336 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



The Monterey, Guadalupe, and Arizona cypresses and incense cedar 

 are attacked, while the Italian and Oriental cypresses are immune. 

 This is such a pest that it is even recommended that other trees be 

 planted instead of these cypresses in badly infested regions. 



The black scale, Saissetia oleoe (Bern,), is a pest of shade trees as 

 well as friiit trees. In the interior regions it apparently does little 

 harm, but in the San Francisco Bay Region it is a particularly harmful 

 pest on oleanders and in southern California on pepper trees. It also 

 infests a great many other native and foreign plants. 



The mealy-bugs are quite a problem by themselves. The citrus 

 mealy-bug, Pseudococcus citri (Risso), is almost entirely a southern 

 California pest, as is also the long-tailed mealy-bug, P. longispinus 

 (Targ.). In the rest of California these are mostly greenhouse pests. 

 P. maritimus (Ehrh.) {bakeri Essig) is quite a cosmopolitan pest, 

 occurring in a great many parts of the state and on a variety of host 

 plants, including a number of shade trees. 



P. gahani Green (citrophilus Clausen), known as a citrus pest 

 of Southern California, is also a shade tree pest occurring on a number 

 of trees. It has spread rather recently to central California, the writer 

 having found it on black locust at Burlingame, and on Pittosporum, 

 olive, fig, Poinsettia and rose at Oakland, California. It has also been 

 previously reported from Niles, California. 



The golden mealy-bug, P. aurilanatus (Mask.), is a very harmful 

 pest upon Araucarias and Agathis in Southern California. Araucaria 

 hidwilh seems to suffer the worst, with A . excelsa next and A . imbricata 

 third. Many appear black and dilapidated, while numerous dead 

 or dying trees are reported to have been removed. 



The sycamore scale, Stomacoccus plata7ii Ferris, although a newly 

 described scale insect, apparently is quite widespread, infesting both 

 the native sycamore and the European plane tree. The writer has 

 already located it at Los Gatos, San Jose, Evergreen, Livermore, 

 Fresno, Claremont and Pasadena, California. It was noticed doing 

 considerable damage in several of these localities. 



Some of the other important shade tree scale insects are: the Mon- 

 terey pine scale, Physokermes insignicola (Craw.), which infests Mon- 

 terey and other pines; Tourney ella sp., which infests the Austrian and 

 Monterey pines; the Cahfornia pine leaf scale, Aspidiotus pini Corn- 

 stock {californicus Coleman), infesting most of the common pines; the 

 cottony cushion scale, Icerya purchasi Mask., which does particular 

 damage to boxwood and acacias; the rose scale, Aulacaspis rosae 

 (Bouche), collecting in great numbers on the stems of roses, where it is 

 quite conspicuous, occasionally doing some damage; the Itahan pear 

 scale, Epidiaspis piricola (Del Guercio), which does considerable 



