INSECTS AKFECTINC PARK AND WOODl.ANU TREES 60I 



Birch aphid 



CallipUriis bcl/t/accolcns Mon. 

 A delicate yellowisli plant louse is sometimes exceedingly alMindant in niidsiininu-r 

 on tiie underside of birch foliage. 



This little specitts is sometimes very injurious to hirclies in tlu; \icinil)' 

 of Albaii)', particular!)' the ornamental cut-leaved varietx', and it is occa- 

 sionally quite destructive in other portions of the State, complaints of its 

 depredations havinj;' been received from Herkimer county anil also in the 

 \icinity of Buffalo. Fhere is no method of keeping it in check aside from 

 spraying with contact insecticides such as a whale oil soap solution or 

 kerosene emulsion ami ordinaril)- that is impractical. The pest, when 

 abundant, is fed on to a considerable extent by adidts antl larvae of the 

 two-spotted lady beetle, A d a 1 i a b i p u n c t a t a Linn. 



■Woolly beech leaf aphis 



J^hyllaphis fagi Linn. 



Cottony masses occurring on the underside of purple beech leaves usually shelter 

 grou|)S of this jjlant louse. 



This species is a common one on purple beech in parks, and sometimes 

 becomes so abundant as to cover a large proportion of the under surface 

 of the leaves and at such times it may cause considerable injury to the tree. 



Description and habits. This aphid is shown clustered on the under- 

 side of leaves and along the mid ribs and smaller veins on plate i i, figures 

 lo, II. The adult females may be recognized by the conspicuous cottony 

 tufts largely concealing the bod)-. The young are pale greenish yellow and 

 may frequently be .seen nestling among the hairs so abundant along the leaf 

 veins. The cast skins or exuviae are snow-white, sometimes abundant and 

 may then give a whitish appearance to the underside of the foliage. The 

 partly grown plant louse has the habit of resting with its head close to a 

 vem, from which it is apparent!)' drawing nourishment. The extremity of 

 the young is usually ornamented by a few scattering bluish, white fibers. 



