THE OYSTER-SHELL SCALE 
Buckthorn (Rhamnus cathartica Linn.). 
Cherry, choke (Prunus virginiana Linn.). 
Cherry, wild black (Prunus serotina 
Ehrh.). 
Cherry, wild red (Prunus pennsylvanica 
Linn.). 
Chokeberry, black (Aronia melanocarpa 
[Michx.] Elliott. 
Chokeberry, red (Aronia arbutifolia [L.] 
Pers. 
““Cherry currant.’’ 
Cotton (Gossypium sp.). 
Currant, black (Ribes nigrum). 
Currant, red flowered (Ribes sanguineum 
Pursh.), England. 
Elm( Ulmus sp.). 
Gooseberry (fibes sp.). 
‘Hawthorn (Crataegus oxyacantha Linn.). 
Hickory, big bud (/Ticoria alba Britt.). 
Horse chestnut (Aesculus hippocastanum 
Linn.). 
AND THE SCURFY SCALE. 9 
Maple (Acer sp.). 
Peach (Amygdalus persica L.). 
Pear (Pyrus communis Linn.), (P. hetero- 
phylla Dur.) (P. melanocarpa). 
Plum, purple-leaved (Prunus pissardii 
Hort.). 
Plum, common garden (Prunus domestica 
Linn.). 
Quince (Cydonia vulgaris Pers.). 
Quince, Japan (Chaenomeles japonica 
[Thunb.] Lindl.). 
Raspberry, black cap (Rubus occidentalis 
Pers.). 
Red-twigged dogwood (doubtful record). 
Shad-bush (Amelanchier canadensis Me- 
dic.). 
Sweet gum (Liquidambar styraciflua). 
Sweet pepper bush (Clethra alnifolia 
Linn.). 
Walnut, black (Juglans nigra Linn.). 
Willow. white (Salix alba Linn.). 
The scurfy scale is especially common on apple and pear, less usu- 
ally so on cherry and peach, on which latter host in the South, in cer- 
tain cases which have come under the writers’ observations, it proved 
very destructive, greatly stunting the trees, although none had actu- 
ally been killed. 
PARASITIC AND PREDACEOUS ENEMIES. 
This species is apparently not so subject to attack of parasitic and 
predaceous insects as the preceding, or else attention has not been 
directed to this phase of the insect’s economy to an equal extent.! 
METHODS OF CONTROL FOR BOTH SPECIES. 
Preparatory to spraying orchard, shade, and ornamental trees and 
plants for scale insects, they should be carefully gone over and any 
dead and weakened parts pruned out. The presence of such dead 
and dying wood is a distinct detriment, and its removal will greatly 
simplify the work of spraying. 
TREATMENT OF ORCHARDS. 
In orchards well sprayed during the dormant period for the San 
Jose scale each year, the oyster-shell and scurfy scales should rarely 
prove troublesome. While these insects, by reason of their winter- 
ing in the egg stage under the protecting female scales, are less sus- 
ceptible to washes effective against the San Jose scale, yet the treat- 
ments will in most cases keep them reduced below injurious numbers. 
‘The following predaceous species are recorded as feeding upon the scurfy scale: Tyroglyphus malus 
(Shimer), Chilocorus bivulnerus Muls., and Hyperaspidius sp. 
Among the parasitic Hymenoptera Ablerius clisiocampae (Ashm.) has been reared from this species 
as Well as Physcus varicornis How., and a species of the genus Prospaltella. 
