THE PINE-BARK CHERMES: ITS INJURIES. 185 



swellings at the ends of the twigs, resembling in size and form the 

 cones of the same tree. Dr. Thomas, in his 8th Report on the Insects of 



Illinois, 1879, pp. 156-7 has 

 given to this form the pro- 

 visional name of Chennes ahic- 

 \ ticolens. The figure of Dr. 

 Packard is introduced here in 

 illustration of the genus. 

 In Inserts Injurious to For- 



FIG. 49.- CHERMES ABIETICOLENS Thomas. p^^ ^,,^^^ Sluule TvCeS, I 88 I, p. 



234, Dr. Packard, reproduces his remarks and figures from Guide, etc., 

 upon " Adelgesabieticolens Thomas." He also records (p. 235) his ob- 

 servation of "Adelges abiftis Linn." {Clierwes ahietis) of Europe in 

 considerable numbers upon Norway spruces, in Salem, Mass. 



A species quite injurious to the larch in Europe is Chermes lands 

 Hartig. 



Another species depredating upon spruces in Europe has been de- 

 scribed by Kaltenbach as Chermes strobilobivs. 



It is worthy of note that all of the above-named species — eight in 

 number — are confined to coniferous trees. A single species only, so 

 far as known to me, is found upon other vegetation, viz., the Chermes 

 atratiis of Buckton, occurring upon oak {Quercus). 



Injuries of the Insect. 



A tree badly infested with this insect becomes sickly and presents a 

 slender, dwindled appearance; its leaves are short and stinted in their 

 growth, and of a dull green color, and the annual growth of the tree is 

 much curtailed (Fitch). 



Its attack seems usually to be made upon trees that have been trans- 

 planted for the ornamentation of grounds, and is rarely observed upon 

 those that are growing under their native condition. 



According to Prof. Osborn, the Scotch pines in Ames, Iowa, and on 

 the college grounds, were seriously infested for successive years. 



At Fort Dodge, Iowa, the insect was reported as extremely abundant, 

 and was observed literally piled up in the new growth. 



Quite a severe attack was brought to my notice a few years since, 

 through a communication from Tivoli, Dutchess county, N. Y., to this 

 effect: 



I inclose to your address a portion of a pine limb covered with a 



white substance, with the desire that you give me your opinion of what it 



is, and what I can do to remove it. The trees are large pines in the 



avenue, and are looking very badly — in fact, are slowly dying. It does 



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