PLUMS AND PLUM CULTURE IN MICHIGAN. 239 



Oue of the oldest remedies, and the one that to-day, doubtless, commands a 

 greater degree of confidence than any, if not all others, is that known as the 

 "jarring process," consisting of the jarring down of the insects upon a cloth 

 spread out for that purpose, and the gathering up of the insects, together with 

 the punctured and fallen fruit, and destroying them. Indeed, this may with 

 propriety be said to be the only remedy that, when thoroughly and efficiently 

 applied, is sure to be always successful. To succeed with this, however, it 

 must be repeated one, two, or even three times a day (according to the state of 

 the weather and the numbers and persistence of the enemy), and must be com- 

 menced as soon as the fruits shall have swelled sufficiently to burst the 

 remains of the calyx enclosing them, and thus become exposed to the attack 

 of the enemy, and continued till his final disappearance, which will probably 

 not be until the fruit is nearly of full size. Merely shaking the tree will not 

 suffice. The insect will only yield, with certainty, to a sudden jar, such as 

 would be given by a blow upon the trunk or the stump of a shoot, with a 

 hammer or mallet. Such implement should always be carefully padded if 

 intended to be used directly upon the bark of the tree, to avoid injury from 

 bruising. 



Soma years since the horticultural public were elated with the announce- 

 ment that Mr. Eansom, of St. Joseph, in this State, had discovered a means of 

 trapping the curculio, by smoothing and compacting the earth about the base 

 of the tree, and placing there chips or other similar articles, under which the 

 insect would take shelter, at night, and could be taken up in the early morn- 

 ing and destroyed ; but alas ! it was also soon discovered that the " Little 

 Turk" refused to accept these seductive but treacherous temptations, as soon 

 as the warmth of the advancing season sufficed to enable him to bear the night 

 temperature. Still, while these traps are efiective, they greatly economize 

 labor, and it is understood that some of the best practitioners employ them in 

 connection with the jarring process. 



DR. hull's experiments. 



We close the consideration of the modes of contesting the ground with the 

 curculio, with an extract from the Horticulturist for November, 1874, at page 

 337; which gives some accounts of the experiments of Dr. Hull of Alton, 

 Illinois, stating that, from 1,930 trees, he, this year, captured not less than 

 153,000 curculios. In a statement before the Alton Horticultural Society, the 

 doctor says : 



"Early in the season I commenced a series of experiments to determine, if 

 possible, at what particular period of the day curculios were at rest. On three 

 different days I dropped a number of curculios in flour, and near sundown of 

 each day put them in the forks of the trees and watched them until they 

 crawled in to some place of concealment, which was usually in the crevices of the 

 rough bark, and into depressed parts made by cutting off limbs of trees. Out- 

 of 30 insects thus watched to places of rest all concealed themselves as stated, 

 except oue, which went to the ground and crawled under a clod of earth. Out 

 of 30 insects thus watched, all but one were found early the following morning 

 just where they went to rest at night. 



"Again, I made other tests with marked insects by placing them on the trees 

 in the morning. This experiment was repeated on three successive days, em- 

 ploying 30 insects each day. Near sunset the trees were thoroughly jarred 

 over a curculio-catcher. This experiment resulted in the capture of 27 of the 



