792 
Fig. 1. 
The Cherry Scale, Lulccanium ceraso- 
rum (ekKll) on Pear. Slightly reduced. 
(Original. ) 
Cherry and Pear Slug 
Caliroa cerasi Linn 
H. F. WILSON 
This insect is a common pest of pear, 
cherry, plum and other fruit trees, and 
although not hard to control often causes 
considerable damage. The name “slug” 
cee 
at 
Fig. 1. Cherry Leaves Injured by Slugs. 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
Adult of Cherry and Pear 
Slug. 
Fig. 2. 
is applied on account of the slimy black 
exudation with which the larva  sur- 
rounds itself. 
It appears to be a native of Europe and 
was known as a pest as far back as 1740. 
In America the distribution seems to 
occur with the areas where its principal 
host plants are found. A large number 
of trees, including forest and orchard 
trees, have been reported as attacked by 
this insect, but cherry, pear and plum are 
said to be the favorite plants. 
When present in any locality the larvae 
soon make themselves familiar to the 
fruit grower both by their appearance and 
by the injury which they do. 
In the Northwest we have found but 
two complete broods with some indication 
that there may be a partial third. The 
first adults appear in early spring, but 
for some reason the eggs do not develop 
or are not laid until May or June; as 
soon as they hatch the young larvae be- 
gin feeding on the leaves and from that 
time until the leaves drop the slugs are 
present in varying numbers. Most. of 
them, however, are found in two distinct 
periods: the larvae of the first genera- 
tion appear more abundant during June 
and July; the larvae of the second gen- 
eration are most numerous during Au- 
gust and September. 
Webster has worked out the following 
schedule for Iowa: 
