514 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



will result in information which will permit of the propagation in 

 numbers of these beneficial forms and which will also contribute to 

 their more ready establishment in orchards. 



INSECTICIDE INVESTIGATIONS. 



Laboratory and field experiments have been continued with various 

 insecticides, especially lime and sulphur preparations, several arseni- 

 cals and other toxic substances as possible substitutes for these, 

 nicotine S])rays, distillate emulsions, etc. 



It has appeared that recommendations as to the amount in propor- 

 tion to water of a given arsenical, as arsenate of lead, which should 

 be used in sprays in the control of certain important pests, are more 

 or less arbitrary and not based on sufficient experimental work. On 

 account of the present large annual use of arsenical sprays, it is very 

 important to know the minimum amount of arsenic required to con- 

 trol a given insect satisfactorily, thus avoiding the waste resulting 

 from the use of an unnecessarily large amount. Some experiments 

 have therefore been undertaken to determine as exactly as possible 

 the quantity of arsenate of lead which should be employed satisfac- 

 torily to control the codling moth and plum curculio on apples and 

 peaches. The experiments cover the use of arsenate of lead at 

 strengths ranging from one-half pound to 5 or 6 pounds per 50 

 gallons of water. 



CEREAL AND FORAGE PLANT INSECT IN\'EST1GATI0NS. 



The cereal and forage plant insect investigations, carried on under 

 the immediate direction of Mr. F. M. Webster, have shown good 

 results and have opened up several new problems of importance. 



WOEK ON THE SO-CALLED GREEN BUG. 



A threatened outbreak of the so-called green bug demanded atten- 

 tion from a number of members of the force. The manuscript for 

 a bulletin on this pest has been completed and now awaits publica- 

 tion. In future it will be necessary to keep the whole southwestern 

 country under continued surveillance in the fall in order to be able 

 to warn farmers of impending danger from this pest. 



WOEK ON THE JOINTWORM. 



Work on the jointworm has been continued. The damage caused 

 by the insect was less in Ohio and Indiana than during the two pre- 

 vious years, probably due to the attacks upon it of the predaceous 

 mite Pediculoides ventricosus. As indicating the excessive abund- 

 ance of this mite in some parts of the country. Dr. Jay F. Scham- 

 berg, a leading dermatologist of Philadelphia, Pa., reported that — 



In August, 1010, the National Guard of Pennsylvania was encamped at Get- 

 tysburg in a tt'heat field opposite the battle field of Gettysburg. The Third 

 Regiment of Pennsylvania used straw in the soldiers' sleeping bags. About 

 300 men were attacked with grain itch. This information was received from 

 Dr. Luhurg, of Philadelphia, assistant surgeon of the regiment. The First 

 Heginiont, which was encamped close by, had straw supplied to it, but Dr. 

 Turnbill, the surgeon, would not permit it to-be used. Some few cases of grain 

 itch developed among the men of this regiment. The straw was reported as 

 received from a source in Gettysburg. 



