INSECTS AFFECTIXG PARK AND WOODLAND TREES 1 93 



reduces the vitality of a tree and apparently leads to a sickly condition, 

 which, in a few cases, appears to have eventually resulted in death. It is 

 impossible to say that this plant louse is the sole cause of the injur)- but 

 our obserw'itions intlicate this to be probable in some instances. 



Early history. This insect was noticed by Dr Fitch in 1856. He states 

 that it was more troublesome to ornamental trees and described its treneral 

 appearance and also the insect. It was noticed in 1883 by Mr Saunders, 

 who records it as a species which is sometimes very destructive to the white 

 pine, and one which is preyed on by a number of natural enemies. In 1885 

 Dr Lintner gave a somewhat extended ncitice of this plant louse, presum- 

 ably on account of its abundance on pine in the vicinity of Alban^;. 

 Dr E. P). .Southwick. entomologist of the Department of Public Parks of 

 New York city, stated in 1894 that this insect gave him a great deal of 

 trouble and that he found a stiff spray was one of the best methods of 

 subduing it. Prof. Lawrence Bruner, in the same year, stated that he had 

 received reports of injuries by this species from several localities in 

 Nebraska. A detailed notice of this plant louse by E. L. Storment ' 

 appeared in 189S, in which he states that this insect has been quite inju- 

 rious in Illinois. This last writer lists the insect as occurring in a number 

 of Illinois. New York, Iowa and Maryland localities, and adds that it is 

 probably much more generally distributed than the few localities which he 

 has been able to find recorded, would seem to indicate. 



Life history. The life history of this insect has not been worked out 

 in detail. The eggs commence to hatch early in Ma)' in favorable seasons, 

 af which time the young emerge in large numbers from their protective 

 balls of W'Ooll)' matter and travel actively over the bark for a time. They 

 are so small as to be nearly invisible to the naked eye and in the early part 

 of May they are more abundant than at any other time. Traveling soon 

 ceases and they attach themselves to the tender bark of )-oung twigs. 

 They increase rapidly in size, assume a dark reddish brov.'n color approach- 

 ing black, and the secretion from the body commences and soon hides them 

 ' 1898. E. L. Storment. Ins. of 111. 20th Rep't, ap. p. 3-24 



