Insects Injurious to Shade Trees. 



By JOHN B. SMITH, Sc.D., State Entomologist. * 



GENERAL CONSIDERATIONS. 



Iii the following pages it is intended to refer to the lead- 

 ing species of insects infesting shade trees in the briefest 

 possible manner only and to give, in the same way, directions 

 for treatment. If further details are desired concerning 

 the habits or characters of the insects referred to, they can 

 be found in the Bulletins and Reports of the Fuller in- 



-v T A -n n formation 



.New Jersey Agricultural Experiment Stations, obtainable. 

 to which reference is also made for further information con- 

 cerning insecticides and insecticide machinery. 



The colored plates exhibiting the more important insects 

 were prepared by Mr. John A. Grossbeck, then an assistant 

 in the author's laboratory. The drawings were made from 

 published figures, credited as to source in Bulletin 181 of 

 the Xew Jersey Agricultural Experiment Stations. 



The order in which the insects are referred to here, is an 

 indication of their relative importance. 



THE ELM-LEAF BEETLE. 

 PL IV., Figs. 5, 5a, 5b. 



The adult beetle lives through the winter, hiding in attics 

 and other sheltered places. When the first elm leaves are 

 full grown in spring it becomes active, begins eating irregu- 

 lar holes through the leaves and, in about a week, lays eggs. 

 These hatch into yellow and black slugs which At taeks 

 feed on the underside of the leaves, eating only elms only - 

 the surface layer of cells, and cause them to turn brown, dry 

 and drop. Early in July the larvae crawl to the base of the 



*Died March 12th, 1912. 



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