62 

 The next paper was presented by Mr. Burgess : 



NOTES ON ECONOMIC INSECTS FOR THE YEAR 1903. 



By A. F. Burgess, Co lumbus, Ohio. 



In general in may be said that few serious outbreaks of destructive 

 insects have appeared in Ohio during the past year. The chinch bug 

 (BUssus leucopterus) and the Hessian fly ( Cecidomyia destructor), two 

 of the prime agricultural pests of the State, have caused little damage. 

 One of the reasons for the disappearance of the latter is probably due 

 to the fact that farmers are learning to sow their wheat late enough 

 in the fall to escape the second brood of this insect. 



During June and July great damage was caused to apple stock in 

 the nurseries in the northeastern part of the State by the apple aphis 

 {Aphis mali), and where no effort was made to control this insect 

 many small trees were ruined. I have also been informed that the 

 same conditions prevailed in New York, especially in the vicinity of 

 Geneva. One of the leading nursery firms near Painesville, Ohio, 

 tried many different remedies, but the best results were obtained by 

 dipping the tops of the young trees in a wash made of whale-oil soap, 

 tobacco extract, and water. This was prepared by dissolving 1 gal- 

 lon of whale-oil soap in 50 gallons of water and adding 1 gallon of 

 tobacco extract to each 75 gallons of this mixture. The tobacco 

 extract was purchased from a firm in Louisville, Ky. Continuous 

 applications were necessar} 7 in order to control the insect, but by fol- 

 lowing up this treatment serious injury to the trees was prevented. 

 The leaves of birch trees growing in this region were also attacked 

 by an undetermined species of aphis and many were seriously injured. 



In other sections of the State, particularly in the nurseries where a 

 careful examination of existing conditions was made during the sum- 

 mer, no unusual abundance of aphides was noted. 



The reports of the Weather Bureau show that the rainfall for north- 

 eastern Ohio for the period from the middle of May until early in 

 July was several inches above, and the temperature was considerably 

 below, the normal for this region. These conditions were undoubt- 

 edly favorable for the reproduction of this insect and proportionally 

 unfavorable for the increase of its parasitic and predaceous enemies, 

 and as there was a good supply of overwintered eggs an outbreak 

 was inevitable. 



On August 24 Mr. E. C. Cotton, one of my assistants, while inspect- 

 ing a nursery near Bucyrus, found that the roots in a block of 1-year- 

 old apple seedlings were being eaten by a white grub (Lachnostema 

 sp.?) to such an extent that some of the trees were dying. The land 

 had been in corn the previous year, and as the nursery stock was kept 

 free from grass and weeds it was evident that the insects were forced 

 to attack the small roots on account of lack of food. The outer tissue 



