46 



MISC. PUBLICATION 273, U. S. DEPT. OF AGRICULTURE 



such contact insecticides as nicotine solutions, miscible oil, or lime- 

 sulphur. 



The Montere}^ pine aphid {Essigella calif ornica Essig) is a small, 

 light-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 

 o f 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. 



Bark Aphids 



i>\n uce aloim the W i 

 '11 .spiuce aiiliid (Aijhi 



<t killed 



Large, 



long- 

 brown 



by th(" gV-ec'ii ^piuce aiiliid (Ap/u.^ u6m /OHO. leggeCl, DrOWU OI 



dark-colored plant 

 lice 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 Ponderosa pine and Jeffrey pine. California, 



Nevada, Idaho, and Colorado. 



C. saMnianus Sw Digger pine. California. 



C. arizonica Wilson Pine. Arizona. 



C. edulis Wilson Pinon pine. Colorado. 



