310 THE CANADIAN ENTOMOLOGIST 



Distribution and Economic Importance. — Lecanium corni is 

 found throughout most of the United States and is known to occur 

 as far north as Nova Scotia and Ontario, and south into Mexico. 

 In spite of the wide range of its host plants and its general dis- 

 tribution this insect seldom becomes of economic importance, 

 although serious outbreaks of it have been recorded. In 1891 

 Crawford'' reported its occurrence in California where it had be- 

 come and still remains a serious pest of apricot and prune trees, 

 and in 1894 Slingerland* found a similar and doubtless the same 

 species occurring in destructive abundance in the larger plum 

 growing districts of New York. , 



Food Plants. — The European fruit lecanium, as already indi- 

 cated, has been found on a wide variety of deciduous shrubs and 

 trees, and it has received various popular names in different locali- 

 ties, according to its favorite host plant, being known in New 

 York as the "plum scale," and in California as the "apricot scale". 

 The following list gives an idea of the extent of its food plants. 



AceracecB Acer macrophyllum 



" negundo Box elder. 



" saccharinum Soft maple. 



" saccharum Sugar maple. 



Betulacece Belula alba White birch. 



Ostrya virginiana Hop hornbeam. 



Corylus americana Hazelnut. 



" rostrata Beaked hazelnut. 



Caprifoliacea Viburnum pubescens Pursh. 



Celastracea Evonymus sanguinea Evonymus. 



CompositcB Grindelia spp 



CornacecB Cornus alternifolia 



J " sanguinea 



EricacecB Vaccinium corymbosum High bi sh blueberry. 



FagacecB Caslanea dentata Chestnut. 



Quercus palustris Pin oak. 



" Laurel oak. 



7. Crawford, loc. cit. 



8. Slingerland, Cornell Exp. Sta. Bull. S3, 1894. 



