84 



grounds of Mr. Timothy Hopkins at Menlo Park, and in the grounds 

 of the Hotel del Monte, on the Bay of Monterey. Small, close canvas 

 tents have been put around the trunks of the trees, and in these tents 

 hydrocyanic acid has been used. This gas readily penetrates the bur- 

 rows of Dendroctonus and kills practically all of the larvse and adults 

 in the burrows. As many as 300 larvse have been found in a vertical 

 length of 3 feet of trunk, and all of these larva? have been killed ])y 

 the gas. Such a procedure is, of course, not at all practicabhi in fight- 

 ing Dendroctonus in forests, but seems to offer a means of killing the 

 pest when attacking a few clioice trees, as is the condition in the parks 

 and grounds in the neighborhood of the university. 



PLANT ENVIRONMENT AND INSECT DEPREDATIONS. 



By F. William Rank, Diirhdm, N. H. 



We are constantly learning something new about the relationship 

 between insect and plant life. A new species hitherto unknown is 

 discovered, and slioi'tly it may be this insect lays claim to some of our 

 domesticated plants, and thereafter continues to menace or prey upon 

 it as commonly as though this had ever been its custom. Again, spe- 

 cies that we have long known for some reason change their appetites, 

 or rather enlarge upon their food suppl}^ so as to include in their 

 menu plants heretofore not cared for. Such events are constantl}^ 

 taking place, and entoniologists are ever ready to make new observa- 

 tions. To find an old friend taking a meal on a heretofore strange 

 plant is noted with interest. Although experience has shown that 

 these simple observations may not indicate much, yet they are impor- 

 tant, for as time goes on conditions may arise wherein this indicated 

 outbreak may occur. 



Economic entomology has come to be a great factor in America, and, 

 with an ever-increasing number of keen observers everywhere through- 

 out our broad land, little happens that is not soon brought to the 

 notice of someone. 



The gardener, fruit grower, or farmer that is awake to his calling 

 has a remedy or suggestion at his bidding for most of his insect foes. 

 These remedies are generally looked to by him as cure-alls, and if the 

 insects are only destroyed everything is lovely. 



The point that I desire to emphasize in this paper is that simple 

 remedies for insect depredations in man}^ cases are not after all what 

 really is needed. It was not many years ago that everyone had his 

 own remedy for certain insect depredations, and each man that made 

 a success attributed it to his particulai treatment. Modern investiga- 

 tion, howev^er, exposes many of these practices as absolutely imprac- 



