i5 
Two Plant Lice oe the Peach. 
formed, winged lice begin to appear in the colonies; these fly away 
to other food plants, and by the last of June very few can be found 
on peach trees. This is indeed a blessing to the peach grower, for 
should this pest continue its ravages throughout the summer on 
the peach, it would require great effort and expense to control it. 
As it is, trees often suffer a great loss of foliage, and if it weie not 
for the wonderful power of the peach tree to recover after this in¬ 
jury, the result of the aphis attack would be more disastrous. 
Gillette and Taylor, in Bulletin 133, of the Colorado Experi¬ 
ment Station, gave a list of 53 plants growing in the greenhouse, 
which were found to be infested with this aphis, and 25 plants 
growing out of doors, the out-of-door plants comprising most of 
(the common garden vegetables and weeds. The variety of plant.-* 
upon which this louse feeds during the summer time is so great 
that it is probable that it will seldom be plentiful enough on any 
one kind to do serious injury. While on the summer food plants, 
this aphis is usually light yellow in color, and without the green 
stripes so characteristic of it while feeding on the peach. 
Fall Habits .—The last winged generation of lice appearing in 
the fall are known as fall migrants, because of the fact that they 
leave the vegetation upon which the summer has been spent anu 
migrate to peach trees. These fall migrants do not deposit eggs, 
but give birth to the true sexual forms, males and females. The 
females are pink in color, somewhat similar to the stem-mothers 
which were on the trees in the spring, but smaller. After feeding 
for a time and becoming mature they deposit the eggs previously 
described. 
Spraying Experiments .—Because of the abundance of green 
peach aphis eggs last winter, a number of different tests were made 
in the spring, with various insecticides, in ordei to determine their 
value as egg destroyers. The spraying was delayed a little too long, 
however, and on the 7th of March, when the first applications were 
made in the W. C. Strain orchard at Clifton, many of the eggs 
were found to be hatching, and there was no trouble in finding the 
little green lice here and there on the twigs. A great many of the 
eggs were not hatched at that time, hence the various sprays were 
tested as destroyers of both the eggs and the young lice. The bloc^- 
of trees sprayed in the Strain orchard, was only thiee years old, dul 
contained both the eggs of green peach aphis and the hibernating 
larvae of the twig-borer in abundance. The small size of the tiees 
made very thorough spraying possible. The work was done with a 
Morrill and Morley barrel pump, so it was not possible to make the 
applications with a high pressure. Thoroughness was depended upon 
to compensate for the deficiency in pressure. Tests weie made in this 
orchard with Rex lime and sulfur, two strengths, namely: 1 gallon 
