1896.] ENTOMOLOGICAL NEWS. 307 



DEPARTMENT OF EGONOMIG ENTOMOLOGY. 



Edited by Prof. JOHN B. SMITH, ScD., New Brunswick, N. J. 



Papers for this department are solicited. They should be sent to the editor, Prof. John 

 B. Smith, Sc.D., New Brunswick, N.J. 



(Continued from page 272.) 



Proceedings of the Association of Economic Entomologists.— Saturday, 



August 22, morning session. — Mr. Smith spoke of the results of his trip 

 to California to investigate the insect enemies of the San Jose scale with 

 the view of introducing them into New Jersey. Mr. Smith finds that the 

 work of predaceous insects has been very much over-estimated in Cali- 

 fornia, and that particularly the Australian beetles had been credited with 

 work that there is no evidence that they ever accomplished. As against 

 the San Josd scale the Australian insects have been of no value whatever. 

 Combined with climatic condition the scale has been reduced to harmless 

 number in Southern California by Chilocorus bivulnerus and Aphelinus 

 fiiscipennis. In Northern California the scale is being kept under by 

 systematic spraying. Of all the species introduced into California by 

 Mr. Koebele, one only, excepting the Vedalia seems to have increased 

 sufficiently to be useful, and this, Rhizobius ventralis, has obtained a 

 permanent foothold thus far in only two counties of the State. He does 

 not believe in the possibility of this insect controlling the black scale, and 

 it certainly has not done so up to the present time. 



Mr. A. D. Hopkins read a paper on " Insects Enemies of Trees." An 

 elaborate series of experiments is now being carried on at the West Vir- 

 ginia Station to learn the best time for felling trees, so as to secure total 

 or partial immunity from insect attack. A special insectary has been con- 

 structed for this purpose, and a box for each month has been provided 

 for a considerable number of trees. In these boxes are placed twigs, 

 branches and sections of trunk in order that whatever insects may be upon 

 the trees at the time may be determmed. Hickory cut in Winter is always 

 seriously injured by Lyctus striatus. When cut in July or August, it is 

 not injured by this insect, nor is it attacked by Scolytids. The period 

 when trees may be cut with least danger is not the same for each variety 

 and a number of instances were given. Fire produces favorable condi- 

 tions for the multiplication of insects. Even when the trees are only a 

 little injured, the insects find a favorable point of entrance, and working 

 from this point make their way into the tree and seriously injure, if they 

 do not kill it. This is especially true of those species of Cerambycids 

 which work in the heart wood, and which, starting from points of injury, 

 will make their way to the center of the tree where they would not have 

 attacked had it been entirely sound. Scolytids he considers the worse 

 enemies of forest trees, and next to them come the species of Agrilus. 

 He has found A. bilineatus on oak and chestnut, and hickory is also in- 

 jured by a species belonging to this genus. He called attention to the 



