126 



usual, and this remiuds us of an occurreuco wliich shows how careful 

 one must be in drawing conclusions from experiments to destroy in- 

 sects. Counting upon the ordinary appearance of the Elm Leaf-beetle, 

 we sprayed the trees in our garden with London purple early in the 

 summer, and as no damage was done, we were quite of the opinion that 

 the spraying had been a success until, later, we noticed that uiisprayed 

 trees were quite free also. In the same way a gentleman came to us 

 toward the end of the season and informed us that he had completely 

 protected his trees, by spraying the grass under them with Paris green, 

 his trees for the first time in several years having retained the verdure 

 of their foliage. 



SOME RECENT ENTOMOLOGICAL MATTERS OF INTERNATIONAL 



CONCERN.* 



Entomology is one of the most fascinating branches of natural history, 

 but its devotees find such a vast number of species to deal with (very 

 many yet unstudied) that their work is for the most part somewhat ex- 

 clusive and interests few but the specialist. In truth, though so impor- 

 tant in the economy of nature and in their relations to man, insects are 

 yet too often looked upon as rather unworthy his serious thought. 



l!^evertheless there are many insects which possess general interest 

 by virtue of the manner in which they affect man directly or indirectly. 

 Among such may be mentioned species which prevail in several differ- 

 ent parts of the world, and the interest is enhanced if they affect man's 

 comfort and convenience, or are injurious to agriculture or horticulture. 

 It is my intention this evening to refer to three of the latter class, which 

 have lately become rather notorious. 



In doing so I omit extended consideration of the methods that recent 

 investigation have shown to be most efficient in enabling the cultivator 

 to contend with and control these enemies to agriculture; for, though 

 this practical bearing of the subject is of immense importance to the 

 people concerned, I take it that none of those in my hearing are prac- 

 tically interested. 



THE lOERYA OR FLUTED SCALE. 



The first is what I call the Icerya or Fluted Scale {Icerya purchasi 

 Maskell). It is one of our largest scale-insects (family Coceidce), and 

 has of late years done immense injury to the orange groves and to 

 many other trees and shrubs of southern California. The history of 

 the species is interesting, and points to Australia as its original home 

 and to its introduction from Australia to New Zealand, Cape Town, 

 South Africa, and California. Nothing was known or published upon 



* Read by C. V. Riley before the Philosophical Society of Washington, D. C, March 

 31, 1838, and illustrated by diagrams. 



