A6 MISC. PUBLICATION 273, U. S. DEPT. OF AGRICULTURE 
such contact insecticides as nicotine solutions, miscible oil, or lime- 
sulphur. 
The Monterey pine aphid (£'ssigella californica Essig) is a small, 
hight-green, pear-shaped insect about one-eighth of an inch in length 
and with very long hind legs. It is reported as feeding on the 
needles of Monterey pine, ponderosa pine, and Douglas fir in Cali- 
fornia and Oregon. 
Schizolachnus pini- 
radiatae Davidson 
is a dark-green 
aphid, much small- 
er than the last 
named and covered 
with a cottony wax. 
This species attacks 
the needles of Mon- 
terey and other 
pines in central 
California. S. to- 
mentosus DeG. is a 
yellow to brownish- 
black species which 
lives on the needles 
of ponderosa pine 
in Colorado. There 
are a large number 
of species that in- 
fest the leaves of 
various broad- 
leaved forest trees, 
but these are of lit- 
tle importance from 
the forestry stand- 
point. 
4 
pant eat: 
ponte 
besiege ont ny ae 
sit 
. 
. 
BARK APHIDS 
F 20.—Sitl long the Wash kill ee ee 
IGURE 20.—Sitka spruce along the Washington coast kille ae FS 
by the green spruce aphid (Aphis abietina). : legged, br Own OF 
dark-colored plant 
hee with naked bodies or lightly covered with a powdery wax belong 
to the genus Cinara (Dilachnus). They are frequently found feed- 
ing on the terminal twigs of coniferous trees, where they insert their 
beaks through the tender bark. The copious flow of honeydew 
causes a dense smutting of the trees, sometimes making them appear 
as if they had been sprayed with creosote. At times their work 
causes considerable injury. 
The following species are recorded from the Western States: 
Species of Cinara Hosts and distribution 
C. ponderosa) WMS. 20 eee Ponderosa pine and Jeffrey pine. California, 
Nevada, and Colorado. 
C2SQ0INAG USES Wes = ee eee Digger pine. California. 
C2 drizonica, WNW ison- 222 =e Pine. Arizona. 
Ci earliseWwalson]-= 222-42 ee Pifion pine. Colorado. 
