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to do much harm outside of a small region situated near the foothills 
along the eastern slope of the Rockies in the northern half of Colorado. 
in this region, during the past ten years, they have been very serious 
pests. C. semiferana confines its attacks in the region mentioned 
entirely to the box-elder, while C. argyrospila isa very general feeder, 
being able to subsist upon the foliage of almost any deciduous tree or 
shrub. I have seen small orchards entirely defoliated by this species 
so that not a green leaf could be seen, and the box-elder species has 
been equally destructive to the foliage of that tree. At present these 
insects have nearly disappeared in “genic County, but they are still 
very destructive in the vicinity of Denver and Boulder. 
The case seems to be one where two closely-related insects reached, 
at about the same time, a region where their fcod-plants were abund- 
ant and their enemies scarce. As they have risen and fallen together 
in numbers, it seems probable that they are controlled in a state of 
nature by the same checks. We have bred not less than ten Bee of 
parasites from them. 
The habit of the female of C. semzferana in shingling her egg patches 
with the large flat scales from the underside of her abdomen is unique 
among insects so far as the writer Is aware. Does anyone present 
know of a similar habit in another species / 
The peach-twig borer, Anarsia lineatella, has become a serious 
enemy in peach orchards on the western slope within the State. It 
has done much injury this year in pruning back the new growth on 
young trees, and promises to occasion a heavy loss of fruit a little 
later as the first brood has matured in large numbers. The most 
promising remedy so far seems to lie in the use of bands upon the 
trunks of the trees for capture of the larvee, as in case of the codling 
moth. 
The peach borer, Sannina exitiosa, is present in the peach-growing 
sections, but for some reason does not do serious harm as yet. 
_ The currant borer, Sesta tipuliformis, is as abundant in the north- 
ern portion of the State as I have ever known it anywhere. 
The woolly plant louse, Schizoneura lanigera, probably ranks next 
to the codling moth in importance as a pest in apple orchards in the 
State, and is particularly abundant on the west slope. Tobacco dust 
is taking the lead as a remedy for the root form. The number of 
trees actually killed by this insect in the State have been quite small. 
The pear and cherry tree slug, Lriocampoides ‘limacina, is very 
destructive, particularly to pear foliage, wherever remedies are not 
promptly applied for its destruction. It is worst at present on the 
western slope. 
The San Jose scale is as yet unknown within the State. The only 
member of the family Coccide that has attracted any special attention 
Aspidiotus ancylus, which I have seen rather abundant on several 
