424 Report oF THE HORTICULTURIST OF THE 
are nearly black in color. Like other species of plant lice they 
multiply with great rapidity, soon covering the under sides of the 
leaves and causing them, to curl and wilt. The lice prefer the 
young leaves at the tips of the branches, and will be found there 
in greatest numbers. 
Treatment.— Where practical cut off and burn the ends of the 
twigs bearing the young and worst infested leaves. ‘The trees 
should then be sprayed with whale oil soap solution or kerosene 
emulsion as recommended for the apple plant louse, page 415. 
SLUG. 
This insect also infests pear trees. It is discussed more fully 
under the heading ‘‘ Pear slug” on page 451. The remedies te 
be used are there given. 
CURRANT DISEASES. 
LEAP SPOT. 
(Septoria ribis Desm. and Cercospora angulata Wint.) 
These two fungous diseases which cause spotting of currant 
leaves have been successfully treated with Bordeaux mixture by 
Pammel.** The spot diseases are usually seen to some extent 
each season, and in some eases their attacks are so severe as to 
nearly defoliate the bushes. Judging from the experiments thus 
far tried, the spraying should begin soon after the fruit sets, and 
continue at intervals of about two weeks until the fruit begins to 
color. One or two applications may be made after the fruit is 
harvested if thought necessary. One objection to the treatments 
before the fruit ripens is that the mixture is liable to remain on 
the fruit and injure its appearance when ripe. 
Goff? has recently reported excellent results from a single 
thorough spraying with Bordeaux mixture made during the first 
week in July, after the fruit was harvested. 
21Pammel, L. H. Jowa Agr. Exp. Sta. Bul. 13: 45-46; Bul. 17: 419-421; 
Bul. 20: 716-718; Bul. 30: 289-291. 
22 Goff, E. S. Wis. Agr. Exp. Sta. Bul. 72: 30. 
