NEW YORK STATE MUSEUM 



abundance. Professor Lowe has observed them at Geneva N. Y., as early 

 as May 7. They soon settle in a place and begin sucking nourishment 

 from the underlying bark tissues, and in about 2 days, white waxy filaments 

 extend from the back of the young, and when numerous, the infested 

 branches are adorned with patches of white woolly matter. This excre- 

 tion mats down and soon forms a protective covering which is supple- 

 mented later by the cast skins of the insect. Fully developed females may 

 be found about the first of August and egg laying begins soon after and is 

 completed by the latter part of the month or early in September. One 

 female deposits from 50 to 100 eggs. 



Food plants- This 

 species is of economic 

 importance chiefly on 

 account of its depreda- 

 tions on some of our 

 more valuable fruit trees 

 as previously pointed out. 

 It also occurs on ash and 

 poplars in considerable 

 numbers and has been 



Fig. 35 -A.spid 



ly enlarged. (After Howard. 



2<)> recorded on willow, lin- 



den, horse-chestnut, elm, sugar and swamp maple. 



Natural enemies. A small hymenopterous maggot was observed by 

 Dr Fitch to live on the eggs of this pest. What was in all probability the 

 same parasite was described by Dr Le Baron some years later as A p hel i- 

 n u s m y t i 1 a s p i d i s, which he found had destroyed from about 50;^ to 

 6o;« of the scales. Aphelinus fuscipennis How. is recorded as a 

 most efficient parasite of this scale in California. A s p i d i o t i p h a g u s 

 citrinus Craw, has been reared from this pest in that state. The 

 accompanying figure will give a good idea of the appearance of these tiny 

 Chalcids. The best evidence of their work is the small circular holes in 

 the dead scales, orifices by which these little friends have escaped. 

 Aphelinus a b n o r m i s How. is another parasite of this bark louse. 

 Anaphesgracilis How. and Chiloneurus d i as p i d i n a r u m 

 How. have also been reared from this insect. 



