Clje diaimbian Entomologist. 



VOL. XVr. LONDON, ONT., AUGUST, 1884. No. 8 



ENTOMOLOGY FOR BEGINNERS. 



PULVINARIA INNUMERABFLIS, Rathvon. 



HY THF. F.DITOR. 



This insect, which has commonly been known as the Grape-vine Bark- 

 louse, might with perhaps greater propriety be now designated the Maple- 

 tree Bark-louse, for the reason that it has been more frequently found on 

 maples, and inflicted more injury on these trees, than it has on grape 

 vines. The great abundance of this insect during the past season has 

 called general attention to it and elicited many enquiries in reference to 

 its history and habits ; indeed, in many sections of Western Ontario, as 

 well as in the adjoining States of Michigan and New York, it has appeared 

 in such swarms as to endanger the lives of the trees attacked. Branches 

 have been sent to us so thickly covered with the insect in its various stages 

 of growth that they could not be handled without crushing some of the 

 numerous population. 



The earliest description of this insect was given by Dr. S. S. Rathvon, 

 of Lancaster, Pa., in 1854, who at that time gave the results of several 

 years' observation on this species, which had occurred in his neighborhood 

 on the Basswood or American Linden trees (Tilia americana). He 

 found them to swarm in such countless hosts that he gave the insect the 

 significant name of itirmmerabiiis. The late Dr. Fitch next published an 

 account of it in the Transactions of the N. Y. State Agricultural Society 

 for 1859, since which several authors have figured and described this 

 insect ; but its life history was not fully unfolded until taken in hand by 

 the late lamented J. D. Putnam, of Davenport, Iowa, who published in 

 1879, i" th^ Report of the Davenport Academy of Sciences, a most 

 elaborate and complete description of its hfe history, illustrated 

 with two plates crowded with figures representing the various stages 

 of development, all drawn by himself from nature. To these several pub- 

 lications we are mainly indebted for the facts here presented. ' 



