28 
Colorado Experiment Station 
leaves the peach and goes to a large variety of other plants. It returns 
to the peach in the fall to deposit the over-winter eggs upon the twigs. 
This louse also infests the plum. 
Remedies .—Spray after the eggs hatch and before the lice get into 
the opening buds with Black Eeaf 40 (i9)> t part to 800 parts water; 
kerosene eimilsion, 5 to 8 percent kerosene; or miscible oils. If the 
lice appear later, treat as in case of the green apple aphis. 
Black Peach Aphis .—This louse, which is amber to black in color, 
attacks the peach only. It attacks the roots as well as parts above 
ground. It is on the twigs and foliage only until about mid-summer, 
but remains on the roots all the year. 
Remedies .—For those above ground, treat the same as for green 
aphis on apple. For the root form, use the same treatment recom¬ 
mended for the root form of the woolly apple aphis. 
This has not been a serious pest in Colorado, only an occasional 
tree having been found infested. 
Green Plum and Prune Aphis .—This is commonly known as the 
hop plant louse, the hop being the summer food-plant. It migrates to 
the plum and prime in the fall to deposit the over-winter eggs. Winged 
lice return to the hop early in the summer. 
Remedies .—The same as given for the green peach aphis. 
Cherry and Pear Slug .—This is a dark-colored, slimy larva much 
resembling a small snail. The body is large in front and tapers behind. 
It feeds upon the upper surface of the leaves, often leaving only a skel¬ 
eton to wither and die. The adult is a small, glossy black four-winged 
fly about one-fifth of an inch in length. This fly deposits her eggs in 
the tissue of the leaves just under the epidermis by means of a saw¬ 
like ovipositor, whence the commmn name of ‘"saw^-flies.” There are 
two broods each year. This is a common pest on the cherry, pear, 
plum, quince and crabs. See Fig. 9. 
Remedies .—\Vhite hellebore (7) i ounce to 3 gallons of water, 
arsenate of lead (4), Black Leaf 40, i part to 800 or 1,000 parts of 
water; freshly slaked lime (27'). or wood ashes (26) dusted upon the 
slimy larvae will kill many. A strong stream of water will wash them 
from the leaves. 
Fruit-Tree Leaf Roller .—This insect attacks the plum, prune and 
cherry quite severely, and the peach to some extent. (See under Apple). 
Broiirn Mite and Red Spider .—These are often quite bad on 
peaches and plums. For description and treatment, see under Apple 
and Pear. 
