Plant Diseases and Insects. 



6 3 



other trees — about seventy-five in number — and also the 

 shrubs and plants growing in Mr. Wolf skill's yard, have been 

 practically cleared of iceryas by these lady-birds, and the 

 latter have of their own accord spread to the adjoining trees 

 to a distance of fully three-fourths of a mile from the original 

 tree. 



""Besides the three consignments of these lady-birds re- 

 ferred to above, I also received two later consignments. The 

 first of these reached me February 21st, and numbered thirty- 

 five specimens ; these I colonized on an icerya-inf ested orange 

 tree in the large orange grove belonging to Colonel J. R. Dob- 

 bins, of San Gabriel. The last consignment of three hundred 

 and fifty specimens arrived March 20th ; one-third of these I 

 left with Colonel Dobbins, while the remainder I colonized on 

 orange trees in the extensive grove owned by Messrs. A. B. 

 and A. Scott Chapman, in the San Gabriel Valley. All of 

 these colonies have thrived exceedingly well." 



Professor Henry speaks* in unqualified praise of the suc- 

 cess of this enterprise, and entertains great hope for the de- 

 struction of the scale. "Without doubt it is the best stroke 

 ever made by the Agricultural Department at Washington. 

 Doubtless other efforts have been productive of greater good, 

 but they were of such character that the people could not 

 clearly see and appreciate the benefits, so that the Department 

 did not receive the credit it deserved. Here is the finest 

 illustration possible of the value of the Department to give 

 people aid in time of distress. And the distress was very 

 great indeed ; of all scale pests, the white scale seems the 

 most difficult to cope with, and had no remedy been found it 

 would probably have destroyed the citrus industry of the 

 state, for its spreading to every grove would probably be only 

 a matter of time. ' ' 



3. Ar seniles for the Plum Curculio. 



One of the most important results of the year is the obtain- 

 ing of undoubted proof of the efficiency of arsenical spray in 

 checking the ravages of the curculio upon stone fruits. The 

 question has been stubbornly argued on both sides, and it is a 

 noteworthy fact that growers, rather than entomologists or ex- 



*Insect Life, ii. 141. 



