four subsequent examinations, at intervals of 

 twelve days, be made between it and the final one in the fall, which 

 may be deferred till all the apples are gathered. 



Another point brought out by Dr. LeBaron is the fact, which lean 

 corroborate, that though two worms may often be found in the same 

 apple, they are generally, if not always, of difl'erent size ; thus strongly 

 indicating that they are from difl'erent parents, and that the same moth 

 in a state of nature never lays more than one egg on each apple, 

 though the rule does not hold good in a state of confinement."^ 



The insect is spreading over the western country which has hith- 

 erto been blessed by its absence, and is now working in the orchards 

 of Utah, which had, up to within a year or so, enjoyed immunity from 

 its attacks. 



*See 3d Rep., \>. 1(12. 



